Exemple #1
0
PetscErrorCode StokesExactSolution(Stokes *s)
{
  PetscInt       row, start, end, i, j;
  PetscScalar    val;
  Vec            y0,y1;
  PetscErrorCode ierr;

  PetscFunctionBeginUser;
  /* velocity part */
  ierr = VecGetSubVector(s->y, s->isg[0], &y0);CHKERRQ(ierr);
  ierr = VecGetOwnershipRange(y0, &start, &end);CHKERRQ(ierr);
  for (row = start; row < end; row++) {
    ierr = StokesGetPosition(s, row,&i,&j);CHKERRQ(ierr);
    if (row < s->nx*s->ny) {
      val = StokesExactVelocityX(j*s->hy+s->hy/2);
    } else {
      val = 0;
    }
    ierr = VecSetValue(y0, row, val, INSERT_VALUES);CHKERRQ(ierr);
  }
  ierr = VecRestoreSubVector(s->y, s->isg[0], &y0);CHKERRQ(ierr);

  /* pressure part */
  ierr = VecGetSubVector(s->y, s->isg[1], &y1);CHKERRQ(ierr);
  ierr = VecGetOwnershipRange(y1, &start, &end);CHKERRQ(ierr);
  for (row = start; row < end; row++) {
    ierr = StokesGetPosition(s, row, &i, &j);CHKERRQ(ierr);
    val  = StokesExactPressure(i*s->hx+s->hx/2);
    ierr = VecSetValue(y1, row, val, INSERT_VALUES);CHKERRQ(ierr);
  }
  ierr = VecRestoreSubVector(s->y, s->isg[1], &y1);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Exemple #2
0
PetscErrorCode StokesRhs(Stokes *s)
{
  PetscInt       row, start, end, i, j;
  PetscScalar    val;
  Vec            b0,b1;
  PetscErrorCode ierr;

  PetscFunctionBeginUser;
  /* velocity part */
  ierr = VecGetSubVector(s->b, s->isg[0], &b0);CHKERRQ(ierr);
  ierr = VecGetOwnershipRange(b0, &start, &end);CHKERRQ(ierr);
  for (row = start; row < end; row++) {
    ierr = StokesGetPosition(s, row, &i, &j);CHKERRQ(ierr);
    if (row < s->nx*s->ny) {
      ierr = StokesRhsMomX(s, i, j, &val);CHKERRQ(ierr);
    } else if (row < 2*s->nx*s->ny) {
      ierr = StokesRhsMomY(s, i, j, &val);CHKERRQ(ierr);
    }
    ierr = VecSetValue(b0, row, val, INSERT_VALUES);CHKERRQ(ierr);
  }
  ierr = VecRestoreSubVector(s->b, s->isg[0], &b0);CHKERRQ(ierr);

  /* pressure part */
  ierr = VecGetSubVector(s->b, s->isg[1], &b1);CHKERRQ(ierr);
  ierr = VecGetOwnershipRange(b1, &start, &end);CHKERRQ(ierr);
  for (row = start; row < end; row++) {
    ierr = StokesGetPosition(s, row, &i, &j);CHKERRQ(ierr);
    ierr = StokesRhsMass(s, i, j, &val);CHKERRQ(ierr);
    ierr = VecSetValue(b1, row, val, INSERT_VALUES);CHKERRQ(ierr);
  }
  ierr = VecRestoreSubVector(s->b, s->isg[1], &b1);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Exemple #3
0
PetscErrorCode StokesSetupMatBlock01(Stokes *s)
{
  PetscInt       row, start, end, size, i, j;
  PetscInt       cols[5];
  PetscScalar    vals[5];
  PetscErrorCode ierr;

  PetscFunctionBeginUser;
  /* A[1] is 2N-by-N */
  ierr = MatCreate(PETSC_COMM_WORLD, &s->subA[1]);CHKERRQ(ierr);
  ierr = MatSetOptionsPrefix(s->subA[1],"a01_");
  ierr = MatSetSizes(s->subA[1],PETSC_DECIDE,PETSC_DECIDE,2*s->nx*s->ny,s->nx*s->ny);CHKERRQ(ierr);
  ierr = MatSetType(s->subA[1],MATMPIAIJ);CHKERRQ(ierr);
  ierr = MatMPIAIJSetPreallocation(s->subA[1],5,NULL,5,NULL);CHKERRQ(ierr);
  ierr = MatGetOwnershipRange(s->subA[1],&start,&end);CHKERRQ(ierr);

  ierr = MatSetOption(s->subA[1],MAT_IGNORE_ZERO_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);

