F-35 shown obsolete on previous posts
Accidents involving small private planes are investigated but they do not have flight recorders like commercial aircraft. This makes the work of the accident investigators much more difficult.
A simple improvement would be to have a recorder about the size of a pack of playing cards attached to the plane's dashboard. It would have an ambient microphone to record conversation and general aircraft noises and three axis motion and rotation measurements/
It should cost only a few hundred dollars if built into s new plane and maybe a few thousand dollars to retrofit existing aircraft. It can be built much more simply than commercial aircraft recorders because the enery of ground collision is much less. The total fuel heating from fire would also be less and frequently small planes crash without burning. It could have a lithium battery to record after engine failure. The cost would be low because it would have no connections to the aircraft controls. This limits the amount of information gathered, but it would atill be a major improvement for accident investigators over currently having nothing.
Saturday, April 28, 2012
Thursday, April 26, 2012
Scientific learning
F-35 shown obsolete on previous posts
One of the disappointments of engineering and science ids the refusal to use science to teach science. The claimed methodology of science is to create a model then measure and evaluate the model before continuing it or rejecting it. This is not done in instruction. Each instructor chooses to teach in any manner he desires with out regard to its results.
It would make more sense to test students as well as having them fill out surveys to determine satisfaction and assessment of knowledge gained. The next step is to promote the methods that work and discontinue the ones that do not. It might actually improve the efficiency of education.
It might not be possible or desirable to standardize across all curricula, there is too much diversity in student ability across schools and departments. But it should be possible over time within one school to evaluate and improve the methodology, and it might have some applicability to other schools.
A fair amount of variety in teaching methodology should be encouraged, but it must be evaluated and the better parts adopted generally.
One of the disappointments of engineering and science ids the refusal to use science to teach science. The claimed methodology of science is to create a model then measure and evaluate the model before continuing it or rejecting it. This is not done in instruction. Each instructor chooses to teach in any manner he desires with out regard to its results.
It would make more sense to test students as well as having them fill out surveys to determine satisfaction and assessment of knowledge gained. The next step is to promote the methods that work and discontinue the ones that do not. It might actually improve the efficiency of education.
It might not be possible or desirable to standardize across all curricula, there is too much diversity in student ability across schools and departments. But it should be possible over time within one school to evaluate and improve the methodology, and it might have some applicability to other schools.
A fair amount of variety in teaching methodology should be encouraged, but it must be evaluated and the better parts adopted generally.
Tuesday, April 24, 2012
Army cargo
F-35 shown obsolete on previous posts
The movement of logistics is the first challenge of modern militaries. The use of containers had revolutionized cargo movement, it could similarly change military logistics.
For military usage, containers could be built each of which would be 1/3 the length of a standard container. 3 of them could be clamped together and shipped and moved as a standard container. On arrival at the destination shipping port, they would be separated and placed on a 5 ton truck for resupplying forward units.
A standard container is 8 feet wide and 9 feet high. For military usage, they would be 8 feet wide and 6 1/2 feet high, allowing an internal height of 6 feet, the remainder being structure. It would be a bit of a head knocker but soldiers wear helmets.
The advantage is that the packaging and sorting would be done in the U.S., simplifying logistics and allowing fewer logistic personnel being needed at the forward location.
The one one drawback is that the density of cargo might be lower to avoid overloading the truck. That would mean less cargo in each 3 set than a standard container, which would require more containers and more ships, although more containers could be shipped with each of lower height. The stacked height of containers,and the raised center of mass they create, limits container carriage on ships. Additionally, 4 cargo boxes rather than 3 could be in the length of 1 container rather than 3.
The other weak point is that the clamps must be highly reliable or there will be a significant risk of the boxes separating and being dropped when lifted by cranes.
For military usage, containers could be built each of which would be 1/3 the length of a standard container. 3 of them could be clamped together and shipped and moved as a standard container. On arrival at the destination shipping port, they would be separated and placed on a 5 ton truck for resupplying forward units.
A standard container is 8 feet wide and 9 feet high. For military usage, they would be 8 feet wide and 6 1/2 feet high, allowing an internal height of 6 feet, the remainder being structure. It would be a bit of a head knocker but soldiers wear helmets.
The advantage is that the packaging and sorting would be done in the U.S., simplifying logistics and allowing fewer logistic personnel being needed at the forward location.
The one one drawback is that the density of cargo might be lower to avoid overloading the truck. That would mean less cargo in each 3 set than a standard container, which would require more containers and more ships, although more containers could be shipped with each of lower height. The stacked height of containers,and the raised center of mass they create, limits container carriage on ships. Additionally, 4 cargo boxes rather than 3 could be in the length of 1 container rather than 3.
The other weak point is that the clamps must be highly reliable or there will be a significant risk of the boxes separating and being dropped when lifted by cranes.
Saturday, April 21, 2012
Jet pigeon
F-35 shown obsolete on previous posts
One of the dangers of modern militaries is the loss of communications satellites, they are easily destroyed because their paths are predictable. A possible back-up is to build a drone with a range of 12 000 miles, 24 000 miles being the circumference of the globe. It would be able to fly to the host country like a homing pigeon from any point on the globe.
In appearance it would be similar to a U-2, but unmanned and smaller. It would have data storage on board for all routine but non time critical military information. It would have a cruising speed of 500 mph at an altitude of 60 000 feet. It would be lifted and recovered by manned planes, which would save the weight of landing gear and allow the wings to be designed exclusively for cruising flight. It would be flown to 40 000 feet and released. It might take it 24 hours toreach its home base, but it would free up radio circuits for critical work.
A 50% fuel fraction should be achievable. For 24 hours, that would be 2% per hour. If the engine burns 1 lb of fuel for each pound of thrust, specific fuel consumption of 1.0, which should be achievable, it would need a weight to thrust of 38 to 1, average weight is 1/2 of 100% + 50% = 75% divided by 2%. Powered gliders can achieve 50 to 1, unpowered gliders, 75 : 1.
One of the dangers of modern militaries is the loss of communications satellites, they are easily destroyed because their paths are predictable. A possible back-up is to build a drone with a range of 12 000 miles, 24 000 miles being the circumference of the globe. It would be able to fly to the host country like a homing pigeon from any point on the globe.
In appearance it would be similar to a U-2, but unmanned and smaller. It would have data storage on board for all routine but non time critical military information. It would have a cruising speed of 500 mph at an altitude of 60 000 feet. It would be lifted and recovered by manned planes, which would save the weight of landing gear and allow the wings to be designed exclusively for cruising flight. It would be flown to 40 000 feet and released. It might take it 24 hours toreach its home base, but it would free up radio circuits for critical work.
A 50% fuel fraction should be achievable. For 24 hours, that would be 2% per hour. If the engine burns 1 lb of fuel for each pound of thrust, specific fuel consumption of 1.0, which should be achievable, it would need a weight to thrust of 38 to 1, average weight is 1/2 of 100% + 50% = 75% divided by 2%. Powered gliders can achieve 50 to 1, unpowered gliders, 75 : 1.
Thursday, April 19, 2012
Inefficiency
F-35 shown obsolete on previous posts
One of the biggest drains on U.S. defense spending is that the congress members use it as a jobs program. There is a constant proliferation of defense plants to supposedly create local jobs. This guarantees that all production is low rate and inefficient.
Everyone would be better off in the long run if the defense plants were consolidated in a rather small geographic area by type; the armor vehicle production in one area, the ships in one ship yard complex,aircraft in a cluster of plants. The employees would move from one plant to another as needed. This might require the rewriting of anti-trust legislation.
