Subdomain different timestep

diggian · January 24, 2018, 06:11

I'm simulating a supersonic flow inside a very big volume (3000 m $^{3}$ ). The jet comes from a pressure of 80 bar and reaches the big volume at a pressure of 0.2 bar. I'm simulating a 2D section of the volume and the simulation works, but due to the very big dimensions, the computational time is very huge. That is why I was wondering if there is a way to divide the domain in two different subdomains, I mean, I want to study separately the release domain and the diffuse domain. I want to use the release in a small domain with a very fine mesh and use the results of this simulations as boundary conditions of the diffusion domain (with bigger mesh base size and bigger timestep). Is it possible? I'm studying a transient problem...please help me <3
Thanks!

fluid23 · January 24, 2018, 13:23

Sounds like you are wanting to do a co-simulation. From the user manual:

'STAR-CCM+ allows you to couple two running simulations together in a co-simulation analysis. The STAR-CCM+ to STAR-CCM+ co-simulation capability targets simulations involving conjugate heat transfer (CHT), fluid-structure interaction (FSI) or exchange of scalar/vector fields across a coupling boundary.'

January 24, 2018, 06:11	Subdomain different timestep	#1
diggian New Member Jean-Luc Join Date: Oct 2017 Location: Turin, Italy Posts: 5 Rep Power: 9	I'm simulating a supersonic flow inside a very big volume (3000 m $^{3}$ ). The jet comes from a pressure of 80 bar and reaches the big volume at a pressure of 0.2 bar. I'm simulating a 2D section of the volume and the simulation works, but due to the very big dimensions, the computational time is very huge. That is why I was wondering if there is a way to divide the domain in two different subdomains, I mean, I want to study separately the release domain and the diffuse domain. I want to use the release in a small domain with a very fine mesh and use the results of this simulations as boundary conditions of the diffusion domain (with bigger mesh base size and bigger timestep). Is it possible? I'm studying a transient problem...please help me <3 Thanks!

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January 24, 2018, 13:23		#2
fluid23 Senior Member Matt Join Date: Aug 2014 Posts: 947 Rep Power: 18	Sounds like you are wanting to do a co-simulation. From the user manual: 'STAR-CCM+ allows you to couple two running simulations together in a co-simulation analysis. The STAR-CCM+ to STAR-CCM+ co-simulation capability targets simulations involving conjugate heat transfer (CHT), fluid-structure interaction (FSI) or exchange of scalar/vector fields across a coupling boundary.'