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Old   February 26, 2013, 07:17
Post EGR mixing case
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Hiii..
In this case i am simulating air and EGR mixing in this nozzle.
i am not willing to give mass flow inlet for EGR (although i have mass flow rates for EGR1 and EGR2 inlets). I want to drive the EGR due to pressure difference in this convergent divergent nozzle.
I have attached the BC's i want to simulate. Would like you to help me with the what exact BC's to be used. If i give mass flow then pressure dsnt matches and vice versa.I have used the following BC's but of no use
a) Inlet - Mass flow , EGR's inlet - stagnation inlet, Outlet - Pressure outlet
b) Inlet - Stagnation inlet, EGR's inlet - Pressure outlet ( with target mass flow) , Outlet - pressure outlet

Physics i have used are as follows:
Ideal gas, K-e turbulence, passive scalars, segregated temp, segregated energy, all y+ etc

Help me out with this

Regards
RD
egr case1.JPG
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Old   February 26, 2013, 07:32
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siamak rahimi ardkapan
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Have you tried to use pressure outlet for both inlet and outlet?
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Good luck
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Old   February 26, 2013, 07:45
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yes i have done that too...i have mentioned the specified pressure given in the attachmnt for EGR inlet also along with this i have tried the target mass flow rate but of no use...m not getting the results as such
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Old   February 14, 2014, 14:20
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Hi,
I have the same problem, I need to set pressure + masss flow inlet and pressure outlet.

I try:
1) Inlet - Stagnation pressure (16 atm)
Outlet - mass flow rate
I get solution, where i have the same total pressure on the whole computational domain, it's wrong result
2) Inltet - Pressure outlet (16 atm)
Outlet - Pressure outlet (0 atm) with target mass flow rate
I get solution with wrong mass flow rate

Help me please with advise
Regards
Paul
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Old   February 14, 2014, 17:03
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IMO the target mass flow option is not very good in STAR-CCM+, you can get better results by coding in the BC using Newton's method in Java.
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