Equipment would be built in pulses; one type of aircraft would be built for one year and then the production line would be mothballed until production restarts. There would only be enough employees left to perform maintenance. All the other employees would then move to another plant within a few miles and produce a different product for another year. They would produce fighter planes for one year and then tanker aircraft the next and then possibly helicopters in the third year before returning to fighters.
Buiolding larger numbers in one year tends to lower costs. It also allows for design changes to be incorporated in one type and that type produced in useful quantities.
The employees would move potentially from one employer to another, but that can be arranged if everyone acts like adults. Each employer would contribute by time employed into pension funds.
For ship building, instead of building one ship at a time, destroyers would be built in clusters of four. Modern shipbuilding involves building ships in sub-units and then assembling them. If a destroyer is built in twelve sections, four section 6s would be built, then four section 5s which would be assembled. This saves money. It would mean having only one shipyard for government contracts. Aircraft carriers would be built in pairs, again, to save money and increase efficiency.
One of the biggest drains on U.S. defense spending is that the congress members use it as a jobs program. There is a constant proliferation of defense plants to supposedly create local jobs. This guarantees that all production is low rate and inefficient.
Everyone would be better off in the long run if the defense plants were consolidated in a rather small geographic area by type; the armor vehicle production in one area, the ships in one ship yard complex,aircraft in a cluster of plants. The employees would move from one plant to another as needed. This might require the rewriting of anti-trust legislation.
Equipment would be built in pulses; one type of aircraft would be built for one year and then the production line would be mothballed until production restarts. There would only be enough employees left to perform maintenance. All the other employees would then move to another plant within a few miles and produce a different product for another year. They would produce fighter planes for one year and then tanker aircraft the next and then possibly helicopters in the third year before returning to fighters.
Buiolding larger numbers in one year tends to lower costs. It also allows for design changes to be incorporated in one type and that type produced in useful quantities.
The employees would move potentially from one employer to another, but that can be arranged if everyone acts like adults. Each employer would contribute by time employed into pension funds.
For ship building, instead of building one ship at a time, destroyers would be built in clusters of four. Modern shipbuilding involves building ships in sub-units and then assembling them. If a destroyer is built in twelve sections, four section 6s would be built, then four section 5s which would be assembled. This saves money. It would mean having only one shipyard for government contracts. Aircraft carriers would be built in pairs, again, to save money and increase efficiency.
Tuesday, April 17, 2012
Flying trailers
F-35 shown obsolete on previous posts
There was a tornado near Dallas, Texas that lifted truck trailers.
For a trailer to be lifted, there must be either:
In C, if the wind is at an angle to ground of 30 degrees, with the same factor of 0.8, the weight density would be 33 psf for v^2 of 26 000, but only 0.5 of velocity would be incident on trailer. However, there would be a vacuum above the trailer that would match in theory the pressure force below. That would reduce the need force by 0.5 but with the wind speed vertical of 0.5 speed, v^2 = 26 000 X 2 = 52 000 orwind speed 230 fps, 160 mph, 260 kph.
To fly, the trailers would have no inherent aerodynamic lift. The square corners would prevent circulatory flow and would violate Kutta's hypothesis. The vertical sides height be 10 ft high. If the trailer is rolled so the side is 30 deg to the horizontal;
The sides are 2 x 10 x 0.5, wind angle x 0.87 cosine of lift
The top an bottom are 8.5 x 2 x .87, wind angle x 0.5 lift cosine
The effective area is 8.7 - 7 = 1.7 ft width.
For 53 ft = 90 ft^2 or 133 psf
Wind speed would be 340 fps, 230 mph, 370 kph.
The equation of force goes as 2 X (L1 - L2) X sin 2x, where x is the angle of inclination and L1, L2 are the lengths of sides. This has to br multiplied by the effective adjustment of thearea for edge effects.
There was a tornado near Dallas, Texas that lifted truck trailers.
- a wind such as B, blowing harder above the trailer than below to cause a greater pressure drop and therefore produce lift
- a wind such as C, that deflects upwards from the ground and produces lift through stagnation pressure
In C, if the wind is at an angle to ground of 30 degrees, with the same factor of 0.8, the weight density would be 33 psf for v^2 of 26 000, but only 0.5 of velocity would be incident on trailer. However, there would be a vacuum above the trailer that would match in theory the pressure force below. That would reduce the need force by 0.5 but with the wind speed vertical of 0.5 speed, v^2 = 26 000 X 2 = 52 000 orwind speed 230 fps, 160 mph, 260 kph.
To fly, the trailers would have no inherent aerodynamic lift. The square corners would prevent circulatory flow and would violate Kutta's hypothesis. The vertical sides height be 10 ft high. If the trailer is rolled so the side is 30 deg to the horizontal;
The sides are 2 x 10 x 0.5, wind angle x 0.87 cosine of lift
The top an bottom are 8.5 x 2 x .87, wind angle x 0.5 lift cosine
The effective area is 8.7 - 7 = 1.7 ft width.
For 53 ft = 90 ft^2 or 133 psf
Wind speed would be 340 fps, 230 mph, 370 kph.
The equation of force goes as 2 X (L1 - L2) X sin 2x, where x is the angle of inclination and L1, L2 are the lengths of sides. This has to br multiplied by the effective adjustment of thearea for edge effects.
Saturday, April 14, 2012
city streets
F-35 shown obsolete on previous posts
If one were to build a new city, it might be desirable to actually separate car and truck traffic. Ultimately,the only way of controlling car traffic is to let it grow until it chokes itself off, no other effective means has ever been found to regulate it. But trucks are essential to the functioning of a city, there traffic should not be impeded.
The truck streets could alternate with the car streets, B. The blocks would be divided into building lots that stretch from the truck street to the next car street. The property developer would be responsible for integrating truck access into the building plans.
At A, is shown a possible cross section of the street. There could be an elevated pedestrian plaza above street level. To accommodate trees, cast iron cylinders of 10 foot diameter could be installed from the natural soil to the plaza level. The cylinders would be filled with planting material and trees planted within them. The cast iron should preclude tree roots rupturing the container.
Enclosed, elevated walkways would be run above the center of the street. Similar walkways have been built in Minneapolis, Minnesota to protect pedestrians from sever weather. Connecting walkways would extend from the building fronts to the walkway. Bicycle routes could be built on the top of the walkways, allowing bicyclists unimpeded movement.
Mass transit would entail having what would amount to horizontal elevators that would be slung beneath the pedestrian walkway. This protects them from snow and ice, so they would never be non-operational. By elevating them above the street, they are not slowed by traffic jams.
At c, is shown a pattern of cross bridges, perhaps 4 per block, to allow a smooth flow of people back and forth a across the street without the need for pedestrian crossings to slow traffic.
There could be additional businesses and taxi stops at street level.
The truck and car routes could have roundabouts rather than traffic lights to allow for a smoother flow of vehicles. The center of the roundabouts could be connected to one block in the direction disallowed by traffic. The centers could then be used as mini-parks.
ASt some point, there will be an inevitable mixing of cars and trucks, but minimizing the common usage should allow for better truck movement.
At A, is shown a possible cross section of the street. There could be an elevated pedestrian plaza above street level. To accommodate trees, cast iron cylinders of 10 foot diameter could be installed from the natural soil to the plaza level. The cylinders would be filled with planting material and trees planted within them. The cast iron should preclude tree roots rupturing the container.
