Re: About ConvectionBC

[steed188]

The outflow is defined as below. The outflow bc is on the wall of point(0, 0, 0) to point(0, 2.5, 3.8). The positive x direction is to the inner of fluid.

Code:

Vector<T, 3>outCenter(0, 1.8, 1.8) ;
T outRadius = 0.15;
Vector<T, 3> outNormal( T(1), T(), T() );
IndicatorCircle3D<T> outlet( outCenter, outNormal, outRadius);
IndicatorCylinder3D<T> outflow( outlet, 2 * converter.getLatticeL() );
superGeometry.rename( 2,4,1,outflow );

The outflow bc seems to be set correctly because if I use pressure boundary it works well in low Re flow.

Then I use the same IndicatorCircle3D to set the outflow bc with material number 4 for flux as below.

Code:

Vector<T, 3>outCenter(0,1.8,1.8) ;
T outRadius = 0.15;
Vector<T, 3> outNormal( T(1), T(), T() );
IndicatorCircle3D<T> outlet( outCenter, outNormal, outRadius);

std::list<int> materials = { 1,3,4};
SuperLatticePhysVelocityFlux3D<T, DESCRIPTOR> vFluxOutflow0( sLattice, converter, superGeometry, outlet, materials );

The mean velocity is a minus number. It means the flux is minus? And the convection bc didn’t work.
I didn’t know where is wrong.

with best
steed188