1 // Copyright (c) 2017-2024, Lawrence Livermore National Security, LLC and other CEED contributors. 2 // All Rights Reserved. See the top-level LICENSE and NOTICE files for details. 3 // 4 // SPDX-License-Identifier: BSD-2-Clause 5 // 6 // This file is part of CEED: http://github.com/ceed 7 8 /// @file 9 /// Utility functions for setting up Blasius Boundary Layer 10 11 #include "../qfunctions/blasius.h" 12 13 #include <ceed.h> 14 #include <petscdm.h> 15 #include <petscdt.h> 16 17 #include <navierstokes.h> 18 #include "stg_shur14.h" 19 20 PetscErrorCode CompressibleBlasiusResidual(SNES snes, Vec X, Vec R, void *ctx) { 21 const BlasiusContext blasius = (BlasiusContext)ctx; 22 const PetscScalar *Tf, *Th; // Chebyshev coefficients 23 PetscScalar *r, f[4], h[4]; 24 PetscInt N = blasius->n_cheb; 25 State S_infty = blasius->S_infty; 26 CeedScalar U_infty = Norm3(S_infty.Y.velocity); 27 28 PetscFunctionBeginUser; 29 PetscScalar Ma = Mach(&blasius->newtonian_ctx, S_infty.Y.temperature, U_infty), Pr = Prandtl(&blasius->newtonian_ctx), 30 gamma = HeatCapacityRatio(&blasius->newtonian_ctx); 31 32 PetscCall(VecGetArrayRead(X, &Tf)); 33 Th = Tf + N; 34 PetscCall(VecGetArray(R, &r)); 35 36 // Left boundary conditions f = f' = 0 37 ChebyshevEval(N, Tf, -1., blasius->eta_max, f); 38 r[0] = f[0]; 39 r[1] = f[1]; 40 41 // f - right end boundary condition 42 ChebyshevEval(N, Tf, 1., blasius->eta_max, f); 43 r[2] = f[1] - 1.; 44 45 for (int i = 0; i < N - 3; i++) { 46 ChebyshevEval(N, Tf, blasius->X[i], blasius->eta_max, f); 47 ChebyshevEval(N - 1, Th, blasius->X[i], blasius->eta_max, h); 48 // mu and rho generally depend on h. 49 // We naively assume constant mu. 50 // For an ideal gas at constant pressure, density is inversely proportional to enthalpy. 51 // The *_tilde values are *relative* to their freestream values, and we proved first derivatives here. 52 const PetscScalar mu_tilde[2] = {1, 0}; 53 const PetscScalar rho_tilde[2] = {1 / h[0], -h[1] / PetscSqr(h[0])}; 54 const PetscScalar mu_rho_tilde[2] = { 55 mu_tilde[0] * rho_tilde[0], 56 mu_tilde[1] * rho_tilde[0] + mu_tilde[0] * rho_tilde[1], 57 }; 58 r[3 + i] = 2 * (mu_rho_tilde[0] * f[3] + mu_rho_tilde[1] * f[2]) + f[2] * f[0]; 59 r[N + 2 + i] = (mu_rho_tilde[0] * h[2] + mu_rho_tilde[1] * h[1]) + Pr * f[0] * h[1] + Pr * (gamma - 1) * mu_rho_tilde[0] * PetscSqr(Ma * f[2]); 60 } 61 62 // h - left end boundary condition 63 ChebyshevEval(N - 1, Th, -1., blasius->eta_max, h); 64 r[N] = h[0] - blasius->T_wall / S_infty.Y.temperature; 65 66 // h - right end boundary condition 67 ChebyshevEval(N - 1, Th, 1., blasius->eta_max, h); 68 r[N + 1] = h[0] - 1.; 69 70 // Restore vectors 71 PetscCall(VecRestoreArrayRead(X, &Tf)); 72 PetscCall(VecRestoreArray(R, &r)); 73 PetscFunctionReturn(PETSC_SUCCESS); 74 } 75 76 PetscErrorCode