Initialize at Equilibrium

[Eric]

Dear OpenLB team,

I have a question about the initialize. As shown in cylinder2D example, function

Code:

sLattice.iniEquilibrium( superGeometry, 1, rhoF, uF )

is applied to initialize the flow field at equilibrium distribution with rhoF and uF. As far as I can see, uF is set in the code with a non-zero value. But when I checked the core code:

Code:

template<typename T, template<typename U> class Lattice>
void BlockLatticeStructure2D<T,Lattice>::iniEquilibrium(
BlockGeometryStructure2D<T>& blockGeometry, int material,
AnalyticalF2D<T,T>& rho , AnalyticalF2D<T,T>& u)
{
T physR[2]= {T(),T()};
for (int iX = 0; iX < this->_nx; iX++) {
for (int iY = 0; iY < this->_ny; iY++) {
if (blockGeometry.getMaterial(iX, iY) == material) {
blockGeometry.getPhysR(physR,iX,iY);
T uTmp[] = {T(),T()};
u(uTmp,physR);
T rhoTmp = T();
rho(&rhoTmp,physR);
get(iX,iY).iniEquilibrium(rhoTmp,uTmp);
std::cout << “iX ” << iX << ” iY ” << iY << ” rho ” << rhoTmp << ” u ” << uTmp[0] << ” ” << uTmp[1] << ” physR ” << physR[0] << ” ” << physR[1] << std::endl;
}
}
}
}

the uTmp, which is used to iniEquilibrium at cells, is always 0. May I ask is that intended or not? If so, is there any method to initialize the domain with non-zero uniform velocity?

Looking forward to hearing from you. 🙂

Best regards,
Eric

[albert.mink]

Hi Eric,

did you tried to call
sLattice.iniEquilibrium( superGeometry, 1, rhoF, uF )
with uF different to zero?

First the array is initialized by zeros.
Then it gets the value from the passed AnalyticalF2D object.

Code:

T uTmp[] = {T(),T()};
u(uTmp,physR);

So just try it.

All the best
Albert

[Eric]

Hi Albert,

You are right. I made a mistake when setting the uF.
Thank you for the swift reply!

Best regards,
Eric

[Author]

Posts