Hi Dear All,

If we used the D2Q13 model instead of D2Q9 model. So if the four more lattice velocities along axes. So i want to know how to write the bounce-back boundary conditions for D2Q13. I mean if we include those four extra velocities like 10-13, then how will be bounce-back boundary conditions.

Thanks if any one can explain this, it’s may be so simple but i have little confusion about one problem.

Thanks

to do bounce-back, take all unknown distribution functions (all those which have no value after streaming, because this value would come from outside the domain), and attribute the value from the opposite distribution function to them. for example, copy the value from the f with velocity (1,1) to the f with velocity (-1,-1). and copy the value from the f with velocity (2,-1) to the f with velocity (-2,1).