  for (row = start; row < end; row++) {
    ierr = StokesGetPosition(s, row, &i, &j);CHKERRQ(ierr);
    /* first part: rows 0 to (nx*ny-1) */
    if (row < s->nx*s->ny) {
      ierr = StokesStencilGradientX(s, i, j, &size, cols, vals);CHKERRQ(ierr);
    }
    /* second part: rows (nx*ny) to (2*nx*ny-1) */
    else {
      ierr = StokesStencilGradientY(s, i, j, &size, cols, vals);CHKERRQ(ierr);
    }
    ierr = MatSetValues(s->subA[1], 1, &row, size, cols, vals, INSERT_VALUES);CHKERRQ(ierr);
  }
  ierr = MatAssemblyBegin(s->subA[1], MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
  ierr = MatAssemblyEnd(s->subA[1], MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Exemple #4
0
PetscErrorCode StokesSetupMatBlock00(Stokes *s)
{
  PetscInt       row, start, end, size, i, j;
  PetscInt       cols[5];
  PetscScalar    vals[5];
  PetscErrorCode ierr;

  PetscFunctionBeginUser;
  /* A[0] is 2N-by-2N */
  ierr = MatCreate(PETSC_COMM_WORLD,&s->subA[0]);CHKERRQ(ierr);
  ierr = MatSetOptionsPrefix(s->subA[0],"a00_");CHKERRQ(ierr);
  ierr = MatSetSizes(s->subA[0],PETSC_DECIDE,PETSC_DECIDE,2*s->nx*s->ny,2*s->nx*s->ny);CHKERRQ(ierr);
  ierr = MatSetType(s->subA[0],MATMPIAIJ);CHKERRQ(ierr);
  ierr = MatMPIAIJSetPreallocation(s->subA[0],5,NULL,5,NULL);CHKERRQ(ierr);
  ierr = MatGetOwnershipRange(s->subA[0], &start, &end);CHKERRQ(ierr);

  for (row = start; row < end; row++) {
    ierr = StokesGetPosition(s, row, &i, &j);CHKERRQ(ierr);
    /* first part: rows 0 to (nx*ny-1) */
    ierr = StokesStencilLaplacian(s, i, j, &size, cols, vals);CHKERRQ(ierr);
    /* second part: rows (nx*ny) to (2*nx*ny-1) */
    if (row >= s->nx*s->ny) {
      for (i = 0; i < 5; i++) cols[i] = cols[i] + s->nx*s->ny;
    }
    for (i = 0; i < 5; i++) vals[i] = -1.0*vals[i]; /* dynamic viscosity coef mu=-1 */
    ierr = MatSetValues(s->subA[0], 1, &row, size, cols, vals, INSERT_VALUES);CHKERRQ(ierr);
  }
  ierr = MatAssemblyBegin(s->subA[0], MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
  ierr = MatAssemblyEnd(s->subA[0], MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Exemple #5
0
PetscErrorCode StokesSetupMatFp(Stokes *s)
{
  PetscInt       row, start, end, size, i, j;
  PetscInt       cols[5];
  PetscScalar    vals[5];
  PetscErrorCode ierr;

  PetscFunctionBeginUser;
  // Fp is N-by-N 
  ierr = MatCreate(PETSC_COMM_WORLD,&s->Fp);CHKERRQ(ierr);
  ierr = MatSetOptionsPrefix(s->Fp,"Fp_");CHKERRQ(ierr);
  ierr = MatSetSizes(s->Fp,PETSC_DECIDE,PETSC_DECIDE,s->nx*s->ny,s->nx*s->ny);CHKERRQ(ierr);
  ierr = MatSetType(s->Fp,MATMPIAIJ);CHKERRQ(ierr);
  ierr = MatMPIAIJSetPreallocation(s->Fp,5,NULL,5,NULL);CHKERRQ(ierr);
  ierr = MatGetOwnershipRange(s->Fp, &start, &end);CHKERRQ(ierr);

  for (row = start; row < end; row++) {
    ierr = StokesGetPosition(s, row, &i, &j);CHKERRQ(ierr);
    ierr = StokesStencilLaplacian(s, i, j, &size, cols, vals);CHKERRQ(ierr);
    for (i = 0; i < 5; i++) vals[i] = -1.0*vals[i]; //* dynamic viscosity coef mu=-1 
    ierr = MatSetValues(s->Fp, 1, &row, size, cols, vals, INSERT_VALUES);CHKERRQ(ierr);
  }
  ierr = MatAssemblyBegin(s->Fp, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
  ierr = MatAssemblyEnd(s->Fp, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}