ComputeChebyshevCoefficients(BlasiusContext blasius) { 77 SNES snes; 78 Vec sol, res; 79 PetscReal *w; 80 PetscInt N = blasius->n_cheb; 81 SNESConvergedReason reason; 82 const PetscScalar *cheb_coefs; 83 84 PetscFunctionBeginUser; 85 // Allocate memory 86 PetscCall(PetscMalloc2(N - 3, &blasius->X, N - 3, &w)); 87 PetscCall(PetscDTGaussQuadrature(N - 3, -1., 1., blasius->X, w)); 88 89 // Snes solve 90 PetscCall(SNESCreate(PETSC_COMM_SELF, &snes)); 91 PetscCall(VecCreate(PETSC_COMM_SELF, &sol)); 92 PetscCall(VecSetSizes(sol, PETSC_DECIDE, 2 * N - 1)); 93 PetscCall(VecSetFromOptions(sol)); 94 // Constant relative enthalpy 1 as initial guess 95 PetscCall(VecSetValue(sol, N, 1., INSERT_VALUES)); 96 PetscCall(VecDuplicate(sol, &res)); 97 PetscCall(SNESSetFunction(snes, res, CompressibleBlasiusResidual, blasius)); 98 PetscCall(SNESSetOptionsPrefix(snes, "chebyshev_")); 99 PetscCall(SNESSetFromOptions(snes)); 100 PetscCall(SNESSolve(snes, NULL, sol)); 101 PetscCall(SNESGetConvergedReason(snes, &reason)); 102 PetscCheck(reason >= 0, PETSC_COMM_WORLD, PETSC_ERR_CONV_FAILED, "The Chebyshev solve failed.\n"); 103 104 // Assign Chebyshev coefficients 105 PetscCall(VecGetArrayRead(sol, &cheb_coefs)); 106 for (int i = 0; i < N; i++) blasius->Tf_cheb[i] = cheb_coefs[i]; 107 for (int i = 0; i < N - 1; i++) blasius->Th_cheb[i] = cheb_coefs[i + N]; 108 109 // Destroy objects 110 PetscCall(PetscFree2(blasius->X, w)); 111 PetscCall(VecDestroy(&sol)); 112 PetscCall(VecDestroy(&res)); 113 PetscCall(SNESDestroy(&snes)); 114 PetscFunctionReturn(PETSC_SUCCESS); 115 } 116 117 static PetscErrorCode GetYNodeLocs(const MPI_Comm comm, const char path[PETSC_MAX_PATH_LEN], PetscReal **pynodes, PetscInt *nynodes) { 118 int ndims, dims[2] = {0.}; 119 FILE *fp; 120 const PetscInt char_array_len = 512; 121 char line[char_array_len]; 122 PetscReal *node_locs; 123 124 PetscFunctionBeginUser; 125 PetscCall(PetscFOpen(comm, path, "r", &fp)); 126 PetscCall(PetscSynchronizedFGets(comm, fp, char_array_len, line)); 127 { 128 char **array; 129 130 PetscCall(PetscStrToArray(line, ' ', &ndims, &array)); 131 for (PetscInt i = 0; i < ndims; i++) dims[i] = atoi(array[i]); 132 PetscCall(PetscStrToArrayDestroy(ndims, array)); 133 } 134 if (ndims < 2) dims[1] = 1; // Assume 1 column of data is not otherwise specified 135 *nynodes = dims[0]; 136 PetscCall(PetscMalloc1(*nynodes, &node_locs)); 137 138 for (PetscInt i = 0; i < dims[0]; i++) { 139 char **array; 140 141 PetscCall(PetscSynchronizedFGets(comm, fp, char_array_len, line)); 142 PetscCall(PetscStrToArray(line, ' ', &ndims, &array)); 143 PetscCheck(ndims == dims[1], comm, PETSC_ERR_FILE_UNEXPECTED, 144 "Line %" PetscInt_FMT " of %s does not contain correct number of columns (%d instead of %d)", i, path, ndims, dims[1]); 145 146 node_locs[i] = (PetscReal)atof(array[0]); 147 PetscCall(PetscStrToArrayDestroy(ndims, array)); 148 } 149 PetscCall(PetscFClose(comm, fp)); 150 *pynodes = node_locs; 151 PetscFunctionReturn(PETSC_SUCCESS); 152 } 153 154 /* \brief Modify the domain and mesh for blasius 155 * 156 * Modifies mesh such that `N` elements are within `refine_height` with a geometric growth ratio of `growth`. Excess elements are then distributed 157 * linearly in logspace to the top surface. 