Enclosed, elevated walkways would be run above the center of the street. Similar walkways have been built in Minneapolis, Minnesota to protect pedestrians from sever weather. Connecting walkways would extend from the building fronts to the walkway. Bicycle routes could be built on the top of the walkways, allowing bicyclists unimpeded movement.
Mass transit would entail having what would amount to horizontal elevators that would be slung beneath the pedestrian walkway. This protects them from snow and ice, so they would never be non-operational. By elevating them above the street, they are not slowed by traffic jams.
At c, is shown a pattern of cross bridges, perhaps 4 per block, to allow a smooth flow of people back and forth a across the street without the need for pedestrian crossings to slow traffic.
There could be additional businesses and taxi stops at street level.
ASt some point, there will be an inevitable mixing of cars and trucks, but minimizing the common usage should allow for better truck movement.
Thursday, April 12, 2012
Raising fish
F-35 shown obsolete on previous posts
There is an increasing demand for fish while native stocks are being stressed by over fishing. The obvious solution is to raise fish. There are difficulties of fish parasites and disease outbreaks in close confinement when they are raised in ocean pens. An alternative is to build large enclosed fish-rearing tanks.
The structure could be built with concentric rings, A. The overall facility might be 1000 meters across with each ring 20 meters across and 20 m deep. The rings would be connected with short tunnel sections, B, to allow the fish to be moved successively outwards as they mature and grow larger. The younger fish, being smaller, would be accommodated nicely in the smaller internal rings. The structure between the rings might be 5 m wide.
For 1000 m width and allowing 200 m for a center portion for early growth tanks and support equipment and facilities, there would be 16 rings. The average diameter would be about, 1000 + 200 = 1200/ 2 = 600 m for a circumference of 1800 m. With a depth of 20 m; 1800 X 20 X 20 X 16 rings =
12 000 000 cubic meters, m3. The question then becomes how tightly to pack the fish.
If the fish are stocked at 1 / 40 the volume, apparently tighter packing is possible, and one assumes that the fish double in size each year over a 3 year growth cycle, the fish would need 1 volume in year 1, 2 volumes in year 2, and 4 volumes in year 3, actually there would be somewhat more available for year 3 as the fish do not spontaneously double in size, or 4 / 7, 57%, would be harvested, so
12 000 000 X .57 / 40 = 170 000 metric tonnes of fish harvested annually. Allowing a net yield of 50% weight for fillets, = 85 000 000 kilograms of salable weight annually.
For a structure of 1000 m by 1000 m, if the construction costs are $5000 / square meter, m2, the total cost would be $5 000 000 000 ($5 billion). If financing is at 5%, the structure should last at least 50 years,so amortization could be adjusted for that period, the finance costs would be $250 000 000 /yr or $3 per kilogram of salable fish.
There was a report some 10 years ago that said fish processors in Norway were shipping fish to China for processing before returning them for sale in Norway. The claim was that shipping and processing in China cost over $1.50 / kg, while Norwegian processing cost some $3.00 / kg. As fuel prices rise, the cost of shipping rises and the total cost of shipping and processing.
Machines have been built as test equipment that can automatically; cut off fish heads and tails, open fish, clean out fish, remove fish bones and even peel off the skin, the latter, I believe, aided by rapid heating of the skin with steam before removal. If there is a constant processing of fish, the cost of maintaining such automatic machines could be met and a large part if not all of the cost of the fish tanks could be offset by the cost savings of the automatic processing.
At C, is shown the feeding cart, c. The cart would travel around a circular set of tracks at the edge of the tank. It would spray the food across the tank for the fish to feed. One of the complaints of pen raised fish is that the flesh is flabby from having no exercise for salmon and tuna. The cart allows the fish to exercise by chasing their food. For slow moving fish, such as cod, the cart might move at 3-5 kilometers per hour, kph, for salmon it might move at 10-20 kph to make them run. The cart would be refilled by a hopper, h, that would move on overhead rails. There would be 2 carts, 1 would be feeding the fish while the other is refilled. As the first approaches the loading station, the second would begin moving forward while the first stops and is refilled.
If the fish are packed densely, there would be the need for frequent changes of water as fish digest protein and excrete ammonia. This would require extensive piping beneath the tanks.
By enclosing the tanks with a roof, there is no danger of bird predation and a reduced risk of pathogens moving into the water. In addition it would allow fish of different temperature regimes to be raised in one location.
By isolating the fish in tanks and raising the feed under controlled conditions, it should be possible to raise low mercury predators, such as tuna.
At I, is illustrated the movement of fish between tanks. 2 nets would be lowered into the interior tank after the exterior tank has been emptied of fish. 1 net would move forward past the tunnel connecting the 2 tanks. The tunnel doors would be opened adn a guide net, set at a diagonal across the interior tank, would be place just past the tunnel. The net behind the tunnel would be raised, and the one in front would sweep progressively around the tank, forcing the fish into the outer tank. Once this is completed, it would be repeated for the next inner tank.
Algae are the healthiest source of fish food, currently, the least expensive method of raising them is to feed them white sugar in dark spaces. That is not particularly sustainable. Algae are plants and can be raised in sunlight, they are also needed to reprocess the enormous amount of ammonia the fish would excrete.
At D, is shown one possible solution. A mandrel of metal that has a coefficient of temperature expansion greater than glass would be place on supports. An extrusion form would deposit molten glass around the mandrel. Then another section of the extrusion device would vapor deposit aluminum onto the glass tube over about 1/3 of its circumference. This aluminum would be placed on the lower side of the tube when mounted in sunlight to reflect light that has not been intercepted by the algae back into the tube to give the algae another chance to utilize it. Then another layer of glass could be deposited ocer the aluminum to protest it.
It might be necessary to have an outer slip form slide over the lower surface of the tube while being formed to prevent excessive sagging of the glass.
The mandrel would be slid horizontally after the full tube is formed and slowly cooled. When the glass has solidified, the mandrel could be withdrawn, although this would involve dragging it over the interior surface of the glass, so care would need to be taken.
The tube might have an interior diameter of 4-5 m and be 200 m long.
At E, is shown the mandrel and extruder. There are 2 supports at each end so that one can be lowered, the extruder placed and then the second support would be lowered to allow the extruder to proceed down the mandrel.
To estimate the size of the field for the tubes: 170 000 000 kg of fish X 1000 gm/kg X 4 Calories per gram of protein or carbohydrate, fat is 8 Calories, but 1 food Calorie is actually 1 kilocalorie or 1000 calories X 4 joules / calorie = 2700 X 10^12 joules per year or 7 X 10^12 joules per day. But fish need at least 1 1/2 calorie of food for each calorie of fish, = 10 X 10^12 joules /day.
Sunlight at noon directly under the solar high point, equator, is over 1 kilowatt/m2. Allow for at least 10 hours of sunlight X 0.7 to allow for the average solar elevation X 3600 seconds per hour X 0.7 to allow for cloud cover = 18 000 000 watt-seconds or joules / m2.
Dividing 10 X 10^12 by 18 X 10^6 = 550 000 m^2. However plants are not very efficient in using sunlight. Terrestrial plants do not exceed 5% conversion of solar energy into plant energy. 5% would require 20 times or 11 square kilometers.
The parts of the fish not sold, about 1/2 could be fed to other fish, that would be a 1/3 reduction in calorie needs, but the algae would be mostly fed to an intermediary such as krill or herring and that would require more food. This is what would probably kill it, the cost of all those glass tubes and the plumbing they would require.
If this could be afforded, the glass of the tubes would be cleaned every night by a robotic scrubber that would move through them with brushes that cover the entire interior surface.
