How can I break down the Navier Stokes equation? (momentum equation)

Click For Summary
SUMMARY

The discussion focuses on breaking down the Navier-Stokes equation, specifically the momentum equation, which is a differential form of Newton's second law applied to fluids. Participants reference the textbook "Bird, Stewart, Lightfoot" for detailed explanations and derivations. A Medium article by a participant outlines the derivation process, following Grainger's textbook approach. The conversation emphasizes the mathematical operation of taking the dot product of the velocity vector with the momentum equation and the gradient of the stress tensor.

PREREQUISITES
  • Understanding of fluid dynamics principles
  • Familiarity with Newton's laws of motion
  • Knowledge of vector calculus
  • Access to "Bird, Stewart, Lightfoot" textbook
NEXT STEPS
  • Study the derivation of the Navier-Stokes equation in "Bird, Stewart, Lightfoot"
  • Learn about the mathematical operations involving dot products in vector calculus
  • Explore Grainger's textbook for additional insights on fluid dynamics
  • Read the Medium article on the Navier-Stokes equation derivation for practical examples
USEFUL FOR

Students studying fluid dynamics, researchers in applied mathematics, and engineers working with fluid mechanics will benefit from this discussion.

Carbon273
Messages
17
Reaction score
4
Homework Statement
So I am trying to break down the complexity of my homework assignment where I need to perform the operation: (velocity vector)*(momentum equation) as a step to define the transport of kinetic energy equation. For the sake of academic integrity I wish to fully understand the concept by breaking it down. So my first question is, how do I gain understanding of the momentum equation in this context? How can I understand to unpack this equation. I have a feeling this is the navier stokes equation in a very condensed manner. If it is, how do I break it down, especially with the tensor embedded in there.
Relevant Equations
Equation shown below:
1567347965796.png
 
  • Like
Likes   Reactions: Delta2
Physics news on Phys.org
Sorry if this comes too close to the line for self-promotion, but a few months ago I wrote a Medium article about the derivation of the Navier-Stokes equation that mostly followed the approach in Grainger's textbook:



(Yes, I know that it says "part 1" in the subtitle, implying the existence of a "part 2". I'll get to it eventually.)
 
  • Like
Likes   Reactions: Delta2
What do you mean by "break down" exactly?
 
The momentum equation (aka, the equation of motion) is a differential version of Newton's 2nd law of motion applied to a fluid. Is that what you were asking? You are supposed to take the dot product of the velocity vector with the momentum equation. Are you asking how one mathematically takes the dot product of the velocity vector with the gradient of the stress tensor?
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 26 ·
Replies
26
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 6 ·
Replies
6
Views
874
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K