xref: /libCEED/examples/fluids/qfunctions/newtonian_state.h (revision a2d72b6f1ed489cbeb0eb5f72cf8bf977e7ff50a)
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 /// Structs and helper functions regarding the state of a newtonian simulation
10 #pragma once
11 
12 #include <ceed.h>
13 #include <math.h>
14 
15 #include "newtonian_types.h"
16 #include "utils.h"
17 
18 typedef struct {
19   CeedScalar density;
20   CeedScalar momentum[3];
21   CeedScalar E_total;
22 } StateConservative;
23 
24 typedef struct {
25   StateConservative U;
26   StatePrimitive    Y;
27   StateEntropy      V;
28 } State;
29 
30 CEED_QFUNCTION_HELPER void UnpackState_U(StateConservative s, CeedScalar U[5]) {
31   U[0] = s.density;
32   for (int i = 0; i < 3; i++) U[i + 1] = s.momentum[i];
33   U[4] = s.E_total;
34 }
35 
36 CEED_QFUNCTION_HELPER void UnpackState_Y(StatePrimitive s, CeedScalar Y[5]) {
37   Y[0] = s.pressure;
38   for (int i = 0; i < 3; i++) Y[i + 1] = s.velocity[i];
39   Y[4] = s.temperature;
40 }
41 
42 CEED_QFUNCTION_HELPER void UnpackState_V(StateEntropy s, CeedScalar V[5]) {
43   V[0] = s.S_density;
44   for (int i = 0; i < 3; i++) V[i + 1] = s.S_momentum[i];
45   V[4] = s.S_energy;
46 }
47 
48 CEED_QFUNCTION_HELPER CeedScalar HeatCapacityRatio(NewtonianIdealGasContext gas) { return gas->cp / gas->cv; }
49 
50 CEED_QFUNCTION_HELPER CeedScalar GasConstant(NewtonianIdealGasContext gas) { return gas->cp - gas->cv; }
51 
52 CEED_QFUNCTION_HELPER CeedScalar Prandtl(NewtonianIdealGasContext gas) { return gas->cp * gas->mu / gas->k; }
53 
54 CEED_QFUNCTION_HELPER CeedScalar SoundSpeed(NewtonianIdealGasContext gas, CeedScalar T) { return sqrt(gas->cp * (HeatCapacityRatio(gas) - 1.) * T); }
55 
56 CEED_QFUNCTION_HELPER CeedScalar Mach(NewtonianIdealGasContext gas, CeedScalar T, CeedScalar u) { return u / SoundSpeed(gas, T); }
57 
58 CEED_QFUNCTION_HELPER CeedScalar TotalSpecificEnthalpy(NewtonianIdealGasContext gas, const State s) {
59   // Ignoring potential energy
60   CeedScalar e_internal = gas->cv * s.Y.temperature;
61   CeedScalar e_kinetic  = 0.5 * Dot3(s.Y.velocity, s.Y.velocity);
62   return e_internal + e_kinetic + s.Y.pressure / s.U.density;
63 }
64 
65 CEED_QFUNCTION_HELPER CeedScalar TotalSpecificEnthalpy_fwd(NewtonianIdealGasContext gas, const State s, const State ds) {
66   // Ignoring potential energy
67   CeedScalar de_kinetic  = Dot3(ds.Y.velocity, s.Y.velocity);
68   CeedScalar de_internal = gas->cv * ds.Y.temperature;
69   return de_internal + de_kinetic + ds.Y.pressure / s.U.density - s.Y.pressure / Square(s.U.density) * ds.U.density;
70 }
71 
72 CEED_QFUNCTION_HELPER StatePrimitive StatePrimitiveFromConservative(NewtonianIdealGasContext gas, StateConservative U) {
73   StatePrimitive Y;
74   for (CeedInt i = 0; i < 3; i++) Y.velocity[i] = U.momentum[i] / U.density;
75   CeedScalar e_kinetic  = .5 * Dot3(Y.velocity, Y.velocity);
76   CeedScalar e_total    = U.E_total / U.density;
77   CeedScalar e_internal = e_total - e_kinetic;
