[sivakumar]

Dear Foamers,
I am running simulation using MRFSimpleFoam solver, the simulation has been done. But now i am comparing the results with experimental result.

the simulation result shows that inlet pressure is higher than outlet pressure.
I am not able to figure out the mistake in my case.
I have attached the U and P file for your consideration, please have a look and help to get it solved.

Thanks for your time and help,
Sivakumar

[maddalena]

Hello,
some observations:
1) before asking help, this is a must-read thread: How to give enough info to get help
2) your solver is incompressible, thus a uniform 0 value should be used. Relative pressure matters.
3) Is your U defined in agreement with the coordinate system? i.e. should the flow go in positive X direction?

mad

[sivakumar]

Hi Maddalena,
Thanks for the link, I am using MRFSimpleFoam,
Its a passage of axial flow fan,
I have defined velocity in x direction (i am not sure about this condition , how good it is)
I hope the defined pressure is fine. other boundary conditions are good I think.

the convergence not going beyond 0.001.
I have attached the figure, please have a look.
I have tried different schemes still the residual plot is same.
I have attached P and U, please have a look.

if you dont mind please give me you email id I will send my case for your consideration.


Thank you for your help and time,
Sivakumar

[dogan]

hi,
i have the same problem. I am running a centrifugal pump simulation with MRFSimpleFoam. i checked my BC's, but i couldn't find the problem. it supposed to be low pressure in the inlet (suction), and high pressure in the outlet, but the results are showing the opposite.


here is the U:


dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 1.485);

boundaryField
{
Wall_0
{
type fixedValue;
value uniform (0 0 0);
}

Dummy_4
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Inlet_7
{
type fixedValue;
value uniform (0 0 1.485);
}
Wall_8
{
type fixedValue;
value uniform (0 0 0);
}
Dummy_10
{
type cyclicGgi;
value $internalField;
}
Dummy_11
{
type cyclicGgi;
value $internalField;
}
Dummy_12
{
type cyclicGgi;
value $internalField;
}
Dummy_13
{
type cyclicGgi;
value $internalField;
}
Dummy_14
{
type cyclicGgi;
value $internalField;
}
Dummy_15
{
type cyclicGgi;
value $internalField;
}
Dummy_16
{
type cyclicGgi;
value $internalField;
}
Dummy_17
{
type cyclicGgi;
value $internalField;
}
Dummy_18
{
type cyclicGgi;
value $internalField;
}
Dummy_19
{
type cyclicGgi;
value $internalField;
}
Dummy_20
{
type cyclicGgi;
value $internalField;
}
Dummy_21
{
type cyclicGgi;
value $internalField;
}
Dummy_24
{
type cyclicGgi;
value $internalField;
}
Dummy_25
{
type cyclicGgi;
value $internalField;
}
Dummy_26
{
type cyclicGgi;
value $internalField;
}
Dummy_27
{
type cyclicGgi;
value $internalField;
}
Wall_30
{
type fixedValue;
value uniform (0 0 0);
}
Inlet_31
{
type fixedValue;
value uniform (0 0 1.485);
}
Wall_32
{
type fixedValue;
value uniform (0 0 0);
}
Dummy_38
{
type cyclicGgi;
value $internalField;
}
Wall_39
{
type fixedValue;
value uniform (0 0 0);
}
Wall_48
{
type fixedValue;
value uniform (0 0 0);
}
Outlet_61
{
type zeroGradient;

}
Dummy_GGI_1
{
type cyclicGgi;
value $internalField;
}
Dummy_GGI_2
{
type cyclicGgi;
value $internalField;
}
Interface_22_23
{
type cyclicGgi;
value $internalField;
}
Interface_28_29
{
type cyclicGgi;
value $internalField;
}
Interface_36_37
{
type cyclicGgi;
value $internalField;
}
Interface_40_41
{
type cyclicGgi;
value $internalField;
}
Dummy_2_6_9
{
type cyclicGgi;
value $internalField;
}
Dummy_33_34_35
{
type cyclicGgi;
value $internalField;
}



and the p:


dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
Wall_0
{
type zeroGradient;

}

Dummy_4
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_10
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_11
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_12
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_13
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_14
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_15
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_16
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_17
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_18
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_19
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_20
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_21
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_24
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_25
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_26
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_27
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Wall_30
{
type zeroGradient;

}

Inlet_31
{
type zeroGradient;

}

Wall_32
{
type zeroGradient;

}

Dummy_38
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Wall_39
{
type zeroGradient;

}

Wall_48
{
type zeroGradient;

}

Outlet_61
{
type fixedValue;
value $internalField;
}

Dummy_GGI_1
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_GGI_2
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Interface_22_23
{
type cyclicGgi;
value $internalField;
}

Interface_28_29
{
type cyclicGgi;
value $internalField;
}

Interface_36_37
{
type cyclicGgi;
value $internalField;
}

Interface_40_41
{
type cyclicGgi;
value $internalField;
}

Dummy_2_6_9
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Dummy_33_34_35
{
type cyclicGgi;
//inletValue $internalField;
value $internalField;
}

Inlet_7
{
type zeroGradient;

}

Wall_8
{
type zeroGradient;
//value $internalField
}



van you see what the problem is?