xref: /honee/problems/stg_shur14.c (revision a6e8f989aaa6b733abaa05a7879c1bbdb090d48c)
1 // Copyright (c) 2017-2022, 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 /// Implementation of the Synthetic Turbulence Generation (STG) algorithm
10 /// presented in Shur et al. 2014
11 
12 #include <stdlib.h>
13 #include <math.h>
14 #include <petsc.h>
15 #include "../navierstokes.h"
16 #include "stg_shur14.h"
17 #include "../qfunctions/stg_shur14.h"
18 
19 #ifndef M_PI
20 #define M_PI    3.14159265358979323846
21 #endif
22 
23 STGShur14Context global_stg_ctx;
24 
25 /*
26  * @brief Perform Cholesky decomposition on array of symmetric 3x3 matrices
27  *
28  * This assumes the input matrices are in order [11,22,33,12,13,23]. This
29  * format is also used for the output.
30  *
31  * @param[in]  comm   MPI_Comm
32  * @param[in]  nprofs Number of matrices in Rij
33  * @param[in]  Rij    Array of the symmetric matrices [6,nprofs]
34  * @param[out] Cij    Array of the Cholesky Decomposition matrices, [6,nprofs]
35  */
36 PetscErrorCode CalcCholeskyDecomp(MPI_Comm comm, PetscInt nprofs,
37                                   const CeedScalar Rij[6][nprofs], CeedScalar Cij[6][nprofs]) {
38   PetscFunctionBeginUser;
39   for (PetscInt i=0; i<nprofs; i++) {
40     Cij[0][i] = sqrt(Rij[0][i]);
41     Cij[3][i] = Rij[3][i] / Cij[0][i];
42     Cij[1][i] = sqrt(Rij[1][i] - pow(Cij[3][i], 2) );
43     Cij[4][i] = Rij[4][i] / Cij[0][i];
44     Cij[5][i] = (Rij[5][i] - Cij[3][i]*Cij[4][i]) / Cij[1][i];
45     Cij[2][i] = sqrt(Rij[2][i] - pow(Cij[4][i], 2) - pow(Cij[5][i], 2));
46 
47     if (isnan(Cij[0][i]) || isnan(Cij[1][i]) || isnan(Cij[2][i]))
48       SETERRQ(comm, -1, "Cholesky decomposition failed at profile point %d. "
49               "Either STGInflow has non-SPD matrix or contains nan.", i+1);
50   }
51   PetscFunctionReturn(0);
52 }
53 
54 
55 /*
56  * @brief Open a PHASTA *.dat file, grabbing dimensions and file pointer
57  *
58  * This function opens the file specified by `path` using `PetscFOpen` and
59  * passes the file pointer in `fp`. It is not closed in this function, thus
60  * `fp` must be closed sometime after this function has been called (using
61  * `PetscFClose` for example).
62  *
63  * Assumes that the first line of the file has the number of rows and columns
64  * as the only two entries, separated by a single space
65  *
66  * @param[in] comm MPI_Comm for the program
67  * @param[in] path Path to the file
68  * @param[in] char_array_len Length of the character array that should contain each line
69  * @param[out] dims Dimensions of the file, taken from the first line of the file
70  * @param[out] fp File pointer to the opened file
71  */
72 static PetscErrorCode OpenPHASTADatFile(const MPI_Comm comm,
73                                         const char path[PETSC_MAX_PATH_LEN], const PetscInt char_array_len,
74                                         PetscInt dims[2], FILE **fp) {
75   PetscErrorCode ierr;
76   PetscInt ndims;
77   char line[char_array_len];
78   char **array;
79 
80   PetscFunctionBeginUser;
81   ierr = PetscFOpen(comm, path, "r", fp); CHKERRQ(ierr);
82   ierr = PetscSynchronizedFGets(comm, *fp, char_array_len, line); CHKERRQ(ierr);
83   ierr = PetscStrToArray(line, ' ', &ndims, &array); CHKERRQ(ierr);
84   if (ndims != 2) SETERRQ(comm, -1,
85                             "Found %d dimensions instead of 2 on the first line of %s",
86                             ndims, path);
87 
88   for (PetscInt i=0; i<ndims; i++)  dims[i] = atoi(array[i]);
89   ierr = PetscStrToArrayDestroy(ndims, array); CHKERRQ(ierr);
90   PetscFunctionReturn(0);
91 }
92 
93 /*
94  * @brief Get the number of rows for the PHASTA file at path
95  *
96  * Assumes that the first line of the file has the number of rows and columns
97  * as the only two entries, separated by a single space
98  *
99  * @param[in] comm MPI_Comm for the program
100  * @param[in] path Path to the file
101  * @param[out] nrows Number of rows
102  */
103 static PetscErrorCode GetNRows(const MPI_Comm comm,
104                                const char path[PETSC_MAX_PATH_LEN], PetscInt *nrows) {
105   PetscErrorCode ierr;
106   const PetscInt char_array_len = 512;
107   PetscInt dims[2];
108   FILE *fp;
109 
110   PetscFunctionBeginUser;
111   ierr = OpenPHASTADatFile(comm, path, char_array_len, dims, &fp); CHKERRQ(ierr);
112   *nrows = dims[0];
113   ierr = PetscFClose(comm, fp); CHKERRQ(ierr);
114   PetscFunctionReturn(0);
115 }
116 
117 /*
118  * @brief Read the STGInflow file and load the contents into stg_ctx
119  *
120  * Assumes that the first line of the file has the number of rows and columns
121  * as the only two entries, separated by a single space.
