Why do airplane wings have round leading edges?

409 views

I don’t understand all the internet explanations using terms like “Range of attack” “Stall speed”

I’m trying to understand why it matters that the wing has a blunt front, if just angling a flat sheet slightly upwards should in my theory still lift it up at speed.

Although those round edges intuitively make sense somehow, i just want to understand why they work.

In: 0

9 Answers

Anonymous 0 Comments

> if just angling a flat sheet slightly upwards should in my theory still lift it up at speed.

It will, but it doesn’t do so very efficiently. With sufficient thrust, almost anything can be made to fly, but when you design an airplane; and especially a long distance transport plane, you want to minimize drag as much as possible. The more drag your wing creates, the more thrust you need to overcome that drag, which translates into more fuel burned. And fuel costs money, and airlines operate on thin profit margins.

To minimize drag you want the air to flow smoothly over the wing. The reason you don’t want a sharp leading edge is because the air can’t “turn the corner” fast enough, and so instead of flowing smoothly over the wing, the airflow will “separate” and create a large region of turbulent flow over the upper surface of the wing. To avoid going into the math, think of it a bit like driving a car – if you try to turn too fast, your car might go off the road. [Here is a picture of a flat plate wing in a wind tunnel](https://i.stack.imgur.com/kHr6r.jpg). You can see that the air flowing over the top surface doesn’t follow the shape of the wing, and lot of turbulence is generated as a result.

This condition is known as “stall”, and it results in such a large increase in drag and decrease in lift that most planes cannot generate enough lift to fly in this condition (some fighter aircraft have such powerful engines that they can). Any wing has an critical angle of attack at which it will stall, but for a flat plate wing this angle is very small, such that it is hard to generate much lift at all without stalling.

You are viewing 1 out of 9 answers, click here to view all answers.