F, shows the central fish tanks with arrays of glass tubes and production facilities connected to it. The fish would be moved into the separate production units immediately after harvesting.
G, shows the harvesting ring, a smaller ring at the outside.
H, shows the capture method of forcing the fish to a central conveyor belt where they are raised and stunned by electricity before moving into the processing equipment.
There is an increasing demand for fish while native stocks are being stressed by over fishing. The obvious solution is to raise fish. There are difficulties of fish parasites and disease outbreaks in close confinement when they are raised in ocean pens. An alternative is to build large enclosed fish-rearing tanks.
For 1000 m width and allowing 200 m for a center portion for early growth tanks and support equipment and facilities, there would be 16 rings. The average diameter would be about, 1000 + 200 = 1200/ 2 = 600 m for a circumference of 1800 m. With a depth of 20 m; 1800 X 20 X 20 X 16 rings =
12 000 000 cubic meters, m3. The question then becomes how tightly to pack the fish.
If the fish are stocked at 1 / 40 the volume, apparently tighter packing is possible, and one assumes that the fish double in size each year over a 3 year growth cycle, the fish would need 1 volume in year 1, 2 volumes in year 2, and 4 volumes in year 3, actually there would be somewhat more available for year 3 as the fish do not spontaneously double in size, or 4 / 7, 57%, would be harvested, so
12 000 000 X .57 / 40 = 170 000 metric tonnes of fish harvested annually. Allowing a net yield of 50% weight for fillets, = 85 000 000 kilograms of salable weight annually.
For a structure of 1000 m by 1000 m, if the construction costs are $5000 / square meter, m2, the total cost would be $5 000 000 000 ($5 billion). If financing is at 5%, the structure should last at least 50 years,so amortization could be adjusted for that period, the finance costs would be $250 000 000 /yr or $3 per kilogram of salable fish.
There was a report some 10 years ago that said fish processors in Norway were shipping fish to China for processing before returning them for sale in Norway. The claim was that shipping and processing in China cost over $1.50 / kg, while Norwegian processing cost some $3.00 / kg. As fuel prices rise, the cost of shipping rises and the total cost of shipping and processing.
Machines have been built as test equipment that can automatically; cut off fish heads and tails, open fish, clean out fish, remove fish bones and even peel off the skin, the latter, I believe, aided by rapid heating of the skin with steam before removal. If there is a constant processing of fish, the cost of maintaining such automatic machines could be met and a large part if not all of the cost of the fish tanks could be offset by the cost savings of the automatic processing.
At C, is shown the feeding cart, c. The cart would travel around a circular set of tracks at the edge of the tank. It would spray the food across the tank for the fish to feed. One of the complaints of pen raised fish is that the flesh is flabby from having no exercise for salmon and tuna. The cart allows the fish to exercise by chasing their food. For slow moving fish, such as cod, the cart might move at 3-5 kilometers per hour, kph, for salmon it might move at 10-20 kph to make them run. The cart would be refilled by a hopper, h, that would move on overhead rails. There would be 2 carts, 1 would be feeding the fish while the other is refilled. As the first approaches the loading station, the second would begin moving forward while the first stops and is refilled.
If the fish are packed densely, there would be the need for frequent changes of water as fish digest protein and excrete ammonia. This would require extensive piping beneath the tanks.
By enclosing the tanks with a roof, there is no danger of bird predation and a reduced risk of pathogens moving into the water. In addition it would allow fish of different temperature regimes to be raised in one location.
By isolating the fish in tanks and raising the feed under controlled conditions, it should be possible to raise low mercury predators, such as tuna.
At I, is illustrated the movement of fish between tanks. 2 nets would be lowered into the interior tank after the exterior tank has been emptied of fish. 1 net would move forward past the tunnel connecting the 2 tanks. The tunnel doors would be opened adn a guide net, set at a diagonal across the interior tank, would be place just past the tunnel. The net behind the tunnel would be raised, and the one in front would sweep progressively around the tank, forcing the fish into the outer tank. Once this is completed, it would be repeated for the next inner tank.
At D, is shown one possible solution. A mandrel of metal that has a coefficient of temperature expansion greater than glass would be place on supports. An extrusion form would deposit molten glass around the mandrel. Then another section of the extrusion device would vapor deposit aluminum onto the glass tube over about 1/3 of its circumference. This aluminum would be placed on the lower side of the tube when mounted in sunlight to reflect light that has not been intercepted by the algae back into the tube to give the algae another chance to utilize it. Then another layer of glass could be deposited ocer the aluminum to protest it.
It might be necessary to have an outer slip form slide over the lower surface of the tube while being formed to prevent excessive sagging of the glass.
The mandrel would be slid horizontally after the full tube is formed and slowly cooled. When the glass has solidified, the mandrel could be withdrawn, although this would involve dragging it over the interior surface of the glass, so care would need to be taken.
The tube might have an interior diameter of 4-5 m and be 200 m long.
To estimate the size of the field for the tubes: 170 000 000 kg of fish X 1000 gm/kg X 4 Calories per gram of protein or carbohydrate, fat is 8 Calories, but 1 food Calorie is actually 1 kilocalorie or 1000 calories X 4 joules / calorie = 2700 X 10^12 joules per year or 7 X 10^12 joules per day. But fish need at least 1 1/2 calorie of food for each calorie of fish, = 10 X 10^12 joules /day.
Sunlight at noon directly under the solar high point, equator, is over 1 kilowatt/m2. Allow for at least 10 hours of sunlight X 0.7 to allow for the average solar elevation X 3600 seconds per hour X 0.7 to allow for cloud cover = 18 000 000 watt-seconds or joules / m2.
Dividing 10 X 10^12 by 18 X 10^6 = 550 000 m^2. However plants are not very efficient in using sunlight. Terrestrial plants do not exceed 5% conversion of solar energy into plant energy. 5% would require 20 times or 11 square kilometers.
The parts of the fish not sold, about 1/2 could be fed to other fish, that would be a 1/3 reduction in calorie needs, but the algae would be mostly fed to an intermediary such as krill or herring and that would require more food. This is what would probably kill it, the cost of all those glass tubes and the plumbing they would require.
If this could be afforded, the glass of the tubes would be cleaned every night by a robotic scrubber that would move through them with brushes that cover the entire interior surface.
F, shows the central fish tanks with arrays of glass tubes and production facilities connected to it. The fish would be moved into the separate production units immediately after harvesting.
G, shows the harvesting ring, a smaller ring at the outside.
H, shows the capture method of forcing the fish to a central conveyor belt where they are raised and stunned by electricity before moving into the processing equipment.
Tuesday, April 10, 2012
49ers stadium
F-35 shown obsolete on previous posts
The San Francisco 49ers, an NFL, american professional football, franchise long argued over how and where to build a new stadium, I would suggest floating it. Their current stadium is located at Candlestick Point, directly along San Francisco Bay, so access to the water is relatively easy.
The idea is to build a massive monolithic platform, a giant barge, out of concrete and guild the parking structure and stadium on top of it. In order to recover the cost of construction, buildings would be built on top as well to produce additional revenue, A, B. The platform might be 2000 ft by
10 000 ft.