158 * 159 * The top surface is also angled downwards, so that it may be used as an outflow. 160 * It's angle is controlled by `top_angle` (in units of degrees). 161 * 162 * If `node_locs` is not NULL, then the nodes will be placed at `node_locs` locations. 163 * If it is NULL, then the modified coordinate values will be set in the array, along with `num_node_locs`. 164 */ 165 static PetscErrorCode ModifyMesh(MPI_Comm comm, DM dm, PetscInt dim, PetscReal growth, PetscInt N, PetscReal refine_height, PetscReal top_angle, 166 PetscReal *node_locs[], PetscInt *num_node_locs) { 167 PetscInt narr, ncoords; 168 PetscReal domain_min[3], domain_max[3], domain_size[3]; 169 PetscScalar *arr_coords; 170 Vec vec_coords; 171 172 PetscFunctionBeginUser; 173 PetscReal angle_coeff = tan(top_angle * (M_PI / 180)); 174 // Get domain boundary information 175 PetscCall(DMGetBoundingBox(dm, domain_min, domain_max)); 176 for (PetscInt i = 0; i < 3; i++) domain_size[i] = domain_max[i] - domain_min[i]; 177 178 // Get coords array from DM 179 PetscCall(DMGetCoordinatesLocal(dm, &vec_coords)); 180 PetscCall(VecGetLocalSize(vec_coords, &narr)); 181 PetscCall(VecGetArray(vec_coords, &arr_coords)); 182 183 PetscScalar(*coords)[dim] = (PetscScalar(*)[dim])arr_coords; 184 ncoords = narr / dim; 185 186 // Get mesh information 187 PetscInt nmax = 3, faces[3]; 188 PetscCall(PetscOptionsGetIntArray(NULL, NULL, "-dm_plex_box_faces", faces, &nmax, NULL)); 189 // Get element size of the box mesh, for indexing each node 190 const PetscReal dybox = domain_size[1] / faces[1]; 191 192 if (!*node_locs) { 193 // Calculate the first element height 194 PetscReal dy1 = refine_height * (growth - 1) / (pow(growth, N) - 1); 195 196 // Calculate log of sizing outside BL 197 PetscReal logdy = (log(domain_max[1]) - log(refine_height)) / (faces[1] - N); 198 199 *num_node_locs = faces[1] + 1; 200 PetscReal *temp_node_locs; 201 PetscCall(PetscMalloc1(*num_node_locs, &temp_node_locs)); 202 203 for (PetscInt i = 0; i < ncoords; i++) { 204 PetscInt y_box_index = round(coords[i][1] / dybox); 205 if (y_box_index <= N) { 206 coords[i][1] = 207 (1 - (coords[i][0] - domain_min[0]) * angle_coeff / domain_max[1]) * dy1 * (pow(growth, coords[i][1] / dybox) - 1) / (growth - 1); 208 } else { 209 PetscInt j = y_box_index - N; 210 coords[i][1] = (1 - (coords[i][0] - domain_min[0]) * angle_coeff / domain_max[1]) * exp(log(refine_height) + logdy * j); 211 } 212 if (coords[i][0] == domain_min[0] && coords[i][2] == domain_min[2]) temp_node_locs[y_box_index] = coords[i][1]; 213 } 214 215 *node_locs = temp_node_locs; 216 } else { 217 PetscCheck(*num_node_locs >= faces[1] + 1, comm, PETSC_ERR_FILE_UNEXPECTED, 218 "The y_node_locs_path has too few locations; There are %" PetscInt_FMT " + 1 nodes, but only %" PetscInt_FMT " locations given", 219 faces[1] + 1, *num_node_locs); 220 if (*num_node_locs > faces[1] + 1) { 221 PetscCall(PetscPrintf(comm, 222 "WARNING: y_node_locs_path has more locations (%" PetscInt_FMT ") " 223 "than the mesh has nodes (%" PetscInt_FMT "). This maybe unintended.\n", 224 *num_node_locs, faces[1] + 1)); 225 } 226 PetscScalar max_y = (*node_locs)[faces[1]]; 227 228 for (PetscInt i = 0; i < ncoords; i++) { 229 // Determine which y-node we're at 230 PetscInt y_box_index = round(coords[i][1] / dybox); 231 coords[i][1] = (1 - (coords[i][0] - domain_min[0]) * angle_coeff / max_y) * (*node_locs)[y_box_index]; 232 } 233 } 234 235 PetscCall(VecRestoreArray(vec_coords, &arr_coords)); 236 PetscCall(DMSetCoordinatesLocal(dm, vec_coords)); 237 PetscFunctionReturn(PETSC_SUCCESS); 238 } 239 240 PetscErrorCode NS_BLASIUS(ProblemData problem, DM dm, void *ctx, SimpleBC bc) { 241 User user = *(User *)ctx; 242 MPI_Comm comm = user->comm; 243 Ceed ceed = user->ceed; 244 PetscBool use_stg = PETSC_FALSE; 245 BlasiusContext blasius_ctx; 246 NewtonianIdealGasContext newtonian_ig_ctx; 247 CeedQFunctionContext blasius_context; 248 249 PetscFunctionBeginUser; 250 PetscCall(NS_NEWTONIAN_IG(problem, dm, ctx, bc)); 251 PetscCall(PetscCalloc1(1, &blasius_ctx)); 252 253 // ------------------------------------------------------ 254 // SET UP Blasius 255 // ------------------------------------------------------ 256 problem->ics.qfunction = ICsBlasius; 257 problem->ics.qfunction_loc = ICsBlasius_loc; 258 259 CeedScalar U_inf = 40; // m/s 260 CeedScalar T_inf = 288.; // K 261 CeedScalar T_wall = 288.; // K 262 CeedScalar delta0 = 4.2e-3; // m 263 CeedScalar P_inf = 1.01e5; // Pa 264 PetscInt N = 20; // Number of Chebyshev terms 265 PetscBool weakT = PETSC_FALSE; // weak density or temperature 266 PetscReal mesh_refine_height = 5.9e-4; // m 267 PetscReal mesh_growth = 1.08; // [-] 268 PetscInt mesh_Ndelta = 45; // [-] 269 PetscReal mesh_top_angle = 5; // degrees 270 char mesh_ynodes_path[PETSC_MAX_PATH_LEN] = ""; 271 PetscBool P0_set; 272 273 PetscOptionsBegin(comm, NULL, "Options for BLASIUS problem", NULL); 274 PetscCall(PetscOptionsBool("-weakT", "Change from rho weak to T weak at inflow", NULL, weakT, &weakT, NULL)); 275 PetscCall(PetscOptionsScalar("-velocity_infinity", "Velocity at boundary layer edge", NULL, U_inf, &U_inf, NULL)); 276 PetscCall(PetscOptionsScalar("-temperature_infinity", "Temperature at boundary layer