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Laval nozzle(convergent divergent) code
Posted 2011年1月21日 GMT-5 10:00 Computational Fluid Dynamics (CFD) 5 Replies
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does any one know if it is possible to simulate a laval nozzle with high pressre deifference(around 300 bar) with comsol?
the input pressure of nozzle is 300 bar(connected to a vessel) and output (connected to another vessel) increases from atmospheric pressure to equilibrium with first vessle.
both vessels are at room temprature
the input pressure of nozzle is 300 bar(connected to a vessel) and output (connected to another vessel) increases from atmospheric pressure to equilibrium with first vessle.
both vessels are at room temprature
5 Replies Last Post 2011年1月24日 GMT-5 18:31
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Posted:
1 decade ago
Hi
if you have the geoemtry, and you apply standard physics from the CFD (already implemented in COMSOL) then I see no reason whay it should not work. If you want to use specific physics, then you need to write out the PDE's what COMSOL is set up for, and much better if not uniquely w.r.t any other programme I know about. SO I would say make it a try
There are perhaps other approaches, such as Modelica based (see Modelica or MapleSim or ...) but then you talk first about algebra, thereafter numerical and you still need to find a good numerical number cruncher of you simplified model. And you have quite some algebra to type out, I do not know of readily made CFD modules for Modelica, perhps there are something ;)
You should expect some time to learn how to use COMSOL, it is an exceptional tool to do complex multiphysics, but that means also you should ideally understand the multiphysics, which means essentially: time and patience, but nothing is impossible ;)
--
Good luck
Ivar
if you have the geoemtry, and you apply standard physics from the CFD (already implemented in COMSOL) then I see no reason whay it should not work. If you want to use specific physics, then you need to write out the PDE's what COMSOL is set up for, and much better if not uniquely w.r.t any other programme I know about. SO I would say make it a try
There are perhaps other approaches, such as Modelica based (see Modelica or MapleSim or ...) but then you talk first about algebra, thereafter numerical and you still need to find a good numerical number cruncher of you simplified model. And you have quite some algebra to type out, I do not know of readily made CFD modules for Modelica, perhps there are something ;)
You should expect some time to learn how to use COMSOL, it is an exceptional tool to do complex multiphysics, but that means also you should ideally understand the multiphysics, which means essentially: time and patience, but nothing is impossible ;)
--
Good luck
Ivar
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Posted:
1 decade ago
thanks for your reply .I have the geometry but the problem is Mach number will be higher than 1 and the air will be a compressible flow.as far as I know comsol only works for Mach numbers less than 0.3. is there a plan to develope CFD module for higher Mach numbers?
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Posted:
1 decade ago
Hi
that is eally issues you should discuss directly with COMSOL via theire rep or see "contact us" above. I'm a user and not linked to COMSOL (apart that I consider myself as a fan of the tool, it's really nice to do physics again, correctly ;)
Further CFD is not my main domain, but I'm learning.
There are others here that are far more specialised than me, hopefully you can get some feedback from them too
--
Good luck
Ivar
that is eally issues you should discuss directly with COMSOL via theire rep or see "contact us" above. I'm a user and not linked to COMSOL (apart that I consider myself as a fan of the tool, it's really nice to do physics again, correctly ;)
Further CFD is not my main domain, but I'm learning.
There are others here that are far more specialised than me, hopefully you can get some feedback from them too
--
Good luck
Ivar
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Posted:
1 decade ago
Hi
I simulated a gas flow in high-voltage circuit breaker, and got mach nubers higher than 1 (1.3 as I remember).
I did it in Comsol 3.4, k-e turbulence module. But the one thing is that the gas was incompressible.
I simulated a gas flow in high-voltage circuit breaker, and got mach nubers higher than 1 (1.3 as I remember).
I did it in Comsol 3.4, k-e turbulence module. But the one thing is that the gas was incompressible.
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Posted:
1 decade ago
Actually, one of the problems I solved on my PhD research dissertation was the Laval double-throated nozzle. My work was limited to 2D, but it was viscous and turbulent (using algebraic turbulence model) and real-gas (air). I have always wanted to re-solve this problem with COMSOL (my PhD was in 1991, how great it would have been to have COMSOL back then !); or find a graduate student interested in doing this.
My suggestion is to use the PDE mode and code up the equations. There used to be a 2D Euler equation for inviscid flow if you want to solve that in v3.5a. You could use that as a guide and extend to 3D. This would not give you the viscous side of things and solving boundary layers adjacent to the wall.
I understand that compressible flow is on the way in COMSOL, along with many other new features to come.
My suggestion is to use the PDE mode and code up the equations. There used to be a 2D Euler equation for inviscid flow if you want to solve that in v3.5a. You could use that as a guide and extend to 3D. This would not give you the viscous side of things and solving boundary layers adjacent to the wall.
I understand that compressible flow is on the way in COMSOL, along with many other new features to come.
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