Does the induced drag increase with speed?

In summary, the induced drag increases with an increasing air speed for a given angle of attack. However, for a fixed AOA during ground roll, the induced drag will not be as significant compared to when the pilot pulls back on the stick for take off. This is because pulling back on the stick increases AOA, lift, and subsequently, induced drag. Additionally, the induced drag is proportional to V2. For low speed RC airplanes during ground roll, the biggest type of drag is not induced drag, as it is during the take off phase.
  • #1
MaxKang
20
0
Does the induced drag increase with an increasing air speed for a given angle of attack?

Most graphs I found online seem to suggest that the amount of induced drag increases as the speed increases but they actually allow the AOA to vary so I was wondering for a case of fixed AOA(ground roll for take off), how the amount of induced drag will vary.

Also for low speed RC airplanes, what is the biggest type of drag on ground roll before taking off? I think I read somewhere on the Boeing website saying that for bigger aircraft, up to 70% is the induced drag for take off but I am not sure if this was related to the ground roll phase or immediately after the plane has taken off.

Thanks!
 
Physics news on Phys.org
  • #2
For a fixed AOA, the induced drag will increase more. Also the lift will increase. The reason that they reduce the AOA is to keep lift constant for the increasing speed. They are interested in level flight with increasing speed.

During the ground roll, the induced drag would not be nearly as great as when the pilot pulls back on the stick for a take off. Pulling back on the stick pulls the nose up, increases AOA, increases lift, and causes a corresponding increase in induced drag.
 
Last edited:
  • Like
Likes MaxKang
  • #3
As a first approximation, the induced drag will be proportional to V2.
 
  • Like
Likes MaxKang
  • #4
Thank you so much!
 

1. Does the induced drag always increase with speed?

No, the induced drag does not always increase with speed. There is a specific speed called the "minimum drag speed" or "optimum speed" where the induced drag is at its lowest. This speed varies depending on the shape and size of the object.

2. How does the shape of an object affect induced drag at higher speeds?

The shape of an object can greatly affect the amount of induced drag at higher speeds. Objects with a rounded, streamlined shape will experience less induced drag compared to objects with a flat or blunt shape. This is because a streamlined shape allows for smoother airflow, reducing the formation of vortices that contribute to induced drag.

3. Is induced drag the only type of drag that increases with speed?

No, there are two types of drag that increase with speed: induced drag and parasite drag. Induced drag is caused by the production of lift, while parasite drag is caused by the friction and pressure differences between the object and the surrounding air. Both types of drag increase with speed, but the rate at which they increase varies depending on the object's shape and size.

4. How does air density affect induced drag at different speeds?

Air density plays a significant role in the amount of induced drag experienced at different speeds. At higher altitudes where the air is less dense, the induced drag will be lower compared to lower altitudes where the air is denser. This is because the production of lift is influenced by the density of the air, and a lower density will result in less induced drag.

5. Can induced drag be reduced at high speeds?

Yes, induced drag can be reduced at high speeds by using techniques such as wing sweep, winglets, and airfoil design. These techniques help to decrease the formation of vortices and improve the overall aerodynamics of the object, resulting in lower induced drag. However, these techniques may also increase parasite drag, so it is important to strike a balance between the two types of drag for optimal performance.

Similar threads

Replies
10
Views
2K
Replies
5
Views
648
  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
  • Classical Physics
Replies
6
Views
1K
  • Aerospace Engineering
Replies
30
Views
4K
  • Classical Physics
Replies
16
Views
1K
  • Mechanical Engineering
Replies
3
Views
4K
Replies
3
Views
1K
Replies
130
Views
7K
Back
Top