Concrete is weak in tension so post tensioning, placing wires in the concrete and tightening them to produce a compressive stress which under tension does not produce net tension, would be needed to overcome the stresses produced by waves. 2 dimensional post tensioning, as D, has been used. For the stresses ina floating platform, 3 dimensional post tensioning , as E, must be used. For 2 dimesions, the wires can be laid out and the concrete poured over them before i sets and the wires can be tensioned. For 3 dimensions, the vertical wires would have to be held on a reel with 1 end attached to an anchor plate, before the horizontal wires are laid and the concrete poured, F. The lowest level of horizontal layer could be pre-molded and cured before being set as blocks with lead wires placed in the4 wire guideways. The lead wires would be connected as each block is placed. When all the blocks have been placed the tensioning wire would be attached to the lead wire string and the lead wires pulled through placing the tensioning wires.
For forming the concrete, large blocks of expanded concrete could be used as molds. Expanded concrete is concrete with a lot of little air holes in it. It is similar to styrofoam. Normal concrete weighs about 150 pounds per cubic foot, pcf; expanded concrete can weigh as little as 10 pcf. Sea water weighs 64 pcf. The expanded blocks, when placed, with spaces between for pouring the structural concrete, would render the entire platform unsinkable. Even if the platform broke into pieces each piece would float as the platform would weigh less than sea water and the expanded concrete would prevent sea water from flooding and sinking the structure. In addition the expanded concrete would prevent buckling of the structural concrete walls and floors allowing the concrete to achieve its maximal compressive stress.
At I, is shown a slightly different construction method. The molded blocks are used as the lowest base but an additional layer of concrete which would be post tensioned would be poured on top of them before the expanded concrete blocks are placed.
Where there is automobile parking, it might be a good idea to place expanded concrete above the structural concrete but below the actual parking surface. That would allow for energy absorbtion in the expanded concrete in the event of a car bomb. The creation of a a sacrificial surface such as that would prevent damage to the structure, which would be very difficult to repair, H.
At G is shown the possibility of building a convention center and exhibition space as an additional amenity. The roof could span 1000 ft with a tied arch, a steel arch that has an additional continuous steel beam along its lower edge to counteract the reaction forces of the toes of the arch. To the sides of the central space could bre additional conference rooms, offices and smaller group rooms.
Over the parking areas, walkways could be built, they would provide a public access amenity. This would be necessary to gain approval for the construction. The walkways would be 100 ft wide to allow for cafes restaurants and shops. They would be wide enough to also allow for the installation of basketball and tennis courts. Across the walkway, J and L, a, there might be 4 supports for redundancy. Along the walkway, K and L, b, the spacing of the column groups could be 50 ft to allow for vehicle parking nad access lanes.
At M, is shown the floating structure connected to shore by arched bridges. By floating the structure, it is immune to earthquakes, although the bridges and water, electric, gas and sewer lines could be damaged.
At lower right is illustrated some consideration of wave action and bending stresses. The Golden Gate restricts energy input form the Pacific Ocean and the large size of the4 bay dissipates the energy that does enter. Waves produced by wind blowing over the bay are limited by the dimensions of the bay itself.
Allowing for a 1000 ft long wave, a wave of 14 second period, which would be unlikely to ever be seen in the bay, the half-wave length would be 500 feet. d could represent the distance between the centroid of the lower quarter wave and the upper 1/4 wave, maybe 400 ft. For a sine wave, the area of water would be about 2/3 of the 1/4 wave length X wave amplitude, 1/2 wave height. If the platform is 40 ft thick and the upper and lower concrete surfaces are 3 ft thick, for an allowable concrete strength of 3000 pounds per square inch, psi, 430 000 lbs/ foot square, psf, the maximum moment would be 40 X 3 X 430 000 = 52 000 000 pound feet. For d = 400, 130 000 lbs of force over 250 ft, 1/4 of 1000 ft, = 520 lbs per foot. But since the area is about 2/3, 1 1/2 X 520 = 780 lbs /ft.; Divided by 64, weight of seawater = 8 ft. X 2 to allow for both upper and lower waves portions, = 16 ft larger than any wave likely to be encountered in San Francisco Bay.
The platform would have 2 X 3 feet of concrete for the upper and lower surfaces + the blocks underneath of maybe 2 ft for a total of 8 feet. In addition there must be vertical structural walls, maybe 2 feet thick every 100 X 100 feet. That would be 100 + 110 = 200 X 40 X 2 = 16 000, divided by 100 X 100 = 1.6 feet 8 + 1.6 = 9.6. It takes 2.5 feet of water to displace 1 ft concrete, 9.6 X 2.5 = 24 ft. In addition ther is the expanded concrete 40 X 10 / 64 = 6.5 feet. The total is 24 + 6.5 = 30.5 plus the weight of buildings. Allowing 4 feet of concrete, which should be about 4 floors of building, that would require an additional 10 ft, total = 41 feet displacement.
If the buildings equal 4 floors, they would be concentrated so that 30 floors would be built over 1/8 of the structure or 40 floors over 1/10.
#0 feet of water = 1 ton or 1/2 cubic yard of concrete. ! cubic yard of concrete costs about $150, labor adds a lot more cost. If the cost is $1000 per square foot, the average for each floor of building would be $250/ square foot. But not all the space is sellable, hallways elevator shafts, so the cost might be $330/ square foot. With construction the total might be $700 / square foot. For a 2000 square foot apartment, fairly large, the cost would be $1 400 000. There would need to be 2 000 X
10 000 X 4 X 3/4 / 2000 = 30 000 apartments. San Francisco has a population of about 600 000 or
240 000 dwellings. In addition, some buildings could be used as hotels or office buildings, it might actually be affordable.
To build the platform, a series of pipes in a herringbone pattern would be emplaced below the depth necessary to float the platform, N, O. Then steel sheet piling would be driven to form a rough rectangle. The area enclosed would have sand pumped in to fill above the high tide line. The pipes could pump out water to consolidate the sand. The loer blocks would be placed and the platform poured and allowed to set. The sheet piling would be removed and water would be puped through the pipes to undercut the sand until the platform floats The platform would then be towed into position. The sand could then be restored to its original condition.
One additional point is that the platform would block sunlight,killing sea grass where it is anchored. There might also be a deficit of oxygen under the platform, so air might have to be pumped to prevent fish kills.
The other question is what the life time of the platform would be, 50 years, at least should be obtainable.
The San Francisco 49ers, an NFL, american professional football, franchise long argued over how and where to build a new stadium, I would suggest floating it. Their current stadium is located at Candlestick Point, directly along San Francisco Bay, so access to the water is relatively easy.
10 000 ft.
For forming the concrete, large blocks of expanded concrete could be used as molds. Expanded concrete is concrete with a lot of little air holes in it. It is similar to styrofoam. Normal concrete weighs about 150 pounds per cubic foot, pcf; expanded concrete can weigh as little as 10 pcf. Sea water weighs 64 pcf. The expanded blocks, when placed, with spaces between for pouring the structural concrete, would render the entire platform unsinkable. Even if the platform broke into pieces each piece would float as the platform would weigh less than sea water and the expanded concrete would prevent sea water from flooding and sinking the structure. In addition the expanded concrete would prevent buckling of the structural concrete walls and floors allowing the concrete to achieve its maximal compressive stress.
Where there is automobile parking, it might be a good idea to place expanded concrete above the structural concrete but below the actual parking surface. That would allow for energy absorbtion in the expanded concrete in the event of a car bomb. The creation of a a sacrificial surface such as that would prevent damage to the structure, which would be very difficult to repair, H.
At G is shown the possibility of building a convention center and exhibition space as an additional amenity. The roof could span 1000 ft with a tied arch, a steel arch that has an additional continuous steel beam along its lower edge to counteract the reaction forces of the toes of the arch. To the sides of the central space could bre additional conference rooms, offices and smaller group rooms.