122  * Assumes there are 14 columns in the file
123  *
124  * Function calculates the Cholesky decomposition from the Reynolds stress
125  * profile found in the file
126  *
127  * @param[in] comm MPI_Comm for the program
128  * @param[in] path Path to the STGInflow.dat file
129  * @param[inout] stg_ctx STGShur14Context where the data will be loaded into
130  */
131 static PetscErrorCode ReadSTGInflow(const MPI_Comm comm,
132                                     const char path[PETSC_MAX_PATH_LEN], STGShur14Context stg_ctx) {
133   PetscErrorCode ierr;
134   PetscInt ndims, dims[2];
135   FILE *fp;
136   const PetscInt char_array_len=512;
137   char line[char_array_len];
138   char **array;
139 
140   PetscFunctionBeginUser;
141 
142   ierr = OpenPHASTADatFile(comm, path, char_array_len, dims, &fp); CHKERRQ(ierr);
143 
144   CeedScalar rij[6][stg_ctx->nprofs];
145   CeedScalar *prof_dw = &stg_ctx->data[stg_ctx->offsets.prof_dw];
146   CeedScalar *eps = &stg_ctx->data[stg_ctx->offsets.eps];
147   CeedScalar *lt = &stg_ctx->data[stg_ctx->offsets.lt];
148   CeedScalar (*ubar)[stg_ctx->nprofs] = (CeedScalar (*)[stg_ctx->nprofs])
149                                         &stg_ctx->data[stg_ctx->offsets.ubar];
150 
151   for (PetscInt i=0; i<stg_ctx->nprofs; i++) {
152     ierr = PetscSynchronizedFGets(comm, fp, char_array_len, line); CHKERRQ(ierr);
153     ierr = PetscStrToArray(line, ' ', &ndims, &array); CHKERRQ(ierr);
154     if (ndims < dims[1]) SETERRQ(comm, -1,
155                                    "Line %d of %s does not contain enough columns (%d instead of %d)", i,
156                                    path, ndims, dims[1]);
157 
158     prof_dw[i] = (CeedScalar) atof(array[0]);
159     ubar[0][i] = (CeedScalar) atof(array[1]);
160     ubar[1][i] = (CeedScalar) atof(array[2]);
161     ubar[2][i] = (CeedScalar) atof(array[3]);
162     rij[0][i]  = (CeedScalar) atof(array[4]);
163     rij[1][i]  = (CeedScalar) atof(array[5]);
164     rij[2][i]  = (CeedScalar) atof(array[6]);
165     rij[3][i]  = (CeedScalar) atof(array[7]);
166     rij[4][i]  = (CeedScalar) atof(array[8]);
167     rij[5][i]  = (CeedScalar) atof(array[9]);
168     lt[i]      = (CeedScalar) atof(array[12]);
169     eps[i]     = (CeedScalar) atof(array[13]);
170 
171     if (prof_dw[i] < 0) SETERRQ(comm, -1,
172                                   "Distance to wall in %s cannot be negative", path);
173     if (lt[i] < 0) SETERRQ(comm, -1,
174                              "Turbulent length scale in %s cannot be negative", path);
175     if (eps[i] < 0) SETERRQ(comm, -1,
176                               "Turbulent dissipation in %s cannot be negative", path);
177 
178   }
179   CeedScalar (*cij)[stg_ctx->nprofs]  = (CeedScalar (*)[stg_ctx->nprofs])
180                                         &stg_ctx->data[stg_ctx->offsets.cij];
181   ierr = CalcCholeskyDecomp(comm, stg_ctx->nprofs, rij, cij); CHKERRQ(ierr);
182   ierr = PetscFClose(comm, fp); CHKERRQ(ierr);
183   PetscFunctionReturn(0);
184 }
185 
186 /*
187  * @brief Read the STGRand file and load the contents into stg_ctx
188  *
189  * Assumes that the first line of the file has the number of rows and columns
190  * as the only two entries, separated by a single space.
