So there is a heat exchanger, the AC evaporator, and it is not an added component. This is requiring the entire AC system where that was not a given in the original post. But if no AC, you do need to adjust the temperature of the pressurization air...Pressurized piston aircraft I am familiar with (but been retired for 18 years) don't use a heat exchanger. Pressure ratio is low enough that air conditioning is enough. P210 did use a crude exhaust to bleed air heat exchanger for heating. Twins used combustion heater. Turbines use a heat exchanger with A/C or an ACM.
And the differential is what matters. By your reasoning I could say that my Jodel had 14.7 PSI in it.The pressure inside the balloon is roughly 14.7 psi. The pressure differential between the inside of the balloon and the outside (at STP) will be less than 0.5 psi.
The 210's system ran the cabin air from the turbo, through the sonic valve (which generates a sonic pressure wave to act as an increasing restriction to the air as its velocity increases, and the pressure drop of the air cools it some), through the heat exhanger (a little radiator) and into the cabin. The exchanger was in a box with a valving mechanism to duct either heated air from around the exhaust system (just like the usual cabin heat system) through it, or cold air from an air inlet in the front of the cowl. The airplane I worked on also had an aftermarket airconditioning system, with the usual compressor and evaporator and condenser exchangers. It was used mostly on the ground. It's weight was not insignificant.So there is a heat exchanger, the AC evaporator, and it is not an added component. This is requiring the entire AC system where that was not a given in the original post. But if no AC, you do need to adjust the temperature of the pressurization air...
Designing a pressurized fuselage is feasible. However my suggestion is: if the designer has little or no experience evaluating fatigue and crack propagation (fault tolerant pressure vessel), move away from aluminum. Aluminum is light, it can easily be bent, folded, stretched and riveted but it is a nightmare when it comes to crack propagation. Go for a composite vessel, pressure test it through may be some hundred cycles and you are good to go. Main manufacturers are doing this: 787 (carbon), A380 (glare), A350 (carbon), etc. but remember that pressurization stresses happen simultaneously with gust, maneuver stresses. Another suggestion: programmable outflow valves are immensely complex. Use simpler, redundant mechanical fixed-differential relief valves instead. You will also need a negative-pressure relief.
Depends on what you mean by "homebuilder", or "solo". Burt Rutan's Catbird and Boomerang were designed for pressurization, although they've never been tested or flown pressurized. But they both were Burt's private aircraft - not kits, and only one of each was built. Clearly, they were not SUCCESSFUL pressurized aircraft, as they were never pressurized, but I don't think that was the question .I don't think any solo homebuilder has ever built a pressurized Homebuilt?
Well, that's odd never testing the pressurization. I guess if he built them with no intention of selling the design they were "Homebuilt". Apparently not much demand for pressurized anyway.Clearly, they were not SUCCESSFUL pressurized aircraft, as they were never pressurized, but I don't think that was the question
That'll buff out.Some light reading on pressurized aircraft systems and design... NOT a trivial subject...
Cessna Training ~ Single Engine/Light Twin Pressurization ~ Student Workbook
Aircraft Pressurization - An Environmental Control System, AEM 617, Andrew Treadway
Control of Cabin Pressure - Aircraft Pressurization Systems
Aircraft systems and components introduction; description; principles; fundamentals; operating procedures; technical procedures; schematic diagrams;www.aircraftsystemstech.com
AC 25-20 PRESSURIZATION, VENTILATION AND OXYGEN SYSTEMS ASSESSMENT FOR SUBSONIC FLIGHT INCLUDING HIGH ALTITUDE OPERATION
What happens due to gross-over-pressurization during a ground-run test... just after Depot maintenance, prior to delivery...1999... the energy of pressurized/contained-air [gas] has-to-be-seen to be believed...
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