78   Y.temperature         = e_internal / gas->cv;
79   Y.pressure            = (HeatCapacityRatio(gas) - 1) * U.density * e_internal;
80   return Y;
81 }
82 
83 CEED_QFUNCTION_HELPER StatePrimitive StatePrimitiveFromConservative_fwd(NewtonianIdealGasContext gas, State s, StateConservative dU) {
84   StatePrimitive dY;
85   for (CeedInt i = 0; i < 3; i++) {
86     dY.velocity[i] = (dU.momentum[i] - s.Y.velocity[i] * dU.density) / s.U.density;
87   }
88   CeedScalar e_kinetic   = .5 * Dot3(s.Y.velocity, s.Y.velocity);
89   CeedScalar de_kinetic  = Dot3(dY.velocity, s.Y.velocity);
90   CeedScalar e_total     = s.U.E_total / s.U.density;
91   CeedScalar de_total    = (dU.E_total - e_total * dU.density) / s.U.density;
92   CeedScalar e_internal  = e_total - e_kinetic;
93   CeedScalar de_internal = de_total - de_kinetic;
94   dY.temperature         = de_internal / gas->cv;
95   dY.pressure            = (HeatCapacityRatio(gas) - 1) * (dU.density * e_internal + s.U.density * de_internal);
96   return dY;
97 }
98 
99 CEED_QFUNCTION_HELPER StateConservative StateConservativeFromPrimitive(NewtonianIdealGasContext gas, StatePrimitive Y) {
100   StateConservative U;
101   U.density = Y.pressure / (GasConstant(gas) * Y.temperature);
102   for (int i = 0; i < 3; i++) U.momentum[i] = U.density * Y.velocity[i];
103   CeedScalar e_internal = gas->cv * Y.temperature;
104   CeedScalar e_kinetic  = .5 * Dot3(Y.velocity, Y.velocity);
105   CeedScalar e_total    = e_internal + e_kinetic;
106   U.E_total             = U.density * e_total;
107   return U;
108 }
109 
110 CEED_QFUNCTION_HELPER StateConservative StateConservativeFromPrimitive_fwd(NewtonianIdealGasContext gas, State s, StatePrimitive dY) {
111   StateConservative dU;
112   dU.density = (dY.pressure * s.Y.temperature - s.Y.pressure * dY.temperature) / (GasConstant(gas) * s.Y.temperature * s.Y.temperature);
113   for (int i = 0; i < 3; i++) {
114     dU.momentum[i] = dU.density * s.Y.velocity[i] + s.U.density * dY.velocity[i];
115   }
116   CeedScalar e_kinetic   = .5 * Dot3(s.Y.velocity, s.Y.velocity);
117   CeedScalar de_kinetic  = Dot3(dY.velocity, s.Y.velocity);
118   CeedScalar e_internal  = gas->cv * s.Y.temperature;
119   CeedScalar de_internal = gas->cv * dY.temperature;
120   CeedScalar e_total     = e_internal + e_kinetic;
121   CeedScalar de_total    = de_internal + de_kinetic;
122   dU.E_total             = dU.density * e_total + s.U.density * de_total;
123   return dU;
124 }
125 
126 CEED_QFUNCTION_HELPER StateEntropy StateEntropyFromConservative(NewtonianIdealGasContext gas, StateConservative U) {
127   StateEntropy     V;
128   const CeedScalar gamma      = HeatCapacityRatio(gas);
129   const CeedScalar e_kinetic  = .5 * Dot3(U.momentum, U.momentum) / U.density;
130   const CeedScalar e_internal = U.E_total - e_kinetic;
131   const CeedScalar p          = (gamma - 1) * e_internal;
132   const CeedScalar entropy    = log(p) - gamma * log(U.density);
133 
