Air pressure and force of lift

[spidey64]

I know about Bernoulli's principle and that a difference of pressure below and above a wing create lift, but I cannot find anywhere a formula or any information on how to find the amount of lift given the surface area of the wing and the difference in pressure as a percentage of atmospheric pressure...my book is not helpful at all.

 

[spidey64]

I've found that force = area X pressure, which of course makes sense...but given that my problem gives me the difference of pressures below and above as 4% atmospheric pressure, is the pressure value in that formula .04?

 

[charng]

I can understand your frustration with not being able to find a specific formula or information on calculating the amount of lift based on wing surface area and pressure difference as a percentage of atmospheric pressure. This is because there is no one definitive formula for calculating lift, as it depends on various factors such as air density, velocity, and wing design.

However, Bernoulli's principle does provide a fundamental understanding of how lift is generated. It states that an increase in air velocity leads to a decrease in pressure, and vice versa. This is why the shape of a wing, with its curved upper surface and flat lower surface, is crucial in creating lift. As air flows over the curved upper surface, it speeds up and its pressure decreases, creating a lower pressure area compared to the flat lower surface. This pressure difference results in an upward force, which is the lift.

To calculate the amount of lift, engineers and scientists use a combination of mathematical models, wind tunnel experiments, and computer simulations. These methods take into account various factors such as wing shape, angle of attack, air density, and velocity to determine the lift force. Therefore, it is not possible to provide a single formula that can accurately calculate lift for all situations.

In summary, while there is no specific formula for calculating lift based on wing surface area and pressure difference as a percentage of atmospheric pressure, understanding Bernoulli's principle and considering other factors can provide a fundamental understanding of how lift is generated. To accurately calculate lift, a combination of methods and factors must be taken into account.