At M, is shown the floating structure connected to shore by arched bridges. By floating the structure, it is immune to earthquakes, although the bridges and water, electric, gas and sewer lines could be damaged.
At lower right is illustrated some consideration of wave action and bending stresses. The Golden Gate restricts energy input form the Pacific Ocean and the large size of the4 bay dissipates the energy that does enter. Waves produced by wind blowing over the bay are limited by the dimensions of the bay itself.
Allowing for a 1000 ft long wave, a wave of 14 second period, which would be unlikely to ever be seen in the bay, the half-wave length would be 500 feet. d could represent the distance between the centroid of the lower quarter wave and the upper 1/4 wave, maybe 400 ft. For a sine wave, the area of water would be about 2/3 of the 1/4 wave length X wave amplitude, 1/2 wave height. If the platform is 40 ft thick and the upper and lower concrete surfaces are 3 ft thick, for an allowable concrete strength of 3000 pounds per square inch, psi, 430 000 lbs/ foot square, psf, the maximum moment would be 40 X 3 X 430 000 = 52 000 000 pound feet. For d = 400, 130 000 lbs of force over 250 ft, 1/4 of 1000 ft, = 520 lbs per foot. But since the area is about 2/3, 1 1/2 X 520 = 780 lbs /ft.; Divided by 64, weight of seawater = 8 ft. X 2 to allow for both upper and lower waves portions, = 16 ft larger than any wave likely to be encountered in San Francisco Bay.
The platform would have 2 X 3 feet of concrete for the upper and lower surfaces + the blocks underneath of maybe 2 ft for a total of 8 feet. In addition there must be vertical structural walls, maybe 2 feet thick every 100 X 100 feet. That would be 100 + 110 = 200 X 40 X 2 = 16 000, divided by 100 X 100 = 1.6 feet 8 + 1.6 = 9.6. It takes 2.5 feet of water to displace 1 ft concrete, 9.6 X 2.5 = 24 ft. In addition ther is the expanded concrete 40 X 10 / 64 = 6.5 feet. The total is 24 + 6.5 = 30.5 plus the weight of buildings. Allowing 4 feet of concrete, which should be about 4 floors of building, that would require an additional 10 ft, total = 41 feet displacement.
If the buildings equal 4 floors, they would be concentrated so that 30 floors would be built over 1/8 of the structure or 40 floors over 1/10.
#0 feet of water = 1 ton or 1/2 cubic yard of concrete. ! cubic yard of concrete costs about $150, labor adds a lot more cost. If the cost is $1000 per square foot, the average for each floor of building would be $250/ square foot. But not all the space is sellable, hallways elevator shafts, so the cost might be $330/ square foot. With construction the total might be $700 / square foot. For a 2000 square foot apartment, fairly large, the cost would be $1 400 000. There would need to be 2 000 X
10 000 X 4 X 3/4 / 2000 = 30 000 apartments. San Francisco has a population of about 600 000 or
240 000 dwellings. In addition, some buildings could be used as hotels or office buildings, it might actually be affordable.
One additional point is that the platform would block sunlight,killing sea grass where it is anchored. There might also be a deficit of oxygen under the platform, so air might have to be pumped to prevent fish kills.
The other question is what the life time of the platform would be, 50 years, at least should be obtainable.
Saturday, April 7, 2012
No land mines
F-35 shown obsolete on previous posts
Anti-personnel land mines are notoriously useless, they have at best barely slowed an attacking force, although they do produce gruesome injuries. The purpose of any localized defense is to slow an attacking force long enough for mortars and artillery to be aimed and additional forces to be deployed. In U.S. doctrine, mine fields are only used with an overwatch, personnel deployed immediately behind them. Russians and Chinese bury and abandon mines to impede and discourage movement.
In World War I, the British developed what they called the Livens projector. It was a pipe section with a steel plate welded across one end. In side of this pipe were placed a propellant charge and a metal canister containing poison gas. A shallow hole would be dug, the projector placed in it at a desirable angle and the apparatus would be used as a short range mortar to throw the canister and gas to the opponents trench lines.
A more modern version of this could be built with cluster munitions, A. It would be better for the cluster bombs to be deployed as D rather than C, having more of a horizontal to left and right rather than elongated in depth, the attacking force would be deployed effectively horizontally and the munitions would want a similar spread to cover them. Infantry tend to be useless when firing rifles at more than one hundred meters, so covering relatively short range fire over a horizontal distance left and right is more important than firing at greater range, at least for stopping an immediate attack.
In order to achieve this spread the casing would have an oval shape,similar to D, and a cone would be placed over the propellant, inside the bombs as at A. That should cause a wider spread when fired. The maximum range desired would be no more than 200 meters. There is a ballistic formula neglecting air drag; distance, s = velocity squared / gravity when fired at the angle of 45, which achieves maximal range. For 200 m, g = 10 m/s2, v = 45 m/s, a very low velocity and the projector walls can be fairly thin.
For the bomblets, assume an explosive content of 200 grams and a steel jacket of 100 grams. Thee is a normalized distance, a product of dimensional analysis for explosives. It is the energy of the explosive divided by atmospheric pressure and then the third root of the quotient being taken. For 200 gram of explosive, assuming an explosive value of about 4.8 Mega joules per kilogram, the normalized distance would be a little over 2 meters. At sea level, at one half standard distance there are 100% fatalities; at 3/4 standard distance lungs collapse. The bomblets would explode on the ground, so the explosive force would be peak at ankle height, the distance is measured form the actual point of the explosion. With the metal fragments and the explosion, it might be disruptive out to about meters radius or about 50 square meters.
The question then becomes centered on how heavy to make the loaded projector. If 300 bomblets of 300grams each were loaded, they would mass 90 kilograms, all up it would mass 120-150 kg. It could ber made smaller, but it would still be movable by a small group of personnel. 300 bomblets at 50 m2 each would cover 15 000 m2, or an ellipse of 100 meters by 200 meters.
The projectors would be placed just in front of the defensive position, that way short falls would not land on the defenders. They would be dug into the ground with an angle appropriate for the desired range, B. They could be made in 2 varieties; one with the bomblets detonating immediately upon contact with the ground, and another with delay fuses that would explode in sequence like popcorn. The first would be fired to stop the progress of the attack and then the second would be fired to inhibit reorganization of the attack.
If the projectors are not used, their safety switches can be reset and they can be carried off to be reused. I do not believe that any minefield ever inflicted more than 5% casualties on an attacking force, the projectors would be more effective at stopping, or at least delaying and inhibiting an attack.
This system would eliminate the problems of the inevitable casualties associated with laying one's own minefield. It does use cluster bomblets which many countries are moving away from.
Thursday, April 5, 2012
Sea mine
F-35 shown obsolete on previous posts
The desirable characteristic of a sea mine is its ability to actually strike a ship. One way to accomplish this is to make the mine actually hunt the target ship.
One way of achieving this goal is to build an inflatable mine. The mine would come folded in a bag, C. The bag would reduce the loss of plasticizer, chemicals added to the plastic material to keep it flexible,
which can be leached out with exposure to water. The bag will also help to hide the deflated mine. For a sand bottom, the bag would have sand glued onto its surface to mimic the bottom; for a mud bottom, the bag would be coated with foam rubber which would look like mud. The bag would have a bleed hole to force any air out when it descends to the bottom. When the mine inflates, the bag would rupture and the mine would emerge.
To inflate the mine, nitrogen under pressure would be stored in tanks.
