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April 9, 2015, 09:45 |
Transient or Steady? What do you think?
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#1 |
Member
Zhiyi Li
Join Date: Mar 2015
Location: Germany
Posts: 43
Rep Power: 11 |
Hallo everyone,
I am working on a cyclone simulation with only air inflow at the first place. Do you think I should use steady simulation or transient simulation? Since turbulence and the flow situation is changing after inflow of the air, should I use transient? I used steady af first, even though my minimum othogonal mesh quality is 0.35, I could not get a converged (residual lower than 0.001) result after 5000 times of steady simulation. So I changed to transient after 5000 times of simulation, this time I got converged situation. Do you think the method I used in the last paragraph is applicable? Or should I run the transient simulation at the first place? I am using 'Reynolds Stress Model (seven equation)'. Thank you Best Regards Litchy |
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April 9, 2015, 09:50 |
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#2 |
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subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
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i think transient a you said it is changing with time
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April 9, 2015, 16:35 |
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#3 |
Senior Member
JSM
Join Date: Mar 2009
Location: India
Posts: 192
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Hi,
We can get good converged solution with steady state itself. What boundary conditions and discretization method are you using for the simulation?
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With regards, JSM |
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April 10, 2015, 05:09 |
boundary condition and discretization method
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#4 | |
Member
Zhiyi Li
Join Date: Mar 2015
Location: Germany
Posts: 43
Rep Power: 11 |
Quote:
The discretization method I used is velocity and pressure coupling: SIMPLE Pressure: PRESTO! because of the highly swirl flow And the other discretization methods keep default. Boundary condition: Velocity_inlet: 10m/s and turbulent intensity:5%, hydraulic diameter: caulculated from the geometry, around 0.166m pressure_outlet: others keep default, turbulent intensity:5%, hydraulic diameter:0.2m The fluid is only air currently. Solver is pressure based, raynolds stress method-7 equations method. Do you think there may be some problems with my settings? Best Regards Litchy |
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April 10, 2015, 05:11 |
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#5 |
Member
Zhiyi Li
Join Date: Mar 2015
Location: Germany
Posts: 43
Rep Power: 11 |
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Tags |
fluent, steady, transient |
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