134   V.S_density = (gamma - entropy) / (gamma - 1) - e_kinetic / p;
135   for (int i = 0; i < 3; i++) V.S_momentum[i] = U.momentum[i] / p;
136   V.S_energy = -U.density / p;
137   return V;
138 }
139 
140 CEED_QFUNCTION_HELPER StateEntropy StateEntropyFromConservative_fwd(NewtonianIdealGasContext gas, State s, StateConservative dU) {
141   StateEntropy     dV;
142   const CeedScalar gamma       = HeatCapacityRatio(gas);
143   const CeedScalar e_kinetic   = .5 * Dot3(s.U.momentum, s.U.momentum) / s.U.density;
144   const CeedScalar de_kinetic  = (Dot3(s.U.momentum, dU.momentum) - e_kinetic * dU.density) / s.U.density;
145   const CeedScalar de_internal = dU.E_total - de_kinetic;
146   const CeedScalar p           = s.Y.pressure;
147   const CeedScalar dp          = (gamma - 1) * de_internal;
148 
149   CeedScalar dentropy = dp / p - gamma * dU.density / s.U.density;
150 
151   dV.S_density = -dentropy / (gamma - 1) - de_kinetic / p + dp * e_kinetic / Square(p);
152   for (CeedInt i = 0; i < 3; i++) {
153     dV.S_momentum[i] = (dU.momentum[i] - s.U.momentum[i] * dp / p) / p;
154   }
155   dV.S_energy = -(dU.density - s.U.density * dp / p) / p;
156   return dV;
157 }
158 
159 CEED_QFUNCTION_HELPER StateConservative StateConservativeFromEntropy(NewtonianIdealGasContext gas, StateEntropy V) {
160   StateConservative U;
161   CeedScalar        velocity[3];
162   for (int i = 0; i < 3; i++) velocity[i] = -V.S_momentum[i] / V.S_energy;
163   const CeedScalar gamma     = HeatCapacityRatio(gas);
164   const CeedScalar e_kinetic = 0.5 * Dot3(velocity, velocity);
165   const CeedScalar entropy   = gamma - (gamma - 1) * (V.S_density - e_kinetic * V.S_energy);
166   const CeedScalar log_rho   = -(entropy + log(-V.S_energy)) / (gamma - 1);
167   U.density                  = exp(log_rho);
168   for (int i = 0; i < 3; i++) U.momentum[i] = U.density * velocity[i];
169 
170   const CeedScalar e_internal = -gas->cv / (GasConstant(gas) * V.S_energy);
171   U.E_total                   = U.density * (e_internal + e_kinetic);
172   return U;
173 }
174 
175 CEED_QFUNCTION_HELPER StateConservative StateConservativeFromEntropy_fwd(NewtonianIdealGasContext gas, State s, StateEntropy dV) {
176   StateConservative dU;
177   CeedScalar        dvelocity[3];
178   for (int i = 0; i < 3; i++) dvelocity[i] = (-dV.S_momentum[i] - s.Y.velocity[i] * dV.S_energy) / s.V.S_energy;
179   const CeedScalar gamma      = HeatCapacityRatio(gas);
180   const CeedScalar e_kinetic  = 0.5 * Dot3(s.Y.velocity, s.Y.velocity);
181   const CeedScalar de_kinetic = Dot3(dvelocity, s.Y.velocity);
182   const CeedScalar entropy    = gamma - (gamma - 1) * (s.V.S_density - e_kinetic * s.V.S_energy);
183   const CeedScalar dentropy   = -(gamma - 1) * (dV.S_density - (de_kinetic * s.V.S_energy + e_kinetic * dV.S_energy));
184   const CeedScalar log_rho    = -(entropy + log(-s.V.S_energy)) / (gamma - 1);
185   const CeedScalar rho        = exp(log_rho);
