Momentum Flux: Quick Question (Product Rule)

Click For Summary
SUMMARY

The discussion centers on the application of the product rule in the context of fluid dynamics, specifically regarding the term \(\frac{\partial(\rho u u)}{\partial x}\). The user seeks clarification on deriving the right-hand side of the equation, which is expressed as \(\rho u \frac{\partial u}{\partial x} + u \frac{\partial (\rho u)}{\partial x}\). The conclusion reached is that the user successfully understood the derivation after further consideration.

PREREQUISITES
  • Understanding of fluid dynamics principles
  • Familiarity with the product rule in calculus
  • Knowledge of partial derivatives
  • Basic concepts of density (\(\rho\)) and velocity (\(u\)) in fluid mechanics
NEXT STEPS
  • Study the derivation of the product rule in calculus
  • Explore applications of the product rule in fluid dynamics
  • Learn about the continuity equation in fluid mechanics
  • Investigate the implications of density and velocity changes in fluid flow
USEFUL FOR

Students and professionals in fluid dynamics, mathematicians focusing on calculus applications, and anyone looking to deepen their understanding of the product rule in the context of physical equations.

andrew.c
Messages
46
Reaction score
0

Homework Statement


Heya,
I can expand the term on the LHs and get the term on the RHS no problem :)
But,
I don't understand how the bottom line is arrived at; I think its basically just a backward engineering of the product rule, but I can't get it!

Any help would be useful
 

Attachments

  • momentum flux.JPG
    momentum flux.JPG
    15.1 KB · Views: 435
Physics news on Phys.org
\frac{\partial(\rho u u)}{\partial x} = \rho u \frac{\partial u}{\partial x} + u \frac{\partial (\rho u)}{\partial x}.
 
Thanks
That was easier than I thought!
 

Similar threads

Replies
23
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
5
Views
1K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
2
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K