deardorff_cpu.f90

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module deardorff_cpu
  use utils, only : neko_error
  use num_types, only : rp
  use field_list, only : field_list_t
  use scratch_registry, only : neko_scratch_registry
  use registry, only : neko_registry
  use field, only : field_t
  use operators, only : strain_rate
  use coefs, only : coef_t
  use gs_ops, only : gs_op_add
  use math, only : col2, neko_eps
  use operators, only : grad
  implicit none
  private
 
  public :: deardorff_compute_cpu
 
contains
 
  subroutine deardorff_compute_cpu(t, tstep, coef, &
       temperature_field_name, TKE_field_name, &
       nut, temperature_alphat, &
       TKE_alphat, TKE_source, &
       delta, c_k, T0, g)
    real(kind=rp), intent(in) :: t
    integer, intent(in) :: tstep
    type(coef_t), intent(in) :: coef
    character(len=*), intent(in) :: temperature_field_name
    character(len=*), intent(in) :: tke_field_name
    type(field_t), intent(inout) :: nut, temperature_alphat
    type(field_t), intent(inout) :: tke_alphat, tke_source
    type(field_t), intent(in) :: delta
    real(kind=rp), intent(in) :: c_k, t0, g(3)
    type(field_t), pointer :: tke, temperature
    type(field_t), pointer :: dtdx, dtdy, dtdz
    type(field_t), pointer :: u, v, w
    real(kind=rp):: s11, s22, s33, s12, s13, s23
    type(field_t), pointer :: a11, a12, a13, a21, a22, a23, a31, a32, a33
    real(kind=rp) :: shear, buoyancy, dissipation
    integer :: temp_indices(12)
    real(kind=rp) :: l, n2
    integer :: e, i
 
    tke => neko_registry%get_field_by_name(tke_field_name)
    temperature => neko_registry%get_field_by_name(temperature_field_name)
 
    u => neko_registry%get_field_by_name("u")
    v => neko_registry%get_field_by_name("v")
    w => neko_registry%get_field_by_name("w")
 
    call neko_scratch_registry%request_field(dtdx, temp_indices(1), .false.)
    call neko_scratch_registry%request_field(dtdy, temp_indices(2), .false.)
    call neko_scratch_registry%request_field(dtdz, temp_indices(3), .false.)
 
    ! Calculate vertical temperature gradients
    call grad(dtdx%x, dtdy%x, dtdz%x, temperature%x, coef)
 
    call coef%gs_h%op(dtdx, gs_op_add)
    call coef%gs_h%op(dtdy, gs_op_add)
    call coef%gs_h%op(dtdz, gs_op_add)
    call col2(dtdx%x, coef%mult, nut%dof%size())
    call col2(dtdy%x, coef%mult, nut%dof%size())
    call col2(dtdz%x, coef%mult, nut%dof%size())
 
    ! Compute velocity gradients
    call neko_scratch_registry%request_field(a11, temp_indices(4), .false.)
    call neko_scratch_registry%request_field(a12, temp_indices(5), .false.)
    call neko_scratch_registry%request_field(a13, temp_indices(6), .false.)
    call neko_scratch_registry%request_field(a21, temp_indices(7), .false.)
    call neko_scratch_registry%request_field(a22, temp_indices(8), .false.)
    call neko_scratch_registry%request_field(a23, temp_indices(9), .false.)
    call neko_scratch_registry%request_field(a31, temp_indices(10), .false.)
    call neko_scratch_registry%request_field(a32, temp_indices(11), .false.)
    call neko_scratch_registry%request_field(a33, temp_indices(12), .false.)
 
