Liquid Air Plane

As I am studying the possibilities of liquid air, I thought of a liquid air powered VTOL plane. The goal is to come up with an alternative to electric powered planes. It wouldn’t be a replacement for the conventional plane for long distances.

The plane would have a narrow body (4 seats per row) and long tubular form. It would have two wings in the front and 2 wings at its back. This would allow more even lifting of the body and reduce the weight of each wing section. Long design due to narrow body would increase the distance between the wings to reduce turbulence at the back wings. Each wing section would accommodate four gas propulsion engines. The liquified air when evaporates expends 700 times of its initial volume. Unlike rockets that travel in vacuum, the lift generated by multiple wings would reduce plane’s thrust requirement during cruise. Only during takeoff and landing the gas consumption would be very high. Another advantage of the liquified air propulsion is the consumption of air which reduces the weight of the plane during cruise, this is not the case with battery powered planes.

Each wing section of the plane will have three stacked wings to increase the lift. The wings would have much thinner profile compared to turbofan plane wings. This would result in same drag but three times more lift. Only the sections connected to the body of the plane would have thicker profile because they would be carrying the plane. The gas propulsion engines would be attached close to the body of the plane to reduce the weight of the wings and reduce tension on the wings. The exhaust temperature would be the same as the ambient temperature. This would allow close placement of the engines and reduce the weight and cost of the engine.

The wings including the engines will rotate ninety degrees to allow VTOL. The wings will be rotated using the pressurized air. Therefore, no need for bulky motors and power electronics. This rotatability will also negate the need for ailerons, flaps and spoilers. There would be no mechanical parts on the wings beyond the engine section which allows them to be made thinner and lighter.  The vertical support of the stacked wings will also negate the need for vertical stabilizers. There would be no rudder as well. The tail section will have an exhaust vent that has wind turbine inside. This will generate the electricity for the plane. The fast response of this design will reduce the need for bulky batteries as well.

Almost silent propulsion of this plane would allow it to fly at much lower altitudes than the conventional planes. Allowing higher temperature difference between the liquid and the ambient air. The lift of air would also be high at lower altitudes, but the drag would also be high. More importantly this plane compared to electric planes requires no batteries, no brushless motors and power electronics that have exported materials in them. They would be simply build from a high-grade aluminum alloy.