[tsauter]

Hi all,

I am using a bouyantBoussinesq solver (LES) to model a katabatic wind flow along a slope. The surface temperature (wall) is slightly cooler than the overlying stably stratified atmosphere (see figure 1).

I like to use cyclic boundary conditions for the left and right patch, in order to get a fully developed turbulent wind field. Since the inlet and outlet are not at the same height, this causes a jump of the pressure field (see picture 2).

It is probably not possible to use a cyclic boundary condition here, or is there a way to solve this problem?

The other solution might be to rotate the frame of reference by aligning the x-axis with the slope, but I am not quite sure how to do this.

Thank you in advance
Tobias

[nimasam]

you can use cyclic BC with pressure Jump, pressure Jump can be accessed by fan type BC at inlet-outlet, search in forum about fan BC

[tsauter]

Hi Nima Sam,

Thank you very much for your response. I'll check it out.

Cheers,
Tobias

[tsauter]

Hi Niam,

I have applied the following boundary conditions to the left and right patch, respectively. But the result is still the same. Do I make something wrong?

    
left
    {
        type             fan;
        patchType     cyclic;
        jump           uniform 0;
        f                 2(100 -1.0);
        value           uniform 0;
    }
    right
    {
        type             fan;
        patchType     cyclic;
        jump            uniform 0;
        f                 2(100 -1.0);
        value           uniform 0;
    }

Thank you very much.
Tobias