edge", NULL, T_inf, &T_inf, NULL)); 277 PetscCall(PetscOptionsHasName(NULL, NULL, "-P0", &P0_set)); // For maintaining behavior of -P0 flag (which is deprecated) 278 PetscCall( 279 PetscOptionsDeprecated("-P0", "-pressure_infinity", "libCEED 0.12.0", 280 "Use -pressure_infinity to set pressure at boundary layer edge and -idl_pressure to set the IDL reference pressure")); 281 PetscCall(PetscOptionsScalar("-pressure_infinity", "Pressure at boundary layer edge", NULL, P_inf, &P_inf, NULL)); 282 PetscCall(PetscOptionsScalar("-temperature_wall", "Temperature at wall", NULL, T_wall, &T_wall, NULL)); 283 PetscCall(PetscOptionsScalar("-delta0", "Boundary layer height at inflow", NULL, delta0, &delta0, NULL)); 284 PetscCall(PetscOptionsInt("-n_chebyshev", "Number of Chebyshev terms", NULL, N, &N, NULL)); 285 PetscCheck(3 <= N && N <= BLASIUS_MAX_N_CHEBYSHEV, comm, PETSC_ERR_ARG_OUTOFRANGE, "-n_chebyshev %" PetscInt_FMT " must be in range [3, %d]", N, 286 BLASIUS_MAX_N_CHEBYSHEV); 287 if (user->app_ctx->mesh_transform_type == MESH_TRANSFORM_PLATEMESH) { 288 PetscCall(PetscOptionsBoundedInt("-platemesh_Ndelta", "Velocity at boundary layer edge", NULL, mesh_Ndelta, &mesh_Ndelta, NULL, 1)); 289 PetscCall(PetscOptionsScalar("-platemesh_refine_height", "Height of boundary layer mesh refinement", NULL, mesh_refine_height, 290 &mesh_refine_height, NULL)); 291 PetscCall(PetscOptionsScalar("-platemesh_growth", "Geometric growth rate of boundary layer mesh", NULL, mesh_growth, &mesh_growth, NULL)); 292 PetscCall( 293 PetscOptionsScalar("-platemesh_top_angle", "Geometric top_angle rate of boundary layer mesh", NULL, mesh_top_angle, &mesh_top_angle, NULL)); 294 PetscCall(PetscOptionsString("-platemesh_y_node_locs_path", 295 "Path to file with y node locations. " 296 "If empty, will use the algorithmic mesh warping.", 297 NULL, mesh_ynodes_path, mesh_ynodes_path, sizeof(mesh_ynodes_path), NULL)); 298 } 299 PetscCall(PetscOptionsBool("-stg_use", "Use STG inflow boundary condition", NULL, use_stg, &use_stg, NULL)); 300 PetscOptionsEnd(); 301 302 PetscScalar meter = user->units->meter; 303 PetscScalar second = user->units->second; 304 PetscScalar Kelvin = user->units->Kelvin; 305 PetscScalar Pascal = user->units->Pascal; 306 307 T_inf *= Kelvin; 308 T_wall *= Kelvin; 309 P_inf *= Pascal; 310 U_inf *= meter / second; 311 delta0 *= meter; 312 313 if (user->app_ctx->mesh_transform_type == MESH_TRANSFORM_PLATEMESH) { 314 PetscReal *mesh_ynodes = NULL; 315 PetscInt mesh_nynodes = 0; 316 if (strcmp(mesh_ynodes_path, "")) PetscCall(GetYNodeLocs(comm, mesh_ynodes_path, &mesh_ynodes, &mesh_nynodes)); 317 PetscCall(ModifyMesh(comm, dm, problem->dim, mesh_growth, mesh_Ndelta, mesh_refine_height, mesh_top_angle, &mesh_ynodes, &mesh_nynodes)); 318 PetscCall(PetscFree(mesh_ynodes)); 319 } 320 321 // Some properties