191  * Assumes there are 7 columns in the file
192  *
193  * @param[in]    comm    MPI_Comm for the program
194  * @param[in]    path    Path to the STGRand.dat file
195  * @param[inout] stg_ctx STGShur14Context where the data will be loaded into
196  */
197 static PetscErrorCode ReadSTGRand(const MPI_Comm comm,
198                                   const char path[PETSC_MAX_PATH_LEN],
199                                   STGShur14Context stg_ctx) {
200   PetscErrorCode ierr;
201   PetscInt ndims, dims[2];
202   FILE *fp;
203   const PetscInt char_array_len = 512;
204   char line[char_array_len];
205   char **array;
206 
207   PetscFunctionBeginUser;
208   ierr = OpenPHASTADatFile(comm, path, char_array_len, dims, &fp); CHKERRQ(ierr);
209 
210   CeedScalar *phi = &stg_ctx->data[stg_ctx->offsets.phi];
211   CeedScalar (*d)[stg_ctx->nmodes]     = (CeedScalar (*)[stg_ctx->nmodes])
212                                          &stg_ctx->data[stg_ctx->offsets.d];
213   CeedScalar (*sigma)[stg_ctx->nmodes] = (CeedScalar (*)[stg_ctx->nmodes])
214                                          &stg_ctx->data[stg_ctx->offsets.sigma];
215 
216   for (PetscInt i=0; i<stg_ctx->nmodes; i++) {
217     ierr = PetscSynchronizedFGets(comm, fp, char_array_len, line); CHKERRQ(ierr);
218     ierr = PetscStrToArray(line, ' ', &ndims, &array); CHKERRQ(ierr);
219     if (ndims < dims[1]) SETERRQ(comm, -1,
220                                    "Line %d of %s does not contain enough columns (%d instead of %d)", i,
221                                    path, ndims, dims[1]);
222 
223     d[0][i]     = (CeedScalar) atof(array[0]);
224     d[1][i]     = (CeedScalar) atof(array[1]);
225     d[2][i]     = (CeedScalar) atof(array[2]);
226     phi[i]      = (CeedScalar) atof(array[3]);
227     sigma[0][i] = (CeedScalar) atof(array[4]);
228     sigma[1][i] = (CeedScalar) atof(array[5]);
229     sigma[2][i] = (CeedScalar) atof(array[6]);
230   }
231   ierr = PetscFClose(comm, fp); CHKERRQ(ierr);
232   PetscFunctionReturn(0);
233 }
234 
235 /*
236  * @brief Read STG data from input paths and put in STGShur14Context
237  *
238  * Reads data from input paths and puts them into a STGShur14Context object.
239  * Data stored initially in `*pstg_ctx` will be copied over to the new
240  * STGShur14Context instance.
