BCNoslipWall.c File Reference

No-slip wall boundary conditions (can also handle moving walls) More...

#include <stdlib.h>
#include <basic.h>
#include <arrayfunctions.h>
#include <boundaryconditions.h>
#include <physicalmodels/navierstokes2d.h>
#include <physicalmodels/navierstokes3d.h>

Go to the source code of this file.

Functions
int	BCNoslipWallU (void *b, void *m, int ndims, int nvars, int *size, int ghosts, double *phi, double waqt)

Detailed Description

No-slip wall boundary conditions (can also handle moving walls)

Author

Debojyoti Ghosh

Definition in file BCNoslipWall.c.

Function Documentation

int BCNoslipWallU	(	void *	b,
		void *	m,
		int	ndims,
		int	nvars,
		int *	size,
		int	ghosts,
		double *	phi,
		double	waqt
	)

Applies the no-slip wall boundary conditions: Used to simulate viscous walls. The density and pressure at the physical boundary ghost points are extrapolated from the interior, while the velocities are set such that the interpolated velocity at the boundary face is the specified wall velocity. This boundary condition is specific to the two and three dimensional Navier-Stokes systems (NavierStokes2D, NavierStokes3D).

Parameters

b	Boundary object of type DomainBoundary
m	MPI object of type MPIVariables
ndims	Number of spatial dimensions
nvars	Number of variables/DoFs per grid point
size	Integer array with the number of grid points in each spatial dimension
ghosts	Number of ghost points
phi	The solution array on which to apply the boundary condition
waqt	Current solution time

Definition at line 20 of file BCNoslipWall.c.

{
  DomainBoundary *boundary = (DomainBoundary*) b;

  int dim   = boundary->dim;
  int face  = boundary->face;

  if (ndims == 2) {

    /* create a fake physics object */
    double gamma;
    gamma = boundary->gamma;
    double inv_gamma_m1 = 1.0/(gamma-1.0);

    if (boundary->on_this_proc) {
      int bounds[ndims], indexb[ndims], indexi[ndims];
      _ArraySubtract1D_(bounds,boundary->ie,boundary->is,ndims);
      _ArraySetValue_(indexb,ndims,0);
      int done = 0;
      while (!done) {
        int p1, p2;
        _ArrayCopy1D_(indexb,indexi,ndims);
        _ArrayAdd1D_(indexi,indexi,boundary->is,ndims);
        if      (face ==  1) indexi[dim] = ghosts-1-indexb[dim];
        else if (face == -1) indexi[dim] = size[dim]-indexb[dim]-1;
        else return(1);
        _ArrayIndex1DWO_(ndims,size,indexb,boundary->is,ghosts,p1);
        _ArrayIndex1D_(ndims,size,indexi,ghosts,p2);
        
        /* flow variables in the interior */
        double rho, uvel, vvel, energy, pressure;
        double rho_gpt, uvel_gpt, vvel_gpt, energy_gpt, pressure_gpt;
        _NavierStokes2DGetFlowVar_((phi+nvars*p2),rho,uvel,vvel,energy,pressure,gamma);
        /* set the ghost point values */
        rho_gpt = rho;
        pressure_gpt = pressure;
        uvel_gpt = 2.0*boundary->FlowVelocity[0] - uvel;
        vvel_gpt = 2.0*boundary->FlowVelocity[1] - vvel;
        energy_gpt = inv_gamma_m1*pressure_gpt
                    + 0.5 * rho_gpt * (uvel_gpt*uvel_gpt + vvel_gpt*vvel_gpt);

        phi[nvars*p1+0] = rho_gpt;
        phi[nvars*p1+1] = rho_gpt * uvel_gpt;
        phi[nvars*p1+2] = rho_gpt * vvel_gpt;
        phi[nvars*p1+3] = energy_gpt;

        _ArrayIncrementIndex_(ndims,bounds,indexb,done);
      }
    }

  } else if (ndims == 3) {

    double gamma;
    gamma = boundary->gamma;
    double inv_gamma_m1 = 1.0/(gamma-1.0);

    if (boundary->on_this_proc) {
      int bounds[ndims], indexb[ndims], indexi[ndims];
      _ArraySubtract1D_(bounds,boundary->ie,boundary->is,ndims);
      _ArraySetValue_(indexb,ndims,0);
      int done = 0;
      while (!done) {
        int p1, p2;
        _ArrayCopy1D_(indexb,indexi,ndims);
        _ArrayAdd1D_(indexi,indexi,boundary->is,ndims);
        if      (face ==  1) indexi[dim] = ghosts-1-indexb[dim];
        else if (face == -1) indexi[dim] = size[dim]-indexb[dim]-1;
        else return(1);
        _ArrayIndex1DWO_(ndims,size,indexb,boundary->is,ghosts,p1);
        _ArrayIndex1D_(ndims,size,indexi,ghosts,p2);
        
        /* flow variables in the interior */
        double rho, uvel, vvel, wvel, energy, pressure;
        double rho_gpt, uvel_gpt, vvel_gpt, wvel_gpt, energy_gpt, pressure_gpt;
        _NavierStokes3DGetFlowVar_((phi+nvars*p2),_NavierStokes3D_stride_,rho,uvel,vvel,wvel,energy,pressure,gamma);
        /* set the ghost point values */
        rho_gpt = rho;
        pressure_gpt = pressure;
        uvel_gpt = 2.0*boundary->FlowVelocity[0] - uvel;
        vvel_gpt = 2.0*boundary->FlowVelocity[1] - vvel;
        wvel_gpt = 2.0*boundary->FlowVelocity[2] - wvel;
        energy_gpt = inv_gamma_m1*pressure_gpt
                    + 0.5 * rho_gpt 
                    * (uvel_gpt*uvel_gpt + vvel_gpt*vvel_gpt + wvel_gpt*wvel_gpt);

        phi[nvars*p1+0] = rho_gpt;
        phi[nvars*p1+1] = rho_gpt * uvel_gpt;
        phi[nvars*p1+2] = rho_gpt * vvel_gpt;
        phi[nvars*p1+3] = rho_gpt * wvel_gpt;
        phi[nvars*p1+4] = energy_gpt;

        _ArrayIncrementIndex_(ndims,bounds,indexb,done);
      }
    }

  }
  return(0);
}