 Airplane

# RC Airplane Aerodynamics

In this lesson, we will study how planes fly and what are the most important differences between planes so we will study the basics of aerodynamics, the basic parts of the airplane, the most important forces affecting the plane and study the wing and tail performance.

### Basic Aerodynamics

Aerodynamics is a science that is interested in studying the forces that affect a particular object as it moves through the air or any gas such as aircraft or cars, the principle of airplane work is an application of aerodynamics and here we mean Bernoulli’s Principle and Newton’s Law of Motion.

#### Bernoulli’s Principle

The faster the fluid (air), the lower its pressure. The air at the top of the wing has more movement at the same time, so it moves faster and lowers its pressure. This allows high pressure under the wing to push it up. . read more about Bernoulli’s Principle.

#### Newton’s Law of Motion

Each action has an equal and opposite reaction. The air deflects down the wing, pushing the wing up. read more about Newton’s Law of Motion.

### Airplane Component

The airplane consists of many basic and secondary components, In general, the airplane consists of the following components:

### Airplane Forces

Airplanes, like birds, are heavier than air. So in order to fly an airplane, it makes sense to overcome the effects of gravity by producing a lifting force greater than or equal to its weight. On a conventional aircraft, this lifting force is produced by the wing. We are not going to go into much detail yet, enough to say that the size and shape of the wing is what drives the lift that can lift the aircraft in the air. There are four basic forces that govern how an aircraft flies and its flight state at the same time. These four forces are (LIFT, WEIGHT, THRUST & DRAG). They are shown in the following figure:

#### THRUST Force

THRUST Force or Propulsion is the driving force that drives or pulls a plane into the air and is produced by the aircraft’s motors. The resulting thrust is the position of the motor on the airplane. There are several motors mounting locations.

#### Drag Force

Air drag is the force that resists the movement of an aircraft that moves in the air. This resistance must be overcome by pushing the motors. You can visualize how air can disrupt the movement of a plane by thinking about how water obstructs a swimmer’s movement. The principle is exactly the same although the means by which the aircraft moves is air, not water. The total drag of the plane is proportional to the square of the flight speed of the plane. This means that as the speed of the aircraft increases, the drag increases exponentially with the square of speed. In contrast, the total thrust required to maintain a constant speed is also a coupling of the speed of the square plane.

#### LIFT Force

In order to face up the weight force, the aircraft must produce lifting force. This lifting force is created by the movement of air flowing over the aircraft. The majority of lifting force is produced by the wing of the aircraft. The shape and curvature of the wing are very important as this results in a pressure difference between the upper and lower surface of the wing which in turn stimulates this lifting force. You will also learn how the size and dimensions of the wing have a big impact on how the aircraft flies.

#### WEIGHT Force

Weight is the force produced due to the mass of the plane. All materials on Earth have a mass and the total mass of the aircraft consists of fuselage, motors and electronic parts (Lipo-Batteries, ESC Controllers). The mass of the plane is distributed throughout its size, but more often the total mass of the plane is assembled at one point called the center of mass or center of gravity. This location can be considered where the aircraft will remain balanced if it is suspended from that point. The total weight of the aircraft can be represented by a force vector (weight) operating at the center of gravity. The aircraft should be designed to operate safely within a range of center of gravity positions, and therefore control surfaces must be designed for balancing.

### Conclusion

So you can build a RC airplane if the lifting force is stronger than the weight force and the thrust force is stronger than the drag force Now we have finished the theoretical study of how the plane flies Now we can move to the practical part full of calculations, dismantling and installation of various electrical and mechanical parts We recommend that you start with the following articles: