Understanding Aerodynamics

Basics of Flight

process by which an object moves, through an atmosphere or beyond it

Process by which an object moves, through an atmosphere or beyond it.

The ability to fly has fascinated humans for centuries. The principles of flight, however, are not as mysterious as they may seem at first glance. In this unit, we will explore the basic principles that allow an aircraft to fly.

The Four Forces of Flight

There are four fundamental forces that act on an aircraft during flight. These are lift, weight (or gravity), thrust, and drag.

  1. Lift is the upward force that opposes the weight of the airplane and supports it in the air. Lift is generated by the movement of air over the wings of the aircraft.

  2. Weight is the force of gravity. It acts downward and must be overcome by lift for the airplane to rise.

  3. Thrust is the force that propels the airplane forward through the air. It is produced by the engine, usually by burning fuel and expelling the resulting gases.

  4. Drag is the resistance encountered by the airplane as it moves through the air. There are two types of drag: parasitic drag, which includes form drag and skin friction, and induced drag, which is related to the generation of lift.

Air Pressure and Air Density

Air pressure and air density are two key factors that affect flight. Air pressure decreases as altitude increases, which can affect the performance of the aircraft's engine and the lift generated by the wings. Air density, which is influenced by altitude, temperature, and humidity, also affects lift and engine performance. Pilots must understand these relationships and adjust their flight plans accordingly.

Bernoulli's Principle

Bernoulli's principle is a fundamental concept in understanding how an airplane generates lift. The principle states that as the speed of a fluid (in this case, air) increases, its pressure decreases. The shape of an airplane's wing, called an airfoil, is designed to take advantage of this principle. The airfoil is curved on the top and flatter on the bottom, causing air to move faster over the top than the bottom. This creates a pressure difference, with lower pressure on top and higher pressure on the bottom, which generates lift.

In conclusion, the basics of flight revolve around understanding the four forces of flight, the role of air pressure and air density, and the application of Bernoulli's principle. These principles form the foundation for further study in aircraft operation.