List of drag coefficient for basic shapes has no angles

Click For Summary

Discussion Overview

The discussion revolves around the drag coefficient of basic geometric shapes, particularly focusing on the cone. Participants explore the relevance of the cone's angle and the existence of a "standard cone" with specific ratios in relation to its drag coefficient.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants question the relevance of the angle of the cone's sides in determining its drag coefficient, suggesting that this information is not included in standard references.
  • There is a suggestion that a "standard cone" with certain ratios may exist, although this is not confirmed.
  • One participant notes that the drag coefficient value of 0.50 is an approximation and indicates that it may vary with the Reynolds number and cone angle.
  • A participant emphasizes the need for more precise information, especially in comparison to shapes like cubes, which have clearly defined angles.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the significance of the cone's angle on the drag coefficient, and there is no consensus on whether a standard cone exists or what its characteristics might be.

Contextual Notes

The discussion highlights limitations in available information regarding the drag coefficient of cones, particularly the absence of specific angle measurements and the dependence on various factors like Reynolds number.

B92X
Messages
2
Reaction score
0
When I type "drag coefficient" in Google, and view some of the images, the standard list of geometrical shapes come into view, such as this one:

https://upload.wikimedia.org/wikipedia/commons/thumb/3/37/14ilf1l.svg/220px-14ilf1l.svg.png

If we take the cone for example, there is a drag coefficient of 0.50. But I can't see the degrees, or the angle of the sides. Is not that very relevant?

Is there a "standard cone" with certain ratios?
 
Physics news on Phys.org
B92X said:
When I type "drag coefficient" in Google, and view some of the images, the standard list of geometrical shapes come into view, such as this one:

https://upload.wikimedia.org/wikipedia/commons/thumb/3/37/14ilf1l.svg/220px-14ilf1l.svg.png

If we take the cone for example, there is a drag coefficient of 0.50. But I can't see the degrees, or the angle of the sides. Is not that very relevant?

Is there a "standard cone" with certain ratios?
What is your guess?
 
Chestermiller said:
What is your guess?

I looked at the Collins dictionary, and it states that "a cone is a shape with a circular base and https://www.collinsdictionary.com/dictionary/english/smooth curved sides https://www.collinsdictionary.com/dictionary/english/ending in a point at the top."

I can't seem to find a definitive ratio, this would be far more obvious for a cube as it's edges are clearly at 90 degrees.
 
The value is just an approximation. Certainly, the drag coefficient will also be a function of the Reynolds number and of the cone angle. But, to get a rough estimate, using 0.5 is probably going to give a decent approximation over a typical range of Reynolds numbers and cone angles. My advice is to keep looking for additional information and references if you need a more accurate estimate.
 
  • Like
Likes   Reactions: B92X

Similar threads

  • · Replies 1 ·
Replies
1
Views
4K
  • Sticky
  • · Replies 0 ·
Replies
0
Views
12K
  • · Replies 1 ·
Replies
1
Views
5K
  • · Replies 16 ·
Replies
16
Views
5K
  • Sticky
  • · Replies 2 ·
Replies
2
Views
506K
  • · Replies 6 ·
Replies
6
Views
5K