### AERODYNAMICS

It is a broad subject. It is itself a branch of engineering. In the aerodynamics the study of air around a solid body has to be done. In this post we will discuss aerodynamics of an aircraft. The aerodynamics of an aircraft involves study of its movement and its mechanism.
In the aerodynamics the motion of aircraft, mechanism of flying, forces acting on the aircraft, stability of aircraft etc. are the subjects which would be elaborated. The many parameters are measured in the air that is present around the aircraft.

### Forces acting on the aircraft

In a moving aircraft there are mainly four forces that acts in the different direction. Each force is important for the successful flight of the aircraft. These forces are thrust, drag, lift and weight.
Thrust acts in the forward direction i.e. in the direction of the movement of aircraft, and the drag acts opposite to the thrust force i.e. opposite to the motion of the aircraft.
Lift is the force acts in the upward direction of the motion that provides altitude to the aircraft and opposite to this weight of the aircraft i.e. force due to gravity acts as a force against to the lift.
These forces of aircraft can also be classified as artificial and natural forces. Artificial forces are those which can be controlled and manipulated by pilot and natural forces are those which cannot be manipulated by pilot. Lift and Thrust forces are artificial forces, weight is the natural force and drag is partially artificial force.

### Axes of the Aircraft and Stability of the Aircraft

In the aircraft, three axes comes in picture. These are Lateral axis, longitudinal axis and vertical axis. The movement or manoeuvre of airplane is based on these axes. The stability of the aircraft depends on these axes.
The movement of aircraft takes place along these three axes. These movements are known as Pitch, Roll and Yaw.

#### Pitch or Pitching in the aircraft

Pitching is the movement of aircraft about the lateral axis. Pitching movement is responsible for up and down movement of aircraft. Take-off and landing is possible with pitching movement of the aircraft. Elevator is the part which creates this movement in the aircraft.

#### Rolling of the aircraft and longitudinal stability

Rolling is the movement of aircraft about longitudinal axis. Rolling movement is responsible for up and down movement of wings. If one wing goes up then other wing goes down, So Rolling is generally the banking of wings. Ailerons performs this operation which are situated at the end of the both wings.

#### Yaw or yawing in the aircraft

Yawing is the movement of the aircraft about vertical axis. Yaw movement is responsible for left and right movement of aircraft. Radar is used for the yaw movement and vertical stability of the aircraft. Vertical stability is generally called the Directional stability.

#### Yaw cause Roll and Roll cause Yaw

Yes, its true. These two movements are complementary to each other and both happens simultaneously. When aircraft takes a turn the wing also goes down for successful turning of aircraft. So the yaw and roll happens together.

### Aerofoil

In the mechanics of flight, the concept of aerofoil is important. Aerofoil is an application of Bernoullis theorem. The aerofoil is a shape that is responsible to provide the lift in the aircraft. The cross-section of the wing in the airplane will be provided the shape of aerofoil to generate the lift.
Aerofoil provides the difference in pressure that causes the system to move upward.