ERF
Energy Research and Forecasting: An Atmospheric Modeling Code
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ERF_DiffTKEAdjustment.H
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1  // Using Deardorff (see Sullivan et al 1994)
2  // or k-eqn RANS (see Axell & Liungman 2001)
3  //
4  // Note: At this point, the thermal diffusivity ("Khv" field in ERF), the
5  // subgrid heat flux ("hfx_z" here), and the subgrid dissipation
6  // ("diss" here) have been updated by ComputeTurbulentViscosityLES --
7  // at the beginning of each timestep.
8  // The strain rate magnitude is updated at the beginning of the first
9  // RK stage only, therefore the shear production term also does not
10  // change between RK stages.
11  // The surface heat flux hfx_z(i,j,-1) is updated in MOSTStress at
12  // each RK stage, but that does not change the buoyancy production term here.
13  if (l_use_keqn && (start_comp <= RhoKE_comp) && (end_comp >= RhoKE_comp)) {
14  int qty_index = RhoKE_comp;
15  ParallelFor(bx,[=] AMREX_GPU_DEVICE (int i, int j, int k) noexcept
16  {
17  // Add Buoyancy Source
18  // where the SGS buoyancy flux tau_{theta,i} = -KH * dtheta/dx_i,
19  // such that for dtheta/dz < 0, there is a positive (upward) heat
20  // flux; the TKE buoyancy production is then
21  // B = g/theta_0 * tau_{theta,w}
22  // for a dry atmosphere.
23  // TODO: To account for moisture, the Brunt-Vaisala frequency,
24  // N^2 = g[1/theta * dtheta/dz + ...]
25  // **should** be a function of the water vapor and total water
26  // mixing ratios, depending on whether conditions are saturated or
27  // not (see the WRF model description, Skamarock et al 2019).
28  cell_rhs(i,j,k,qty_index) += l_abs_g * l_inv_theta0 * hfx_z(i,j,k);
29 
30  // TKE shear production
31  // P = -tau_ij * S_ij = 2 * mu_turb * S_ij * S_ij
32  // Note: This assumes that the horizontal and vertical diffusivities
33  // of momentum are equal
34  cell_rhs(i,j,k,qty_index) += 2.0*mu_turb(i,j,k,EddyDiff::Mom_v) * SmnSmn_a(i,j,k);
35 
36  // TKE dissipation
37  cell_rhs(i,j,k,qty_index) -= diss(i,j,k);
38  });
39  }
const int end_comp
Definition: ERF_DiffSetup.H:25
bool l_use_keqn
Definition: ERF_DiffSetup.H:15
Real l_inv_theta0
Definition: ERF_DiffSetup.H:12
Real l_abs_g
Definition: ERF_DiffSetup.H:13
#define RhoKE_comp
Definition: ERF_IndexDefines.H:38
@ Mom_v
Definition: ERF_IndexDefines.H:175