241  *
242  * @param[in]    comm            MPI_Comm for the program
243  * @param[in]    dm              DM for the program
244  * @param[in]    stg_inflow_path Path to STGInflow.dat file
245  * @param[in]    stg_rand_path   Path to STGRand.dat file
246  * @param[inout] pstg_ctx        Pointer to STGShur14Context where the data will be loaded into
247  */
248 PetscErrorCode GetSTGContextData(const MPI_Comm comm, const DM dm,
249                                  char stg_inflow_path[PETSC_MAX_PATH_LEN],
250                                  char stg_rand_path[PETSC_MAX_PATH_LEN],
251                                  STGShur14Context *pstg_ctx,
252                                  const CeedScalar ynodes[]) {
253   PetscErrorCode ierr;
254   PetscInt nmodes, nprofs;
255   STGShur14Context stg_ctx;
256   PetscFunctionBeginUser;
257 
258   // Get options
259   ierr = GetNRows(comm, stg_rand_path, &nmodes); CHKERRQ(ierr);
260   ierr = GetNRows(comm, stg_inflow_path, &nprofs); CHKERRQ(ierr);
261   if (nmodes > STG_NMODES_MAX)
262     SETERRQ(comm, 1, "Number of wavemodes in %s (%d) exceeds STG_NMODES_MAX (%d). "
263             "Change size of STG_NMODES_MAX and recompile", stg_rand_path, nmodes,
264             STG_NMODES_MAX);
265 
266   {
267     STGShur14Context s;
268     ierr = PetscCalloc1(1, &s); CHKERRQ(ierr);
269     *s = **pstg_ctx;
270     s->nmodes = nmodes;
271     s->nprofs = nprofs;
272     s->offsets.sigma   = 0;
273     s->offsets.d       = nmodes*3;
274     s->offsets.phi     = s->offsets.d       + nmodes*3;
275     s->offsets.kappa   = s->offsets.phi     + nmodes;
276     s->offsets.prof_dw = s->offsets.kappa   + nmodes;
277     s->offsets.ubar    = s->offsets.prof_dw + nprofs;
278     s->offsets.cij     = s->offsets.ubar    + nprofs*3;
279     s->offsets.eps     = s->offsets.cij     + nprofs*6;
280     s->offsets.lt      = s->offsets.eps     + nprofs;
281     s->offsets.ynodes  = s->offsets.lt      + nprofs;
282     PetscInt total_num_scalars = s->offsets.ynodes + s->nynodes;
283     s->total_bytes = sizeof(*stg_ctx) + total_num_scalars*sizeof(stg_ctx->data[0]);
284     ierr = PetscMalloc(s->total_bytes, &stg_ctx); CHKERRQ(ierr);
285     *stg_ctx = *s;
286     ierr = PetscFree(s); CHKERRQ(ierr);
287   }
288 
289   ierr = ReadSTGInflow(comm, stg_inflow_path, stg_ctx); CHKERRQ(ierr);
290   ierr = ReadSTGRand(comm, stg_rand_path, stg_ctx); CHKERRQ(ierr);
291 
292   if (stg_ctx->nynodes > 0) {
293     CeedScalar *ynodes_ctx = &stg_ctx->data[stg_ctx->offsets.ynodes];
294     for (PetscInt i=0; i<stg_ctx->nynodes; i++) ynodes_ctx[i] = ynodes[i];
295   }
296 
297   // -- Calculate kappa
298   {
299     CeedScalar *kappa = &stg_ctx->data[stg_ctx->offsets.kappa];
300     CeedScalar *prof_dw = &stg_ctx->data[stg_ctx->offsets.prof_dw];
301     CeedScalar *lt = &stg_ctx->data[stg_ctx->offsets.lt];
302     CeedScalar le, le_max=0;
303 
304     CeedPragmaSIMD
305     for (PetscInt i=0; i<stg_ctx->nprofs; i++) {
306       le = PetscMin(2*prof_dw[i], 3*lt[i]);
307       if (le_max < le) le_max = le;
308     }
309     CeedScalar kmin = M_PI/le_max;
310 
311     CeedPragmaSIMD
312     for (PetscInt i=0; i<stg_ctx->nmodes; i++) {
313       kappa[i] = kmin*pow(stg_ctx->alpha, i);
314     }
315   } //end calculate kappa
316 
317   ierr = PetscFree(*pstg_ctx); CHKERRQ(ierr);
318   *pstg_ctx = stg_ctx;
319   PetscFunctionReturn(0);
320 }
321 
322 PetscErrorCode SetupSTG(const MPI_Comm comm, const DM dm, ProblemData *problem,
323                         User user, const bool prescribe_T,
324                         const CeedScalar theta0, const CeedScalar P0,
325                         const CeedScalar ynodes[], const CeedInt nynodes) {
326   PetscErrorCode ierr;
327   char stg_inflow_path[PETSC_MAX_PATH_LEN] = "./STGInflow.dat";
328   char stg_rand_path[PETSC_MAX_PATH_LEN]   = "./STGRand.dat";
