CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Understanding the sonicFoam tutorial energy equation

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 13, 2019, 06:01
Default Understanding the sonicFoam tutorial energy equation
  #1
New Member
 
Join Date: Dec 2015
Posts: 24
Rep Power: 10
metalfox is on a distinguished road
In the supersonic flow over a forward-facing step tutorial (https://www.openfoam.com/documentati...utorialse6.php), the energy equation is stated to be:
\frac{\partial\rho e}{\partial t}+\nabla\cdot(\rho\mathbf{U}e)-\nabla\cdot\frac{k}{C_{v}}\nabla e=p\nabla\cdot\mathbf{U}

I have doubts regarding the p\nabla\cdot\mathbf{U} term. It appears in the right hand side of this equation. However, in the general energy equation (https://cfd.direct/openfoam/energy-equation/), there is a term \nabla\cdot(\mathbf{U}p), which appears in the left hand side.

If I'm not mistaken, \nabla\cdot(\mathbf{U}p) expands to p\nabla\cdot\mathbf{U}+\mathbf{U}\cdot\nabla p.

Why \mathbf{U}\cdot\nabla p vanishes in the above equation?

Isn't there a missing minus sign for the p\nabla\cdot\mathbf{U} term?
metalfox is offline   Reply With Quote

Reply

Tags
energy equation, sonicfoam


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Energy equation in rhoCentralFoam (revisited) usv001 OpenFOAM Programming & Development 4 September 6, 2024 08:51
Energy equation - where is the turbulent kinetic energy? usv001 OpenFOAM Programming & Development 1 January 25, 2022 16:04
energy equation in rhoCentralFoam nakul OpenFOAM 0 October 10, 2010 16:07
ATTENTION! Reliability problems in CFX 5.7 Joseph CFX 14 April 20, 2010 16:45
Viscosity and the Energy Equation Rich Main CFD Forum 0 December 16, 2009 15:01


All times are GMT -4. The time now is 13:42.