If the cone diameter is 1.5 m and the tail is made with a length to diameter ratio of 6, then the volume of the mine would be 1/2 X 4/3 X pi X 0.75 X 0.75 X 0.75 (1/2 of a sphere) for the rounded top + 1/3 X pi X 0.75 X 0.75 X 6 X 1.5 for the cone = 0.88 + 5.3 = 6.2 cubic meters, m3, for a lifting force of 6.2 metric tonnes
X gravity. At a depth of 1000 m, the pressure is 100 atmospheres or 10 Mega pascals. Pressure cylinders or balls are built commercially to withstand at least 400 atmospheres. Allowing 500 atmospheres pressure,
50 000 000 Mega-pascals, there would need to be 1.24 m3 of gas to inflate at 1000 m. A ball of 1m diameter would have a cross section of 0.78 m2 for a pressure of 50 000 000 X 0.78 = 39 000 000 Newtons. Aluminum could withstand 300 Mega pascals or more. The circumference of the ball would be 3.14 m for 39 000 000 / 3.14 = 12 500 000 N/m. That would require a thickness of 12 500 000 / 300 000 000 = 0.042 m. The area of the ball would be 4 X pi X 0.5 X 0.5 = 3.14 m2. X 0.042 = 0.133 m3, or, with aluminum weighing 2.5 tonnes / m3, a weight of 0.333 tonnes. The volume would be about 0.5 m3, so 3 would be needed to inflate. 3 would be external to the mine for initial inflation, another 1 would be carried inside the mine for additional equalization. The 3 external would be placed in the bag.
The mine would be inflated and the bag ruptured and discarded. The initial trigger would be acoustic and the mine would track acoustically. Upon inflation, a heat source would raise the internal temperature to the curing point of the plastic, making it hard and the mine rigid. There is a danger that the heating could damage the electronics, so they would have to be insulated and the interior ball would release nitrogen to coll the electronics and to make up the losses in nitrogen. The curing temperature would be about 80 C, or 350 K. The sea water would be about 0 C, so about 1/4 of the gas would expand and be released through a pressure equalizing valve at the back end of the mine. The nitrogen used to cool the electronics would replace this as the mine cools. As the mine rises, additional gas would be vented as their is a small limit to the differential pressure form inside to outside that the mine wall could withstand. The plastic curing would not be perfect, but it would only need to be good enough to allow maneuvering. The inflating balls would be cut loose once inflating has been completed.
The maximum moment sustainable at the ring of the top curve would be; pi X 0.75 X 0.75 X thickness of skin X maximum allowable force of skin. Allowing 7 Mega pascals for strength, a fairly low value and a skin thickness of 0.005 m; maximum moment would be 60 000 N-m. If control surfaces are 8 m from the ring, a maximum control force of 7 500 N could be obtained. However, thin walled buckling would greatly reduce this. If the surface of the mine is not made smooth, but with a series of curved ridges as at D, the point of thin walled buckling would be delayed. There appears to be enough strength for maneuvering.
The skin area would be; 2 X pi X 0.75 X 0.75 + pi X 0.75 X 0.75 X 1/2 X 9 = 3.5 + 7.7 = 11.2 m2. For a plastic density of 1.6 tonnes / m3 and a thickness of 0.005 m = 0.09 tonnes. Allowing 0.5 tonnes for explosives + 0.33 for internal nitrogen ball + 0.09 = 0.92 or maybe 1 tonne all up. With 6.2 tonnes of lift there is a net of 5.2 tonnes or the mine would have a thrust to weight ratio of 1 at an angle of about 12% from the horizontal, allowing it to chase down ships. This is for near surface. At 6.2 m^3, there would be about 280 standard volumes, each standard volume is 22.4 liters. The molecular weight of nitrogen is 28, therefore the nitrogen would mass 8 kg for each atmosphere. At 1000 m, ther would be 100 atmospheres or 800 kg nitrogen mass.
The terminal guidance would be optical, attacking the mass of the ship. The conical shape would cause some focusing of the blast shock waves off of the water cone and upwards into the hull of the ship, B. The cone shape is also highly streamlined and should allow speeds of 50 knots,
The mine would probably require a minimum depth of water of at least 200 m to function.
The mine would appear to be debris when lying in the bag, making it difficult to detect. The nitrogen balls could have plastic outer coverings to disguise their shapes for incresed difficulty in identification.
The desirable characteristic of a sea mine is its ability to actually strike a ship. One way to accomplish this is to make the mine actually hunt the target ship.
which can be leached out with exposure to water. The bag will also help to hide the deflated mine. For a sand bottom, the bag would have sand glued onto its surface to mimic the bottom; for a mud bottom, the bag would be coated with foam rubber which would look like mud. The bag would have a bleed hole to force any air out when it descends to the bottom. When the mine inflates, the bag would rupture and the mine would emerge.
To inflate the mine, nitrogen under pressure would be stored in tanks.
If the cone diameter is 1.5 m and the tail is made with a length to diameter ratio of 6, then the volume of the mine would be 1/2 X 4/3 X pi X 0.75 X 0.75 X 0.75 (1/2 of a sphere) for the rounded top + 1/3 X pi X 0.75 X 0.75 X 6 X 1.5 for the cone = 0.88 + 5.3 = 6.2 cubic meters, m3, for a lifting force of 6.2 metric tonnes
X gravity. At a depth of 1000 m, the pressure is 100 atmospheres or 10 Mega pascals. Pressure cylinders or balls are built commercially to withstand at least 400 atmospheres. Allowing 500 atmospheres pressure,
50 000 000 Mega-pascals, there would need to be 1.24 m3 of gas to inflate at 1000 m. A ball of 1m diameter would have a cross section of 0.78 m2 for a pressure of 50 000 000 X 0.78 = 39 000 000 Newtons. Aluminum could withstand 300 Mega pascals or more. The circumference of the ball would be 3.14 m for 39 000 000 / 3.14 = 12 500 000 N/m. That would require a thickness of 12 500 000 / 300 000 000 = 0.042 m. The area of the ball would be 4 X pi X 0.5 X 0.5 = 3.14 m2. X 0.042 = 0.133 m3, or, with aluminum weighing 2.5 tonnes / m3, a weight of 0.333 tonnes. The volume would be about 0.5 m3, so 3 would be needed to inflate. 3 would be external to the mine for initial inflation, another 1 would be carried inside the mine for additional equalization. The 3 external would be placed in the bag.
The mine would be inflated and the bag ruptured and discarded. The initial trigger would be acoustic and the mine would track acoustically. Upon inflation, a heat source would raise the internal temperature to the curing point of the plastic, making it hard and the mine rigid. There is a danger that the heating could damage the electronics, so they would have to be insulated and the interior ball would release nitrogen to coll the electronics and to make up the losses in nitrogen. The curing temperature would be about 80 C, or 350 K. The sea water would be about 0 C, so about 1/4 of the gas would expand and be released through a pressure equalizing valve at the back end of the mine. The nitrogen used to cool the electronics would replace this as the mine cools. As the mine rises, additional gas would be vented as their is a small limit to the differential pressure form inside to outside that the mine wall could withstand. The plastic curing would not be perfect, but it would only need to be good enough to allow maneuvering. The inflating balls would be cut loose once inflating has been completed.
The maximum moment sustainable at the ring of the top curve would be; pi X 0.75 X 0.75 X thickness of skin X maximum allowable force of skin. Allowing 7 Mega pascals for strength, a fairly low value and a skin thickness of 0.005 m; maximum moment would be 60 000 N-m. If control surfaces are 8 m from the ring, a maximum control force of 7 500 N could be obtained. However, thin walled buckling would greatly reduce this. If the surface of the mine is not made smooth, but with a series of curved ridges as at D, the point of thin walled buckling would be delayed. There appears to be enough strength for maneuvering.
