CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > Siemens > STAR-CCM+

Engine Simulation: Help with Physics Models

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

LinkBack Thread Tools Search this Thread Display Modes
Old   July 30, 2018, 18:28
Question Engine Simulation: Help with Physics Models
New Member
Austin Nolen
Join Date: Jul 2018
Posts: 1
Rep Power: 0
Anolen is on a distinguished road
Hey everyone,

I am working on a simple simulation for a final project, and am a bit stumped with setting up my simulation.

I am comparing the average density in two cylinders, one with a single intake valve, and one with two (to compare a 2-valve vs. 4-valve cylinder head). I am trying to make it as simple as possible, so there are no moving components etc. Nonetheless, I am rather stumped while trying to figure out an effective setup for my physics model. In terms of regions, there is only an inlet and walls, as I only want to measure density after a certain amount of time. It is a grossly simple simulation/ comparison, but will work for the project if I can get it to run properly. I have tried a stagnation inlet and a velocity inlet over a period of time and I am running into continuous problems. Residuals are all over the place and very high, and I have yet to see a density that looks reasonable.

Currently I am using the following physics models: 3-D, steady, coupled, ideal gas, k-omega turbulence and cell quality remediation.

I've attached a picture of the model I am using, if I am leaving out important info let me know, I'm just not sure where to look or what to change at this point so any advice would be appreciated.

Thanks everyone.
Attached Images
File Type: jpg Final Project - 2v Sim_Geometry Scene 1.jpg (12.9 KB, 8 views)
Anolen is offline   Reply With Quote

Old   July 31, 2018, 04:02
New Member
Join Date: Nov 2017
Posts: 5
Rep Power: 7
shelleyvander is on a distinguished road
i have a 6500 for 6 years now i got at harbor and its still a beast i hook it directly to my panel i have a permenate connection on both rails i just turn off the main so it doesnt back feed and kill a line man and flip 2 breakers i installed on the bottom of the panel plug this 220 line into the diesel generator and give it a pull mine is hooked to my 500 gallon propane tank so if the power goes out its flip 3 breakers and 1 pull i live in tornado alley we lose power alot and its awesome
shelleyvander is offline   Reply With Quote

Old   July 31, 2018, 08:20
André Pinto
Join Date: Oct 2017
Posts: 81
Rep Power: 7
AndreP is on a distinguished road
I never did Engine Simulations, only external vehicle flow, but are you sure that the K-Omega is the adequate Turbulence model for internal combustion?

While I was searching for the turbulence model to use in my project I came across some references that would indicate that K-Epsilon and K-Omega SST is good for external flow, but for Internal Combustion you would need a more robust (and heavier) turbulence.

I'm not saying it needs to be another one, but maybe you would like to do a search and find if that turbulence model will actually give you reasonable results in your problem type? Because the turbulence model is actually one of the most important settings in a CFD simulation!

Also, what mesh are you using? in the inlet and outlet, you can use Trimmer as the flow should be pretty linear, but inside the combustion chamber i think you should use Polyhedral as its a highly turbulent environment!

Also, your image is all black, so we can't really have a look what you shared or what does it look like your problem!
AndreP is offline   Reply With Quote


cylinder, engine, ice, troubleshooting

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
Tutorial files on SI engine simulation using ANSYS FLUENT Upendra FLUENT 0 September 27, 2012 11:57
diesel engine combustion simulation kebi112358 OpenFOAM 4 September 25, 2012 13:16
first Internal Engine simulation with STAR-CCM+ Weisser Siemens 8 January 10, 2011 10:53
GUI crash and simulation engine still running RPJones FLOW-3D 2 November 9, 2010 08:18
IC Engine simulation in Fluent Ravi Kiran FLUENT 0 March 5, 2006 23:48

All times are GMT -4. The time now is 11:44.