CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   time dependent problem (http://www.cfd-online.com/Forums/fluent/49468-time-dependent-problem.html)

Adrian October 9, 2008 13:55

time dependent problem
 
hi all

Im still working with cars Im trying to do depedent time calculations and I dont know which values do I have to put in Time step size (s) Number of time step and max. Iterations per time step to begin this test thank so much if anybody can help me greetings to you all

Paul October 9, 2008 15:48

Re: time dependent problem
 
What kind of time calculations do you mean?

Prasad October 10, 2008 06:32

Re: time dependent problem
 
I understand that you are working on the aerodynamics of a moving car. Please correct me if I'm wrong. May I ask why you need to do transient analysis for this?

Adrian October 10, 2008 09:50

Re: Hi paul , Prasad ... from Adrian
 
Hi matey Thank for your concern on my works and I working with cars and The flow pattern aroumd the car is highly unsteady beside the flow behind the car is separated so to get a good drag and lift result I guess that I must do unsteady analisis and to star this analysis I need some values of Time step size(s) Number of time steps and Max. Iterations per time step

Greetings Mateys and take care

Will October 10, 2008 14:01

Re: Hi paul , Prasad ... from Adrian
 
To start off I would suggest using the time it takes the freestream flow to pass through one cell.

Prasad October 10, 2008 16:05

Re: Hi paul , Prasad ... from Adrian
 
For a car speed of 100 m/s (or avg speed of incoming air - something like avg wind tunnel air speed), I would start with a quarter of a milisecond. But again, it depends upon the solution stability.

Adrian October 14, 2008 22:24

Thank you all paul , Prasad ... from Adrian
 
Thank you guys I will try anything else to do this test? I mean another advice?Can you tell your experience in cars if you did some thank you Adrian


All times are GMT -4. The time now is 12:39.