depend on parameters from NewtonianIdealGas 322 PetscCallCeed(ceed, CeedQFunctionContextGetData(problem->apply_vol_rhs.qfunction_context, CEED_MEM_HOST, &newtonian_ig_ctx)); 323 324 StatePrimitive Y_inf = { 325 .pressure = P_inf, .velocity = {U_inf, 0, 0}, 326 .temperature = T_inf 327 }; 328 State S_infty = StateFromPrimitive(newtonian_ig_ctx, Y_inf); 329 330 blasius_ctx->weakT = weakT; 331 blasius_ctx->T_wall = T_wall; 332 blasius_ctx->delta0 = delta0; 333 blasius_ctx->S_infty = S_infty; 334 blasius_ctx->n_cheb = N; 335 blasius_ctx->implicit = user->phys->implicit; 336 if (P0_set) newtonian_ig_ctx->idl_pressure = P_inf; // For maintaining behavior of -P0 flag (which is deprecated) 337 blasius_ctx->newtonian_ctx = *newtonian_ig_ctx; 338 339 { 340 PetscReal domain_min[3], domain_max[3]; 341 PetscCall(DMGetBoundingBox(dm, domain_min, domain_max)); 342 blasius_ctx->x_inflow = domain_min[0]; 343 blasius_ctx->eta_max = 5 * domain_max[1] / blasius_ctx->delta0; 344 } 345 PetscBool diff_filter_mms = PETSC_FALSE; 346 PetscCall(PetscOptionsGetBool(NULL, NULL, "-diff_filter_mms", &diff_filter_mms, NULL)); 347 if (!use_stg && !diff_filter_mms) PetscCall(ComputeChebyshevCoefficients(blasius_ctx)); 348 349 PetscCallCeed(ceed, CeedQFunctionContextRestoreData(problem->apply_vol_rhs.qfunction_context, &newtonian_ig_ctx)); 350 351 PetscCallCeed(ceed, CeedQFunctionContextCreate(user->ceed, &blasius_context)); 352 PetscCallCeed(ceed, CeedQFunctionContextSetData(blasius_context, CEED_MEM_HOST, CEED_USE_POINTER, sizeof(*blasius_ctx), blasius_ctx)); 353 PetscCallCeed(ceed, CeedQFunctionContextSetDataDestroy(blasius_context, CEED_MEM_HOST, FreeContextPetsc)); 354 355 PetscCallCeed(ceed, CeedQFunctionContextDestroy(&problem->ics.qfunction_context)); 356 problem->ics.qfunction_context = blasius_context; 357 if (use_stg) { 358 PetscCall(SetupStg(comm, dm, problem, user, weakT, S_infty.Y.temperature, S_infty.Y.pressure)); 359 } else if (diff_filter_mms) { 360 PetscCall(DifferentialFilterMmsICSetup(problem)); 361 } else { 362 PetscCheck((user->phys->state_var == STATEVAR_CONSERVATIVE) || (user->app_ctx->test_type == TESTTYPE_DIFF_FILTER), user->comm, 363 PETSC_ERR_ARG_INCOMP, "Can only use conservative variables with Blasius and weak inflow"); 364 problem->apply_inflow.qfunction = Blasius_Inflow; 365 problem->apply_inflow.qfunction_loc = Blasius_Inflow_loc; 366 problem->apply_inflow_jacobian.qfunction = Blasius_Inflow_Jacobian; 367 problem->apply_inflow_jacobian.qfunction_loc = Blasius_Inflow_Jacobian_loc; 368 PetscCallCeed(ceed, CeedQFunctionContextReferenceCopy(blasius_context, &problem->apply_inflow.qfunction_context)); 369 PetscCallCeed(ceed, CeedQFunctionContextReferenceCopy(blasius_context, &problem->apply_inflow_jacobian.qfunction_context)); 370 } 371 PetscFunctionReturn(PETSC_SUCCESS); 372 } 373