Aerodynamics Definition
The Aerodynamics is the study of the motion of air, particularly its interaction with a solid object, such as an airplane wing.
Aerodynamics is a sub-field of fluid dynamics and gas dynamics, and many aspects of aerodynamics theory are common to these fields.
In fluid dynamics, the Bernoulli principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in static pressure or a decrease in the fluid’s potential energy.
Often use the term aerodynamics synonymously with gas dynamics, the difference being that “gas dynamics” applies to the study of the motion of all gases, and is not limited to air.
The formal study of aerodynamics began in the modern sense in the eighteenth century, although observations of fundamental concepts such as aerodynamic drag were recorded much earlier.
Most of the early efforts in aerodynamics were directed toward achieving heavier-than-air flight, which was first demonstrated by Wright Brothers in 1903.
Since then, the use of aerodynamics through mathematical analysis, empirical approximations, wind tunnel experimentation, and computer simulations has formed a rational basis for the development of heavier-than-air flight and a number of other technologies.
Recent work in aerodynamics has focused on issues related to compressible flow, turbulence, and boundary layers and has become increasingly computational in nature.
Fundamental concepts
Understanding the motion of air around an object (often called a flow field) enables the calculation of forces and moments acting on the object.
In many aerodynamics problems, the forces of interest are the fundamental forces of flight: lift, drag, thrust, and weight.
Of these, lift and drag are aerodynamic forces, i.e. forces due to airflow over a solid body.
Often find the calculation of these quantities upon the assumption that the flow field behaves as a continuum.
Characterizing continuum flow fields by properties such as flow velocity, pressure, the density of the air, and temperature, which may be functions of position and time.
These properties may be directly or indirectly measured in aerodynamics experiments or calculated starting with the equations for conservation of mass, momentum, and energy in air flows. Density, flow velocity, and an additional property, viscosity, are used to classify flow fields.
What Is Weight?
Gravity is a force that pulls everything down to Earth. Weight is the amount of gravity multiplied by the mass of an object.
Weight is also the downward force that an aircraft must overcome to fly.
A kite has less mass and therefore less weight to overcome than a jumbo jet, but they both need the same thing in order to fly — lift.
What Is Lift?
Lift is the push that lets something move up. It is the force that is the opposite of weight.
Everything that flies must have a lift.
For an aircraft to move upward, it must have more lift than weight.
A hot air balloon has a lift because the hot air inside is lighter than the air around it, Hot air rises and carries the balloon with it.
A helicopter’s lift comes from the rotor blades. Their motion through the air moves the helicopter upward.
Lift for an airplane comes from its wings.
How Do an Airplane’s Wings Provide Lift?
The shape of an airplane’s wings is what makes it possible for the airplane to fly, Curve Airplanes’ wings on top and flatter on the bottom.
That shape makes airflow over the top faster than under the bottom. As a result, less air pressure is on top of the wing.
This lower pressure makes the wing, and the airplane it’s attached to, move up. Using curves to affect air pressure is a trick used on many aircraft.
Helicopter rotor blades use this curved shape. Lift for kites also comes from a curved shape.
Even sailboats use this curved shape. A boat’s sail is like a wing. That’s what makes the sailboat move.
What Is Drag?
Drag is a force that pulls back on something trying to move. Drag provides resistance, making it hard to move.
For example, it is more difficult to walk or run through water than through air. Water causes more drag coefficient than air.
The shape of an object also affects the amount of drag.
Round surfaces usually have less drag than flat ones. Narrow surfaces usually have less drag than wide ones.
The more air that hits a surface, the more drag the air produces.
What Is Thrust?
Thrust is the force that is the opposite of drag. It is the push that moves something forward.
For an aircraft to keep moving forward, it must have more thrust than drag.
The small airplane might get its thrust from a propeller.
A larger airplane might get its thrust from jet engines.
A glider does not have thrust. It can only fly until the drag causes it to slow down and land.