186   dU.density                  = -rho / (gamma - 1) * (dentropy + dV.S_energy / s.V.S_energy);
187   for (int i = 0; i < 3; i++) dU.momentum[i] = dU.density * s.Y.velocity[i] + s.U.density * dvelocity[i];
188 
189   const CeedScalar e_internal  = -gas->cv / (GasConstant(gas) * s.V.S_energy);
190   const CeedScalar de_internal = gas->cv * dV.S_energy / (GasConstant(gas) * s.V.S_energy * s.V.S_energy);
191   const CeedScalar e_total     = e_internal + e_kinetic;
192   dU.E_total                   = dU.density * e_total + s.U.density * (de_internal + de_kinetic);
193   return dU;
194 }
195 
196 CEED_QFUNCTION_HELPER StateEntropy StateEntropyFromPrimitive(NewtonianIdealGasContext gas, StatePrimitive Y) {
197   StateEntropy     V;
198   const CeedScalar gamma     = HeatCapacityRatio(gas);
199   const CeedScalar rho       = Y.pressure / (GasConstant(gas) * Y.temperature);
200   const CeedScalar entropy   = log(Y.pressure) - gamma * log(rho);
201   const CeedScalar rho_div_p = rho / Y.pressure;
202   const CeedScalar e_kinetic = 0.5 * Dot3(Y.velocity, Y.velocity);
203 
204   V.S_density = (gamma - entropy) / (gamma - 1) - rho_div_p * e_kinetic;
205   for (int i = 0; i < 3; i++) V.S_momentum[i] = rho_div_p * Y.velocity[i];
206   V.S_energy = -rho_div_p;
207   return V;
208 }
209 
210 CEED_QFUNCTION_HELPER StateEntropy StateEntropyFromPrimitive_fwd(NewtonianIdealGasContext gas, State s, StatePrimitive dY) {
211   StateEntropy     dV;
212   const CeedScalar gamma = HeatCapacityRatio(gas);
213   CeedScalar       drho  = (dY.pressure * s.Y.temperature - s.Y.pressure * dY.temperature) / (GasConstant(gas) * s.Y.temperature * s.Y.temperature);
214 
215   const CeedScalar e_kinetic  = .5 * Dot3(s.Y.velocity, s.Y.velocity);
216   const CeedScalar de_kinetic = Dot3(dY.velocity, s.Y.velocity);
217   const CeedScalar rho_div_p  = s.U.density / s.Y.pressure;
218   const CeedScalar drho_div_p = (drho * s.Y.pressure - s.U.density * dY.pressure) / Square(s.Y.pressure);
219 
220   CeedScalar dentropy = dY.pressure / s.Y.pressure - gamma * drho / s.U.density;
221 
222   dV.S_density = -dentropy / (gamma - 1) - de_kinetic * rho_div_p - e_kinetic * drho_div_p;
223   for (CeedInt i = 0; i < 3; i++) dV.S_momentum[i] = rho_div_p * dY.velocity[i] + drho_div_p * s.Y.velocity[i];
224   dV.S_energy = -drho_div_p;
225   return dV;
226 }
227 
228 CEED_QFUNCTION_HELPER StatePrimitive StatePrimitiveFromEntropy(NewtonianIdealGasContext gas, StateEntropy V) {
229   StatePrimitive Y;
230   for (int i = 0; i < 3; i++) Y.velocity[i] = -V.S_momentum[i] / V.S_energy;
231   Y.temperature              = -1 / (GasConstant(gas) * V.S_energy);
232   const CeedScalar gamma     = HeatCapacityRatio(gas);
233   const CeedScalar e_kinetic = 0.5 * Dot3(Y.velocity, Y.velocity);
234   const CeedScalar entropy   = gamma - (gamma - 1) * (V.S_density - e_kinetic * V.S_energy);
235   const CeedScalar log_P     = -(entropy + gamma * log(-V.S_energy)) / (gamma - 1);
236   Y.pressure                 = exp(log_P);
237   return Y;
