Pseudo Transient approach
Hello,
does anyone have any tutorial or simulation which uses pseudo transient approach as an initial guess for flow field initialization? I am running a high speed compressible flow and would really appreciate any help, |
Re: Pseudo Transient approach
A tutorial what for? Just switch it on, set your time step (in your case 1.E-08) and run it! There's nothing special that could be mentioned in a tutorial!!!
hope this helps Piet |
Re: Pseudo Transient approach
when i am running steady state option for high speed compressible flow... it is giving me a converged solution.
But when i run the same case for pseudo-transient case, the simulation stops due to negative densities in more than 100 cells.. of course my time step was 0.1 will decreasing my time step to 1E-8 solve this issue?? |
Re: Pseudo Transient approach
try reducing residual tolerance for primary variables to avoid this problem
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Re: Pseudo Transient approach
Yes, your are absolutely right. It can solve your problem. Maybe 1.E-8 is not small enough! Try to lower it further for several hundred steps and enhance it from time to time. Any hint for such cases is to start the calculation with a dependency of temperature. This means rho = f(T) and switch back after lets say 100 iterations.
best regards Piet |
What is the difference between pseudo transient simulation and transient simulation?
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Transient simulation is to solve the problem in time-accurate fashion, while pseudo transient is method to get the steady state solution
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In what problems, we are recommended to apply pseudo transient method? Thanks |
[QUOTE=itsme_kit;499259]Hi
In what problems, we are recommended to apply pseudo transient method? Could someone having experience with pseudo transient method kindly comment when or in which cases does one implement in the soution methods in fluent |
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Pseudo Transient
Hi,
I am running a simulation using Pseudo Transient Flow (compressible, turbulent, internal flow). I saw that my residual the became flat very soon. Is that correct? When I run it normally my residuals go up and down like crazy. This is my first time running pseudo transient. Thank you for your help Denis |
Pseudo Transient/Mixed Transient Steady State
Hello,
I was looking for advice on how to go about it or what is possible. I am using CHTmultiregionfoam (Actually a derivative of it) and would like to change something to improve calculational speed. Because the flow in the fluid region takes very short periods of time to reach a steady state, it would be desirable to model this region as a steady region with the solid regions remaining in transient. The desire is to resolve the steady flow profile at each time step with the new solid region boundary conditions applied until convergence. This would thus make the new flow solution independent of the prior time steps. And based on my fully transient runs this would not be a bad assumption and would help with CFL limitations caused by the fluid region. Any advice would be appreciated. I am working in openfoam but I'm mostly looking for advice or pointers to resources that have done similar. Cole |
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Can we also obtain variation of some parameter with time by using pseudo transient method ?
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/Deleted, as wrong message quoted.
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