time step incompressible flow

October 31, 2006, 09:10

I want compute an unsteady incompressible flow expluctly. I gave the courant number but you obtain this message :

"You cannot use global time stepping to compute unsteady incompressible flows"

How to run?

thanks

October 31, 2006, 10:26

In "unsteady formulation", you must choice "1st order implicit" or "2nd order implicit"

Maurosso · May 17, 2013, 17:47

Hello

I have a similar problem.

I'm doing a transient, compressible (UDF for density and speed of sound), FSI problem with the use of system coupling. I would like to simulate a pressure wave hitting an object, but i get the same error as the topic creator, even thou my fluid is compressible...help?

Will implicit time formulation, for the explicit density-based solver simulate properly the above mentioned phenomena?

thanks in advance for any help

StephanJ · October 7, 2015, 07:36

Hello,

did anyone get rid of this error? I got the same one although I want to simulate an unsteady compressible case!

sarojshah · January 14, 2021, 22:45

I also got the same error. If anyone know, please help us out

October 31, 2006, 09:10	time step incompressible flow	#1
Nicolas CAPRON Guest Posts: n/a	I want compute an unsteady incompressible flow expluctly. I gave the courant number but you obtain this message : "You cannot use global time stepping to compute unsteady incompressible flows" How to run? thanks

October 31, 2006, 10:26	Re: time step incompressible flow	#2
rassai Guest Posts: n/a	In "unsteady formulation", you must choice "1st order implicit" or "2nd order implicit"

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May 17, 2013, 17:47		#3
Maurosso New Member Marcin K Join Date: Mar 2013 Posts: 10 Rep Power: 13	Hello I have a similar problem. I'm doing a transient, compressible (UDF for density and speed of sound), FSI problem with the use of system coupling. I would like to simulate a pressure wave hitting an object, but i get the same error as the topic creator, even thou my fluid is compressible...help? Will implicit time formulation, for the explicit density-based solver simulate properly the above mentioned phenomena? thanks in advance for any help

October 7, 2015, 07:36		#4
StephanJ New Member Stephan Jäger Join Date: Oct 2015 Posts: 2 Rep Power: 0	Hello, did anyone get rid of this error? I got the same one although I want to simulate an unsteady compressible case!

January 14, 2021, 22:45		#5
sarojshah New Member saroj Join Date: Mar 2019 Posts: 1 Rep Power: 0	I also got the same error. If anyone know, please help us out