# Points of action for thrust and drag forces and lift-drag ratio

• Slickk64
In summary, drag is a force that acts against an airplane's motion, while thrust is the force that propels it forward. The thrust and drag must be equal for level flight. The lift-drag ratio measures an airplane's efficiency in generating lift and minimizing drag, and it is affected by the wing configuration, with longer and thinner wings having a higher lift-drag ratio.
Slickk64
Hi,

Can anyone help explaining the points of action of drag and thrust forces on an aeroplane in flight and also the realtionship between Lift-Drag ration and wing configuration?!

Any help would be great!

I would check out

http://www.spitfireperformance.com/

They will either have some of what you seek or links to where it could be found.

Multiplayer combat sim forums have much discussion on lift to drag ratio because your virtual life depends on this knowledge in the arenas.

Warbirds, IL2, Aces High II...etc.

Sure, I'd be happy to help explain the points of action of drag and thrust forces on an airplane in flight, as well as the relationship between lift-drag ratio and wing configuration.

Drag is a force that acts in the opposite direction of an airplane's motion. It is caused by the resistance of the air against the airplane's surface. There are two types of drag: parasitic drag and induced drag. Parasitic drag is caused by the friction of the air against the airplane's surface, while induced drag is caused by the production of lift.

Thrust, on the other hand, is the force that propels the airplane forward. It is generated by the airplane's engines or propellers. The direction of thrust is in the same direction as the airplane's motion.

In order for an airplane to maintain level flight, the thrust force must be equal to the drag force. If the thrust is greater than the drag, the airplane will accelerate. If the drag is greater than the thrust, the airplane will decelerate.

Now, let's talk about the relationship between lift-drag ratio and wing configuration. The lift-drag ratio is a measure of how efficiently an airplane can generate lift and minimize drag. A higher lift-drag ratio means that the airplane can fly at a higher angle of attack (the angle between the airplane's wing and the relative wind) and generate more lift with less drag.

The wing configuration plays a crucial role in determining the lift-drag ratio. Generally, a longer and thinner wing will have a higher lift-drag ratio compared to a shorter and thicker wing. This is because a longer wing has a higher aspect ratio (the ratio of the wing's length to its width), which reduces induced drag. Additionally, certain wing shapes, such as swept wings, can also improve the lift-drag ratio by reducing the effect of shock waves.

I hope this helps clarify the points of action of drag and thrust forces on an airplane in flight and the relationship between lift-drag ratio and wing configuration. Let me know if you have any further questions!

## 1. What are points of action for thrust and drag forces?

The points of action for thrust and drag forces are the locations on an object where these forces are applied. For thrust, this is typically at the engine or propeller of an aircraft, while for drag it is usually at the center of pressure of the object.

## 2. How do these forces affect an object's movement?

Thrust is a force that propels an object forward, while drag is a force that opposes the motion of the object. These forces can affect an object's speed, direction, and stability. For example, a greater amount of thrust will result in faster movement, while a higher amount of drag will slow down the object.

## 3. What is the lift-drag ratio and why is it important?

The lift-drag ratio is the ratio of the lift force to the drag force on an object. It is an important measure of an object's aerodynamic efficiency, as a higher lift-drag ratio indicates that the object can generate more lift while minimizing drag. This is desirable for efficient movement through air or other fluids.

## 4. How can the lift-drag ratio be improved?

The lift-drag ratio can be improved by reducing drag and increasing lift. This can be achieved through various design considerations such as streamlining the object's shape, reducing surface roughness, and utilizing technologies like winglets and spoilers to manipulate airflow.

## 5. Are there any limitations to the points of action for thrust and drag forces and lift-drag ratio?

Yes, there are limitations to these concepts as they are affected by various factors such as air density, speed, and angle of attack. Additionally, the design and materials of the object can also impact these forces and ratios. Therefore, it is important for scientists and engineers to carefully consider these factors when designing objects for optimal performance.

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