Planes Are Always in the Air

Has published ten science-based books, including Monsters: The Hindenburg Disaster and the Birth of Pathological Technology (Basic Books 2015). He also has logged over 1000 flying hours as a private flight pilot. 

IN BRIEF

• At a strict mathematical scale, engineers can make planes that remain at a height. However, equations do not explain why aerodynamic lift happens.
• Two different theories reveal the forces and elements of lift. Both approaches need to be completed explanations.
• Aerodynamicists have recently attempted to bridge the gap in understanding. Still, no consensus exists.

In December of 2003, to mark centennial anniversary celebrations of the initial flight made by the Wright brothers, The New York Times featured a story titled “Staying Aloft; What Does Keep Them Up There?” The article’s purpose was a straightforward question: What keeps planes up in the air? To answer this question, The Times looked towards John D. Anderson, Jr. as the head of aerodynamics at the National Air and Space Museum and author of several textbooks.

Anderson has said there needs to be a consensus on what causes the aerodynamic force referred to as lift. “There is no simple one-liner answer to this,” Anderson said in The Times. There are many different opinions on the question, including some based on “religious fervor.” More than 15 years later, after the announcement, there remain various theories of what causes lift, each with a large number of enthusiastic supporters. In the development of flight, this scenario could be clearer could be clearer. The nature-based processes that evolved, acting in complete obliviousness and with no knowledge of physics, resolved the mechanical problem of aerodynamic lift the birds that flew eons ago. Why is it difficult for scientists to determine why birds and airliners are on the horizon?

The confusion is exacerbated by the fact that theories of lift are based on two distinct levels of abstraction: the technical and non-technical. They’re both complementary, not incompatible. However, they differ in their goals. One is a mathematical theory, a world characterized by the medium of analysis. It comprises symbols, equations, computer simulations, and numbers. There is no significant disagreement on the most appropriate equations or solutions. The goal of mathematics is to create accurate predictions and provide results beneficial to aeronautical engineers involved in the complicated design of aircraft.

A wealth of data taken from the streams (lines made of particles) in wind-tunnel testing and laboratory tests on the nozzle and Venturi tubes and more give overwhelming evidence that, according to Bernoulli’s theory, it is accurate and reliable. However, several reasons show that Bernoulli’s Theorem is not a comprehensive theory of lifting. While it is a known observation that air moves faster when curved, Bernoulli’s theory alone cannot provide a reason for this. Also, this theorem needs to be revised to explain why the higher speed above the wing was created in the first place.

There are many faulty explanations for the faster velocity. Based on the most popular one, which is the “equal transit time” theory–parcels of air that separate from the leading edge of the wing must be joined on the trailing edge. The top box will be faster since the upper lot can travel further than the lower one within a specific time. The problem is that there is no scientific reason for the two fields to meet at the trailing edge in tandem. Indeed, there is no reason to believe they should, as the evidence suggests that the air above is moving much faster than the equal transit theory explains.

A well-known “demonstration” of Bernoulli’s principle is utilized in numerous popular websites, including YouTube videos and specific textbooks. The method involves placing a piece of paper horizontally in your mouth while blowing on the curving top of it. The form rises, showing how to create the Bernoulli effect. The opposite should be observed when you blow on the sheet’s bottom. The velocity of the air moving beneath it ought to pull the sheet downwards. In reality, however, the page rises.