Incorrect Lift Theory - NASA
The theory described on this slide is one of the most widely circulated, incorrect explanations. The theory can be labeled the "Longer Path" theory, or the "Equal Transit Time" theory. The theory states that airfoils are shaped with the upper surface longer than the bottom.
Bernoulli and Newton | Glenn Research Center | NASA
2024年11月13日 · There is also an incorrect theory which uses Newton’s third law applied to the bottom surface of a wing. This theory equates aerodynamic lift to a stone skipping across the water. It neglects the physical reality that both the lower and upper surface of a wing contribute to the turning of a flow of gas.
Incorrect Lift Theory - NASA
The theory is based on the idea that lift is the reaction force to air molecules striking the bottom of the airfoil as it moves through the air. Because this is similar to the way in which a flat rock thrown at a shallow angle skips across a body of water, it is called the "Skipping Stone" theory of lift.
Lift Theories - NASA
2021年5月13日 · Open the slides called Aerodynamic Forces, Incorrect Theory #1, Incorrect Theory #2, and Incorrect Theory #3 (with text) and read the explanations on lift and the popular incorrect theories on how lift is
竹蜻蜓飞行原理科普，NASA官方勘误，强行用伯努利原理解释升 …
早就有人做风洞实验证实了翼型上下表面的气流并不同时到达后缘，美国国家航空航天局也明确指出在这一错误假定下使用伯努利定理无法解释升力的来源，如图5所示 [3]。 那到底升力的来源是什么呢？ 根据牛顿第三定律——作用与反作用定律，空气流过翼型后向下偏转。 根据剑桥大学巴宾斯基于2003年做出的精妙阐述 [4]，流线曲率才是关键。 在气流曲率与垂直于流线的压力梯度之间有着简单的关联 [5]： \mathrm {d}p/\mathrm {d}n=\rho v^ {2}/R ，其中坐标 n 是流线的法向坐 …
Aerodynamics: The Theory of Lift - Owlcation
2023年12月23日 · Here are three of the main theories of lift that are now known to be incorrect. "Equal Transit" theory, also known as the "Longer Path" theory, states that because aerofoils are shaped with the upper surface longer than the bottom, air molecules that pass over the top of the aerofoil have further to travel than underneath.
No One Can Explain Why Planes Stay in the Air
2020年2月1日 · Two different theories are commonly proposed to explain lift, and advocates on both sides argue their viewpoints in articles, in books and online. The problem is that each of these two...
Lift | Glenn Research Center | NASA
2024年7月11日 · Theories on the generation of lift have become a source of great controversy and a topic for heated arguments for many years. One of the most popular incorrect theories states that the upper surface of an airfoil is shaped longer than the lower surface so that the flow over the top travels faster to reach the trailing edge at the same time.
Venturi Theory | Glenn Research Center | NASA
2023年12月7日 · Venturi Theory. There are many theories of how lift is generated. Unfortunately, many of the theories found in encyclopedias, on web sites, and even in some textbooks are incorrect, causing unnecessary confusion for students. The theory described on this slide is often seen on web sites and in popular literature.
Alternative Theories of Lift | How Things Fly - Smithsonian …
Are There Alternative Explanations of Lift? The explanation of lift favored by this website states that lift is created by an imbalance of pressure against a wing—lower pressure on the top surface and higher pressure on the bottom surface. This "pressure distribution" can be calculated accurately for both subsonic and supersonic flight.