lördag 15 september 2012

AIAA Defends Old Incorrect Theory of Flight 4

                                   Incorrect pressure distribution at trailing edge.

Let us see how the Old Theory of Flight, defended by AIAA in its rejection of our New Theory, is expressed in Fundamentals of Aerodynamics prepared for Naval Aviation Schools Command by the Naval Training, US Navy (1998). The goal of Chapter 4 on Lift and Stalls is stated as
  • The purpose of this lesson is to aid the student in understanding lift and stalls as they relate to aerodynamics. 
  • Upon completion of this unit of instruction, the student aviator will demonstrate knowledge of basic aerodynamic factors that affect airplane performance.
We read:
  • Lift and drag are produced by different physical processes. Lift is produced by a lower pressure distribution on the top of an airfoil than on the bottom.
  • A cambered airfoil is able to produce an uneven pressure distribution even at zero AOA. Because of the positive camber, the area in the streamtube above the wing is smaller than area in the streamtube below the wing and the airflow velocity above the wing is greater than the velocity below the wing.
  • As the angle of attack of an (symmetric non-cambered) airfoil is increased, the leading edge stagnation point will move to a lower point on the leading edge. This shift has the effect of causing the area of the stream- tube above the airfoil to decrease. As with an increase in camber, the velocity of the airflow above the airfoil will increase, lowering the static pressure above the airfoil, increasing the differential pressure and, therefore increasing lift. 
We see that US Navy seeks to make pilots believe that lift is generated by "larger distance lower pressure above", which is the most common popular explanation. But this is known by everybody with the slightest knowledge of aerodynamics to be an incorrect pseudo-scientific explanation of the generation of lift of a wing.

In addition US Navy imprints into the pilots minds a picture of the pressure distribution at the trailing edge (displayed above) which is incorrect: The high pressure at the trailing edge seen in the picture is not present for a real wing and in the correct New Theory, only in the incorrect Old Theory.

If the above is representative of the level of the science delivered by AIAA to the US Navy, no wonder that our New Theory is not understood by AIAA and therefore is rejected.

PS The Naval Avaiation Schools Command sends the following  SAFETY / HAZARD AWARENESS NOTICE:
  • Safe training is the number one goal. Each year at training commands, lives are lost and thousands of man hours and millions of dollars are wasted as the result of accidents. Most of these accidents could have been prevented. They are the result of actions performed incor- rectly, either knowingly or unknowingly, by people who fail to exercise sufficient foresight, lack the requisite training, knowledge, or motivation, or who fail to recognize and report hazards. 
  • It is the responsibility of all Department of Defense personnel to report all mishaps and near misses. If a mishap, hazardous condition or near miss occurs let your instructor know immediately
  • Students will report all hazardous conditions and near misses to the command high-risk safety officer via their divisional/departmental high-risk safety officer.
Although not DoD personnel I hereby report to the high-risk safety officer that there is a serious mishap in the explanation of lift presented. 

Inga kommentarer:

Skicka en kommentar