CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Modeling flow regime transition using the LES turbulence model

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 26, 2022, 17:25
Default Modeling flow regime transition using the LES turbulence model
  #1
New Member
 
Rick
Join Date: Aug 2022
Posts: 18
Rep Power: 4
Rick is on a distinguished road
Hi Everyone,

I'm trying to simulate flow through an aortic valve. The inlet and outlet boundary conditions are pressure inlet and outlet, respectively. At the outlet, the specified pressure waveform is static pressure and remains zero for the first 0.015sec, while the dynamic pressure at the inlet increases from zero to 500 Pa during this time interval. The orifice area of the valve remains constant during this time and is equal to 5 percent of the inlet cross-sectional area. Using the laminar flow regime assumption, I have no backflow at the outlet from the beginning time point, while using the LES turbulence model there is backflow from the beginning till t=0.014sec. In other words, it seems the flow requires a greater pressure gradient to pass the valve using this turbulence model.


I know in turbulent flow more energy is dissipated by eddies. However, during this time interval, the Reynolds number is always less than 800. So, the results should be similar to those obtained by laminar flow. Does this mean that LES cannot model the transition accurately and is not suitable for this simulation? It has been used in literature but was not validated.

Many thanks in advance!
Rick is offline   Reply With Quote

Reply

Tags
les, transition, turbulence modeling

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
What are the best settings for a channel flow simulation? Ashkan Kashani CFX 3 October 13, 2022 22:36
[swak4Foam] swakExpression not writing to log alexfells OpenFOAM Community Contributions 3 March 16, 2020 19:19
Water subcooled boiling Attesz CFX 7 January 5, 2013 04:32
Turbulence dampening due to magnetic field in LES and RAS eelcovv OpenFOAM 0 June 8, 2010 12:35
Advanced Turbulence Modeling in Fluent, Realizable k-epsilon Model Jonas Larsson FLUENT 5 March 13, 2000 04:27


All times are GMT -4. The time now is 20:38.