Is Negative Drag a Real Concept in Fluid Dynamics?

  • Context: Undergrad 
  • Thread starter Thread starter mista_chewey
  • Start date Start date
  • Tags Tags
    Definition Drag
Click For Summary
SUMMARY

The discussion centers on the concept of "negative drag" in fluid dynamics, which is deemed a misnomer. Participants clarify that drag is a force opposing an object's motion through a fluid, while thrust is the force propelling the object forward. The assertion that "thrust IS negative drag" is rejected, as thrust and drag serve distinct roles in physics. The consensus is that negative drag is not a valid term within the established definitions of fluid dynamics.

PREREQUISITES
  • Understanding of fluid dynamics principles
  • Familiarity with forces: drag and thrust
  • Basic knowledge of physics terminology
  • Mathematical definitions related to forces in motion
NEXT STEPS
  • Research the mathematical definitions of drag and thrust in fluid dynamics
  • Explore the principles of fluid resistance and its impact on motion
  • Learn about the applications of thrust in aerospace engineering
  • Investigate common misconceptions in physics terminology
USEFUL FOR

Students and professionals in physics, aerospace engineers, and anyone interested in understanding the fundamental forces acting on objects in fluid environments.

mista_chewey
Messages
6
Reaction score
0
my first post but i had to get this out before i explode!
this has been bugging me to hell

on this other forum i visit. there are a bunch of people insisting on "negative drag"
is there such a thing?

from what i understand drag is a force acting on an object moving through a fluid.
and thrust is a force propelling the object through the liquid.

so negative drag would be a force enacted on the object by the fluid in the direction of movement. so the object will be propelling itself wouldn't it?

there is also another statement that says "thrust IS negative drag"
thrust is constantly trying to over come drag so how can they be the same thing?

so is it the same thing?
 
Last edited:
Physics news on Phys.org
Negative drag is not a proper term. The word "drag" has a very specific meaning associated with it along with a mathematical/engineering definition. The engineering definition alone prevents the usage in the way that you are saying. There is absolutely no reason to use a term like "negative drag." Would any of these people say something like "you need to negative push to open the door?"

They are the same thing in that they are both forces, but that is the extent of their similarities.
 
so my understanding of thrust and drag is correct right?
 

Similar threads

Undergrad Drag Coefficient of a 'flexible' object (e.g. a piece of paper)
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Calculating Water Pool Depth: Factors to Consider in Fluid Dynamics
  • · Replies 13 ·
Replies
13
Views
2K
Undergrad Calculating the drag force on a spherical object with holes
  • · Replies 16 ·
Replies
16
Views
4K
Undergrad Drag equation - relative flow velocity
  • · Replies 11 ·
Replies
11
Views
4K
Undergrad Express drag force/acceleration/velocity as function of time
  • · Replies 14 ·
Replies
14
Views
2K
Graduate Beyond Viscous Drag, Cavitation, Laminar Flow, & Reynolds
  • · Replies 15 ·
Replies
15
Views
3K
Graduate Velocity change under drag and other forces: small mass, large delta-t
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Fluid dynamics: drag coefficient and pressure at the stagnation point.
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Coefficient of drag and surface smoothness
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Air drag force: Why heavy objects accelerate faster?
  • · Replies 2 ·
Replies
2
Views
2K