The skin area would be; 2 X pi X 0.75 X 0.75 + pi X 0.75 X 0.75 X 1/2 X 9 = 3.5 + 7.7 = 11.2 m2. For a plastic density of 1.6 tonnes / m3 and a thickness of 0.005 m = 0.09 tonnes. Allowing 0.5 tonnes for explosives + 0.33 for internal nitrogen ball + 0.09 = 0.92 or maybe 1 tonne all up. With 6.2 tonnes of lift there is a net of 5.2 tonnes or the mine would have a thrust to weight ratio of 1 at an angle of about 12% from the horizontal, allowing it to chase down ships. This is for near surface. At 6.2 m^3, there would be about 280 standard volumes, each standard volume is 22.4 liters. The molecular weight of nitrogen is 28, therefore the nitrogen would mass 8 kg for each atmosphere. At 1000 m, ther would be 100 atmospheres or 800 kg nitrogen mass.
The terminal guidance would be optical, attacking the mass of the ship. The conical shape would cause some focusing of the blast shock waves off of the water cone and upwards into the hull of the ship, B. The cone shape is also highly streamlined and should allow speeds of 50 knots,
The mine would probably require a minimum depth of water of at least 200 m to function.
The mine would appear to be debris when lying in the bag, making it difficult to detect. The nitrogen balls could have plastic outer coverings to disguise their shapes for incresed difficulty in identification.
Tuesday, April 3, 2012
Paul Allen's rocket plane mistake
F-35 shown obsolete in previous posts
Paul Allen got together with Burt Rutan to build a plane to carry a rocket aloft for space launch they got it very wrong. I actually did a thing called Space Launch about two weeks before they announced their exercise in failed engineering.
Fo0r reasons which I am sure they think are reasonable, they have decided to build an aircraft with two full sized bodies and place the rocket on a wing section connecting the two, B. This achieves the truly impressive result of increasing weight, increasing the wetted surface and making the entire aircraft heavier and less maneuverable as well as more expensive. Any reasonable observer would have to conclude that that level of incompetence could not be easily achieved, it would take actual work to equal that degree of failure.
The correct design procedure is to build a single aircraft body and place the rocket on top, A. The cockpit would constitute a separate capsule, C. The cockpit would be on a ring mount that would allow it to rotate from a vertical to an inverted position. This can be achieved because the aircraft can be built as fly-by-wire, all of the control inputs are electrical so the transmission of signals from the cockpit to control surfaces could be by electrical contact at the ring mount, radio signals across the gap from cockpit capsule to fuselage, by laser signal across the same gap or by mounting a flexible wire bundle from the fuselage to the cockpit for signal transmission.
The aircraft flies to 10 000 ft (3000 m) and rolls inverted. A smooth, coordinated roll loads the airframe barely above 1 g, virtually the same as straight line flight. There is no danger of overstressing the structure. The cockpit capsule is then rotated 180 degrees returning the pilots to an upright vertical position. It would be in position G. In this position the rocket can be smoothly dropped. The dual tail allow the rocket to extend back further along the fuselage and ensures that there will be a smooth flow of air over the vertical stabilizers after rocket separation. A single tail would suffer some degree of flow disruption as the rocket falls and the body of the rocket blocks and disrupts the airflow to some extent.
The cockpit capsule could be built with 2 flight positions like a Gemini capsule or 3 positions like an Apollo capsule if an additional crew member is felt useful for preparing the rocket for launch. From the front end of the capsule an escape tower of a a pole structure with rocket motors mounted at the end would enable the crew to separate tin the event of a casualty to the aircraft.
The entire front end could be built into a rotating section, D, is desired. A crew of up to 8 could be accommodated if additional personnel were needed, although I would not necessarily recommend building that.
If the rocket were to be used for manned launches, the crew capsule could also be made to rotate on the rocket mounting, although there would be a weight penalty of several hundred pounds.
To place the rocket on top of the airplane, a tower could be built with an extended arm which would be attached to the rocket carrier, E. Cables would be used to provide the lifting force. The tower would have 2 legs to allow th front of the aircraft to be moved under the arm, carrier and rocket for placement of the rocket. Another method would be to lift the rocket on a giant forklift, F.
the forklift would be built with its supports spaced far enough apart the one could be in front of the wing and the second in back. It would approach the aircraft from the side.
By having a single aircraft that rolls inverted, the aircraft would be lighter and less expensive, allowing for a larger rocket to be carried or a higher altitude to be reached before separation.
If anyone sees Paul Allen, tell him he is wasting hi money, but he has plenty and he won't miss it. If you meeet Burt Rutan, tell him he botched the engineering.
Paul Allen got together with Burt Rutan to build a plane to carry a rocket aloft for space launch they got it very wrong. I actually did a thing called Space Launch about two weeks before they announced their exercise in failed engineering.
The correct design procedure is to build a single aircraft body and place the rocket on top, A. The cockpit would constitute a separate capsule, C. The cockpit would be on a ring mount that would allow it to rotate from a vertical to an inverted position. This can be achieved because the aircraft can be built as fly-by-wire, all of the control inputs are electrical so the transmission of signals from the cockpit to control surfaces could be by electrical contact at the ring mount, radio signals across the gap from cockpit capsule to fuselage, by laser signal across the same gap or by mounting a flexible wire bundle from the fuselage to the cockpit for signal transmission.
The aircraft flies to 10 000 ft (3000 m) and rolls inverted. A smooth, coordinated roll loads the airframe barely above 1 g, virtually the same as straight line flight. There is no danger of overstressing the structure. The cockpit capsule is then rotated 180 degrees returning the pilots to an upright vertical position. It would be in position G. In this position the rocket can be smoothly dropped. The dual tail allow the rocket to extend back further along the fuselage and ensures that there will be a smooth flow of air over the vertical stabilizers after rocket separation. A single tail would suffer some degree of flow disruption as the rocket falls and the body of the rocket blocks and disrupts the airflow to some extent.
The cockpit capsule could be built with 2 flight positions like a Gemini capsule or 3 positions like an Apollo capsule if an additional crew member is felt useful for preparing the rocket for launch. From the front end of the capsule an escape tower of a a pole structure with rocket motors mounted at the end would enable the crew to separate tin the event of a casualty to the aircraft.
The entire front end could be built into a rotating section, D, is desired. A crew of up to 8 could be accommodated if additional personnel were needed, although I would not necessarily recommend building that.
If the rocket were to be used for manned launches, the crew capsule could also be made to rotate on the rocket mounting, although there would be a weight penalty of several hundred pounds.
To place the rocket on top of the airplane, a tower could be built with an extended arm which would be attached to the rocket carrier, E. Cables would be used to provide the lifting force. The tower would have 2 legs to allow th front of the aircraft to be moved under the arm, carrier and rocket for placement of the rocket. Another method would be to lift the rocket on a giant forklift, F.
the forklift would be built with its supports spaced far enough apart the one could be in front of the wing and the second in back. It would approach the aircraft from the side.
By having a single aircraft that rolls inverted, the aircraft would be lighter and less expensive, allowing for a larger rocket to be carried or a higher altitude to be reached before separation.
If anyone sees Paul Allen, tell him he is wasting hi money, but he has plenty and he won't miss it. If you meeet Burt Rutan, tell him he botched the engineering.
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