329   PetscBool  mean_only     = PETSC_FALSE,
330              use_stgstrong = PETSC_FALSE;
331   CeedScalar u0            = 0.0,
332              alpha         = 1.01;
333   CeedQFunctionContext stg_context;
334   NewtonianIdealGasContext newtonian_ig_ctx;
335   PetscFunctionBeginUser;
336 
337   // Get options
338   PetscOptionsBegin(comm, NULL, "STG Boundary Condition Options", NULL);
339   ierr = PetscOptionsString("-stg_inflow_path", "Path to STGInflow.dat", NULL,
340                             stg_inflow_path, stg_inflow_path,
341                             sizeof(stg_inflow_path), NULL); CHKERRQ(ierr);
342   ierr = PetscOptionsString("-stg_rand_path", "Path to STGInflow.dat", NULL,
343                             stg_rand_path,stg_rand_path,
344                             sizeof(stg_rand_path), NULL); CHKERRQ(ierr);
345   ierr = PetscOptionsReal("-stg_alpha", "Growth rate of the wavemodes", NULL,
346                           alpha, &alpha, NULL); CHKERRQ(ierr);
347   ierr = PetscOptionsReal("-stg_u0", "Advective velocity for the fluctuations",
348                           NULL, u0, &u0, NULL); CHKERRQ(ierr);
349   ierr = PetscOptionsBool("-stg_mean_only", "Only apply mean profile",
350                           NULL, mean_only, &mean_only, NULL); CHKERRQ(ierr);
351   ierr = PetscOptionsBool("-stg_strong", "Enforce STG inflow strongly",
352                           NULL, use_stgstrong, &use_stgstrong, NULL); CHKERRQ(ierr);
353   PetscOptionsEnd();
354 
355   ierr = PetscCalloc1(1, &global_stg_ctx); CHKERRQ(ierr);
356   global_stg_ctx->alpha         = alpha;
357   global_stg_ctx->u0            = u0;
358   global_stg_ctx->is_implicit   = user->phys->implicit;
359   global_stg_ctx->prescribe_T   = prescribe_T;
360   global_stg_ctx->mean_only     = mean_only;
361   global_stg_ctx->theta0        = theta0;
362   global_stg_ctx->P0            = P0;
363   global_stg_ctx->nynodes       = nynodes;
364 
365   {
366     // Calculate dx assuming constant spacing
367     PetscReal domain_min[3], domain_max[3], domain_size[3];
368     ierr = DMGetBoundingBox(dm, domain_min, domain_max); CHKERRQ(ierr);
369     for (PetscInt i=0; i<3; i++) domain_size[i] = domain_max[i] - domain_min[i];
370 
371     PetscInt nmax = 3, faces[3];
372     ierr = PetscOptionsGetIntArray(NULL, NULL, "-dm_plex_box_faces", faces, &nmax,
373                                    NULL); CHKERRQ(ierr);
374     global_stg_ctx->dx = domain_size[0]/faces[0];
375     global_stg_ctx->dz = domain_size[2]/faces[2];
376   }
377 
378   CeedQFunctionContextGetData(problem->apply_vol_rhs.qfunction_context,
379                               CEED_MEM_HOST, &newtonian_ig_ctx);
380   global_stg_ctx->newtonian_ctx = *newtonian_ig_ctx;
381   CeedQFunctionContextRestoreData(problem->apply_vol_rhs.qfunction_context,
382                                   &newtonian_ig_ctx);
383 
384   ierr = GetSTGContextData(comm, dm, stg_inflow_path, stg_rand_path,
385                            &global_stg_ctx, ynodes); CHKERRQ(ierr);
386 
387   CeedQFunctionContextCreate(user->ceed, &stg_context);
388   CeedQFunctionContextSetData(stg_context, CEED_MEM_HOST,
389                               CEED_USE_POINTER, global_stg_ctx->total_bytes, global_stg_ctx);
390   CeedQFunctionContextSetDataDestroy(stg_context, CEED_MEM_HOST,
391                                      FreeContextPetsc);
392   CeedQFunctionContextRegisterDouble(stg_context, "solution time",
393                                      offsetof(struct STGShur14Context_, time), 1,
394                                      "Phyiscal time of the solution");
395 
396   CeedQFunctionContextDestroy(&problem->ics.qfunction_context);
397   problem->ics.qfunction         = ICsSTG;
398   problem->ics.qfunction_loc     = ICsSTG_loc;
399   problem->ics.qfunction_context = stg_context;
