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matrix-1.0 August 4, 2007 07:16

What difference is betw. steady and unsteady simul
 
I am simulation the temperature situation of an entry hall.

My aim is to see if there is enough cooling energy to reach 26c on a hot summer day.

I simulated it in steady mode and got convergence.

Does this show me the end result of the situation in this hall, or do I need to run in also in unsteady mode ??

( I am not as lazy as it might be but my grid has 1.4 million cells and it will take ages !)

So what is the difference between steady and unsteady ?

Best regards

Matrix

msureshkumar August 4, 2007 07:59

Re: What difference is betw. steady and unsteady s
 
Steady flow analysis is independent of time effect. But in unsteady we are solving the problem with respect to time. You can simulate the whole analysis in very small time steps and multiply it by number of time steps to calculate the total time spent for the process to happen.

matrix-1.0 August 5, 2007 07:47

Re: What difference is betw. steady and unsteady s
 
Ok, but does the steady result show me the final status of the hall in reality or is it just to check if the solution is convergent, and to see the "real" status I have to do the simulation in unsteady mode ??

I already tried to run in unsteady in 1 s interval but after 7 steps the values raise to the sky and it ends with an error.

So what can the steady result tell me about the "real" status of the room ???

Many thanks Matrix

Shackal August 5, 2007 10:30

Re: What difference is betw. steady and unsteady s
 
If it does converge, with nice decreasing curves, I think you've got the end solution. If it was unsteady flow, your solution would never converge with steady solver.


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