[artymk4]

I am doing compressible steady state simulation of impeller which has inlet in shape of circle at the top and outlet on sides. Static inlet zone and outlet zone are attached to rotating impeller.

Pressure at inlet is around 85,000 Pa (vacuum of 15,000 Pa). Pressure is increasing towards outlet where there is atmospheric pressure (100,000 Pa). Density looks similarly (increasing)

So temperature should be increasing from inlet to outlet, because when pressure increases, so should temperature.
But in my simulation T is 300 K at inlet (the way I set), then it's falling and reaches around 294 K at boundary of impeller and lastly it increases from 294 to 300 K in outlet zone. Expected result is that temperature only increases from inlet and reaches highest value right after air exits impeller. It should increase for at least 30 K. Temperature in outlet zone should be slightly less than max T.



Do you have any idea why my temperature behaves in opposite way?

I tried changing temperature boundary conditions but temperature was never increasing towards outlet.


My boundary conditions in file /0/T are:

internalField uniform 300;


inlet has type fixedValue
walls have type zeroGradient
I tired different types for outlet:

a)
outlet
{
type inletOutlet;
value $internalField;
inletValue $internalField;
}


b)
outlet
{
type inletOutletTotalTemperature;
gamma 1.4; //heat capacity ratio (Cp/Cv), 1.40 for dry air 20°C
inletValue $internalField; //reverse flow (inlet) value
T0 $internalField; //static temperature [K]
}


c)
outlet
{
type totalTemperature;
gamma 1.4;
T0 $internalField;
}