About Inlet velocity Profile

[steed188]

Dear all,
I defined a inlet velocity profile using power law. Like below

Code:

template <typename T, typename S>
class TurbulentVelocity3D : public AnalyticalF3D<T,S> {

protected:
T Ratio;

public:
TurbulentVelocity3D(LBconverter<S> const& converter) : AnalyticalF3D<T,S>(3) {
Ratio = (converter.getLatticeU()) / (converter.getCharU());
this->getName() = “turbulentVelocity3d”;
};

bool operator()(T output[], const S input[]) {
T x = input[0];
T y = input[1];
T z = input[2];

output[0] =((z<1.2) ? (-1.8834*pow(z,2)+5.4808*z+2.9155):6.751) * Ratio;
output[1] =0;
output[2] =0;

return true;
};
};

I found that The inlet profile at the boundary lattice grids are a smooth law profile. But at the adjacent lattice grids, the law profile suddenly became to very irregularity sawtooth, causing the whole velocity distribution of the simulation field is like irregularity sawtooth.

My case used Smagorinsky model with Re =125000.

I’ve no idea why it was like that.

with best wishes
steed188

[Author]

Posts