400 
401   if (use_stgstrong) {
402     // Use default boundary integral QF (BoundaryIntegral) in newtonian.h
403     problem->bc_from_ics           = PETSC_FALSE;
404   } else {
405     problem->apply_inflow.qfunction              = STGShur14_Inflow;
406     problem->apply_inflow.qfunction_loc          = STGShur14_Inflow_loc;
407     problem->apply_inflow_jacobian.qfunction     = STGShur14_Inflow_Jacobian;
408     problem->apply_inflow_jacobian.qfunction_loc = STGShur14_Inflow_Jacobian_loc;
409     CeedQFunctionContextReferenceCopy(stg_context,
410                                       &problem->apply_inflow.qfunction_context);
411     CeedQFunctionContextReferenceCopy(stg_context,
412                                       &problem->apply_inflow_jacobian.qfunction_context);
413     problem->bc_from_ics                    = PETSC_TRUE;
414   }
415 
416   PetscFunctionReturn(0);
417 }
418 
419 static inline PetscScalar FindDy(const PetscScalar ynodes[],
420                                  const PetscInt nynodes, const PetscScalar y) {
421 
422   const PetscScalar half_mindy = 0.5 * (ynodes[1] - ynodes[0]);
423   // ^^assuming min(dy) is first element off the wall
424   PetscInt idx = -1; // Index
425 
426   for (PetscInt i=0; i<nynodes; i++) {
427     if (y < ynodes[i] + half_mindy) {
428       idx = i; break;
429     }
430   }
431   if      (idx == 0)          return ynodes[1] - ynodes[0];
432   else if (idx == nynodes-1)  return ynodes[nynodes-2] - ynodes[nynodes-1];
433   else                        return 0.5 * (ynodes[idx+1] - ynodes[idx-1]);
434 }
435 
436 // Function passed to DMAddBoundary
437 PetscErrorCode StrongSTGbcFunc(PetscInt dim, PetscReal time,
438                                const PetscReal x[], PetscInt Nc, PetscScalar bcval[], void *ctx) {
439   PetscFunctionBeginUser;
440 
441   const STGShur14Context stg_ctx = (STGShur14Context) ctx;
442   PetscScalar qn[stg_ctx->nmodes], u[3], ubar[3], cij[6], eps, lt;
443   const bool mean_only      = stg_ctx->mean_only;
444   const PetscScalar dx      = stg_ctx->dx;
445   const PetscScalar dz      = stg_ctx->dz;
446   const PetscScalar mu      = stg_ctx->newtonian_ctx.mu;
447   const PetscScalar theta0  = stg_ctx->theta0;
448   const PetscScalar P0      = stg_ctx->P0;
449   const PetscScalar cv      = stg_ctx->newtonian_ctx.cv;
450   const PetscScalar cp      = stg_ctx->newtonian_ctx.cp;
451   const PetscScalar Rd      = cp - cv;
452 
453   const CeedScalar rho = P0 / (Rd * theta0);
454   InterpolateProfile(x[1], ubar, cij, &eps, &lt, stg_ctx);
455   if (!mean_only) {
456     const PetscInt    nynodes = stg_ctx->nynodes;
457     const PetscScalar *ynodes = &stg_ctx->data[stg_ctx->offsets.ynodes];
458     const PetscScalar h[3]    = {dx, FindDy(ynodes, nynodes, x[1]), dz};
459     CalcSpectrum(x[1], eps, lt, h, mu/rho, qn, stg_ctx);
460     STGShur14_Calc(x, time, ubar, cij, qn, u, stg_ctx);
461   } else {
462     for (CeedInt j=0; j<3; j++) u[j] = ubar[j];
463   }
464 
465   bcval[0] = rho;
466   bcval[1] = rho * u[0];
467   bcval[2] = rho * u[1];
468   bcval[3] = rho * u[2];
469   PetscFunctionReturn(0);
470 }
471 
472 PetscErrorCode SetupStrongSTG(DM dm, SimpleBC bc, ProblemData *problem) {
473   PetscErrorCode ierr;
474   DMLabel label;
475   const PetscInt comps[] = {0, 1, 2, 3};
476   const PetscInt num_comps = 4;
477   PetscFunctionBeginUser;
478 
479   ierr = DMGetLabel(dm, "Face Sets", &label); CHKERRQ(ierr);
480   // Set wall BCs
481   if (bc->num_inflow > 0) {
482     ierr = DMAddBoundary(dm, DM_BC_ESSENTIAL, "STG", label,
483                          bc->num_inflow, bc->inflows, 0, num_comps,
484                          comps, (void(*)(void))StrongSTGbcFunc,
485                          NULL, global_stg_ctx, NULL);  CHKERRQ(ierr);
486   }
487 
488   PetscFunctionReturn(0);
489 }
490