New mechanism of lift generation that I think.

     First, let's look at how the “object: 2D” with an elliptical cross section as shown below moves through the air. The object moving to the left, it is equal to the condition that the object receives a flow of air from the left for convenience. 

"Principle 1” 

     The force F is generated by the pressure difference between the high pressure region a (red) formed by compressing air on the front surface of an object moving in the air and the low pressure region b (blue) formed by stretching the air on the rear surface.

 "Principle 2”

     The flow from the high pressure area a on the front side of the object to the low pressure area b on the back side is faster than the moving speed, and when the fast flow c bends, the forward and upward force Fc is generated, and Fd is generated by fast flow d, but the vertical component is offset and the flow component becomes a positive force.

-Therefore, no lift is generated in the vertical direction on this object, and only drag (F + viscous resistance-flow direction component of FcFd) acts.    

     Next, replace the "object" with a wing with an angle of attack.

 "Principle 1” 

     Force F is generated by the pressure difference between the high pressure region a (red) formed by compressing air on the front surface (almost the lower surface) of the wing and the low pressure region b (blue) formed by stretching the air on the rear surface (almost the upper surface). increase.

 "Principle 2” 

      The flow c from the high pressure area a on the front surface of the wing to the low pressure area b on the rear surface is faster than the moving speed, and when the fast flow c bends, the reaction force that bends the flow c on the upper surface causes a forward and upward force Fc . Then, the flow d generates a forward and downward force Fd. The flow direction components of Fc and Fd are positive forces.

-Therefore, only vertical lift (total of vertical components of F, F c, and Fd) and drag (F + viscous resistance-flow direction component of FcFd) act on this wing.

      The symbols in the two figures, a to d, F, Fc, and Fd have same meanings.      　

At this time, 

1)The magnitude of the change of air pressure between front and back the object is proportional to the moving speed, and changes one atmospheric pressure when the object moves sound velocity on the surface confront directly to the flowing direction. (At 15 ℃ 1atm.) 

2)The pressure difference of air on the wing surface is eliminated at the speed of sound, but if it continues to move, a pressure difference will continue to be generated on the surface of the wing. 

3)The point where the air splits up and down in front of the wing is at the center of the projected height in the direction of travel of the wing. 

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     The mechanism of lift generation in my opinion has been described above. The details including the experimental results that led to this theory are described on another pages in home. 

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