    call grad(a11%x, a12%x, a13%x, u%x, coef)
    call grad(a21%x, a22%x, a23%x, v%x, coef)
    call grad(a31%x, a32%x, a33%x, w%x, coef)
 
    call coef%gs_h%op(a11, gs_op_add)
    call coef%gs_h%op(a12, gs_op_add)
    call coef%gs_h%op(a13, gs_op_add)
    call coef%gs_h%op(a21, gs_op_add)
    call coef%gs_h%op(a22, gs_op_add)
    call coef%gs_h%op(a23, gs_op_add)
    call coef%gs_h%op(a31, gs_op_add)
    call coef%gs_h%op(a32, gs_op_add)
    call coef%gs_h%op(a33, gs_op_add)
 
    call col2(a11%x, coef%mult, nut%dof%size())
    call col2(a12%x, coef%mult, nut%dof%size())
    call col2(a13%x, coef%mult, nut%dof%size())
    call col2(a21%x, coef%mult, nut%dof%size())
    call col2(a22%x, coef%mult, nut%dof%size())
    call col2(a23%x, coef%mult, nut%dof%size())
    call col2(a31%x, coef%mult, nut%dof%size())
    call col2(a32%x, coef%mult, nut%dof%size())
    call col2(a33%x, coef%mult, nut%dof%size())
 
    ! Determine static stability and length scale
    do concurrent(i = 1:coef%dof%size())
       ! correct TKE if negative or nearly zero
       if (tke%x(i,1,1,1) .lt. neko_eps) then
          tke%x(i,1,1,1) = neko_eps
       end if
 
       n2 = (dtdx%x(i,1,1,1) * g(1) + &
            dtdy%x(i,1,1,1) * g(2) + &
            dtdz%x(i,1,1,1) * g(3)) / t0
       if (n2 .gt. 0.0_rp) then
          l = 0.76_rp * sqrt(tke%x(i,1,1,1) / n2)
          l = min(l, delta%x(i,1,1,1))
       else
          l = delta%x(i,1,1,1)
       end if
 
       ! Eddy viscosity
       nut%x(i,1,1,1) = c_k * l * sqrt(tke%x(i,1,1,1))
 
       ! Eddy diffusivity for temperature
       temperature_alphat%x(i,1,1,1) = (1.0_rp + 2.0_rp * l/delta%x(i,1,1,1)) &
            * nut%x(i,1,1,1)
       tke_alphat%x(i,1,1,1) = 2.0_rp * nut%x(i,1,1,1) ! Eddy diffusivity of TKE
 
       s11 = a11%x(i,1,1,1) + a11%x(i,1,1,1)
       s22 = a22%x(i,1,1,1) + a22%x(i,1,1,1)
       s33 = a33%x(i,1,1,1) + a33%x(i,1,1,1)
       s12 = a12%x(i,1,1,1) + a21%x(i,1,1,1)
       s13 = a13%x(i,1,1,1) + a31%x(i,1,1,1)
       s23 = a23%x(i,1,1,1) + a32%x(i,1,1,1)
       ! Shear term
       shear = nut%x(i,1,1,1) &
            * (s11*a11%x(i,1,1,1) &
            + s12*a12%x(i,1,1,1) &
            + s13*a13%x(i,1,1,1) &
            + s12*a21%x(i,1,1,1) &
            + s22*a22%x(i,1,1,1) &
            + s23*a23%x(i,1,1,1) &
            + s13*a31%x(i,1,1,1) &
            + s23*a32%x(i,1,1,1) &
            + s33*a33%x(i,1,1,1))
 
       ! Buoyancy term
       buoyancy = -(g(1) * dtdx%x(i,1,1,1) + &
            g(2) * dtdy%x(i,1,1,1) + &
            g(3) * dtdz%x(i,1,1,1)) / t0 * temperature_alphat%x(i,1,1,1)
 
       dissipation = -(0.19_rp + 0.74_rp * l/ delta%x(i,1,1,1)) &
            * sqrt(tke%x(i,1,1,1)*tke%x(i,1,1,1)*tke%x(i,1,1,1)) &
            / l
 
       ! Add three source terms together
       tke_source%x(i,1,1,1) = shear + buoyancy + dissipation
    end do
 
    call neko_scratch_registry%relinquish_field(temp_indices)
  end subroutine deardorff_compute_cpu
 
end module deardorff_cpu