CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Pre-Processing

how to set URANS turbulence model in unsteady flow simulation

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 25, 2017, 08:52
Default how to set URANS turbulence model in unsteady flow simulation
  #1
New Member
 
Zheng Liu
Join Date: Oct 2016
Posts: 6
Rep Power: 9
TimLiu is on a distinguished road
Hi FOAMERS,

I am new of turbulence modeling. I am quite confused in setting the boundary conditions of turbulence models.

For example, the k-epsilon model in steady state conditions, if I want the inlet turbulence kinetic energy having the intensity of 5%, I can set the inlet type to be turbulenceIntensityKineticEnergyInlet with the key word "intensity". For the value of turbulence kinetic energy, it can be calculated based on the formula " k = 1.5(U * I)^2 ", where U is the mean flow velocity, I the turbulence kinetic energy (see: https://www.cfd-online.com/Wiki/Turb...ary_conditions).

However, in unsteady flow conditions, the inlet flow velocity is keep changing. My question is, in URANS model, is the inlet turbulence kinetic energy (also dissipation rate) also varying with time? If so, How to set the boundary conditions since the turbulence kinetic energy is not a constant value?

Thanks in advance
Zheng
TimLiu is offline   Reply With Quote

Reply

Tags
openfoam, rans, turbulence, urans

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Issues on the simulation of high-speed compressible flow within turbomachinery dowlee OpenFOAM Running, Solving & CFD 11 August 6, 2021 06:40
Multiphase simulation of bubble rising Niru CFX 5 November 25, 2014 13:57
Water subcooled boiling Attesz CFX 7 January 5, 2013 03:32
K - epsilon VS SST turbulence model Maicol Main CFD Forum 0 November 30, 2012 16:25
turbulence model simulation in unsteady flow Chang Main CFD Forum 2 February 12, 2005 06:28


All times are GMT -4. The time now is 23:03.