Thrust
Thrust is another one of the four main forces acting upon an airplane. Thrust, also called push is the force of motion in forward direction. Thrust is the force that allows the aircraft to move through the air and is directionally opposite to drag. Thrust is also a vector quantity (magnitude and direction). The direction is directly opposite to the direction of accelerated gas from a turbine (the air is forced/pushed backwards and the plane moves forward).
In an airplane thrust is generated when air is pushed in one direction allowing the aircraft to move in the opposite direction. It can be generated in a number of different ways such as spinning propellers, jet engines or turbines.
In an airplane thrust is generated when air is pushed in one direction allowing the aircraft to move in the opposite direction. It can be generated in a number of different ways such as spinning propellers, jet engines or turbines.
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Propellers work in a similar way to wings generating lift, only propellers can work in a forward motion instead of upward. Just like wings, propellers utilise the angle and speed of the spinning blades to generate a difference in pressure between the front and back of the propeller allowing the forward motion of the plane. Turbines and jet engines however, work differently. These engines work by sucking in air at the front of the turbine with a fan. It then travels through a compressor, where the air pressure is raised. The compressor works similarly to propellers as it consists of many blades which spin at a high speed to force the air backwards. As the pressurised air moves back it is ignited with fuel by an electric spark which expands the blast and increases the backwards force. As the air shoots out the back of the turbine, the plane moves forward. There are many different types of jet engines which are used in various aircrafts to create thrust.
Drag
Drag is the force acting upon the aircraft which is directionally opposite to thrust. In basic terms, drag can be described as aerodynamic friction. Just like all forces drag is a vector quantity. The direction is opposite to the motion of the aircraft and the magnitude varies based on factors such as speed or shape (of the aircraft). Drag generally slows down the movement of an object traveling through a fluid (liquid or gas). As the object moves through a gas or liquid, the fluid pushes back on the object which slows its momentum. A fixed wing aircraft (airplane) has an optimised shape of its wings which allows for minimal drag. This can be seen in the image to the right.
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Physicists have classified different types of drag depending on what each one does.There are: form drag, skin friction, interference drag, lift-induced drag and wave drag.
One type of drag: Form Drag, comes from the shape of the object. For example a truck with a flat face will have more drag than a sports car with its thinner body. This differs to another classification such as Skin Friction which forms from the interaction between the fluid and the surface of the object. For example a smooth waxed surface would have less drag than a rough surface.
One type of drag: Form Drag, comes from the shape of the object. For example a truck with a flat face will have more drag than a sports car with its thinner body. This differs to another classification such as Skin Friction which forms from the interaction between the fluid and the surface of the object. For example a smooth waxed surface would have less drag than a rough surface.