238 }
239 
240 CEED_QFUNCTION_HELPER StatePrimitive StatePrimitiveFromEntropy_fwd(NewtonianIdealGasContext gas, State s, StateEntropy dV) {
241   StatePrimitive dY;
242   for (int i = 0; i < 3; i++) dY.velocity[i] = -(dV.S_momentum[i] - s.V.S_momentum[i] * dV.S_energy / s.V.S_energy) / s.V.S_energy;
243   dY.temperature              = dV.S_energy / (GasConstant(gas) * s.V.S_energy * s.V.S_energy);
244   const CeedScalar gamma      = HeatCapacityRatio(gas);
245   const CeedScalar e_kinetic  = 0.5 * Dot3(s.Y.velocity, s.Y.velocity);
246   const CeedScalar de_kinetic = Dot3(dY.velocity, s.Y.velocity);
247   const CeedScalar dentropy   = (1 - gamma) * (dV.S_density - e_kinetic * dV.S_energy - de_kinetic * s.V.S_energy);
248   dY.pressure                 = s.Y.pressure * (-dentropy - gamma * dV.S_energy / s.V.S_energy) / (gamma - 1);
249   return dY;
250 }
251 
252 CEED_QFUNCTION_HELPER State StateFromPrimitive(NewtonianIdealGasContext gas, StatePrimitive Y) {
253   StateConservative U = StateConservativeFromPrimitive(gas, Y);
254   StateEntropy      V = StateEntropyFromPrimitive(gas, Y);
255   State             s;
256   s.U = U;
257   s.Y = Y;
258   s.V = V;
259   return s;
260 }
261 
262 CEED_QFUNCTION_HELPER State StateFromPrimitive_fwd(NewtonianIdealGasContext gas, State s, StatePrimitive dY) {
263   StateConservative dU = StateConservativeFromPrimitive_fwd(gas, s, dY);
264   StateEntropy      dV = StateEntropyFromPrimitive_fwd(gas, s, dY);
265   State             ds;
266   ds.U = dU;
267   ds.Y = dY;
268   ds.V = dV;
269   return ds;
270 }
271 
272 // linear combination of n states
273 CEED_QFUNCTION_HELPER StateConservative StateConservativeMult(CeedInt n, const CeedScalar a[], const StateConservative X[]) {
274   StateConservative R = {0};
275   for (CeedInt i = 0; i < n; i++) {
276     R.density += a[i] * X[i].density;
277     for (int j = 0; j < 3; j++) R.momentum[j] += a[i] * X[i].momentum[j];
278     R.E_total += a[i] * X[i].E_total;
279   }
280   return R;
281 }
282 
283 CEED_QFUNCTION_HELPER StateConservative StateConservativeAXPBYPCZ(CeedScalar a, StateConservative X, CeedScalar b, StateConservative Y, CeedScalar c,
284                                                                   StateConservative Z) {
285   StateConservative R;
286   R.density = a * X.density + b * Y.density + c * Z.density;
287   for (int i = 0; i < 3; i++) R.momentum[i] = a * X.momentum[i] + b * Y.momentum[i] + c * Z.momentum[i];
288   R.E_total = a * X.E_total + b * Y.E_total + c * Z.E_total;
289   return R;
290 }
291 
292 CEED_QFUNCTION_HELPER void StateToU(NewtonianIdealGasContext gas, const State input, CeedScalar U[5]) { UnpackState_U(input.U, U); }
293 
294 CEED_QFUNCTION_HELPER void StateToY(NewtonianIdealGasContext gas, const State input, CeedScalar Y[5]) { UnpackState_Y(input.Y, Y); }
295 
296 CEED_QFUNCTION_HELPER void StateToV(NewtonianIdealGasContext gas, const State input, CeedScalar V[5]) { UnpackState_V(input.V, V); }
297 
298 CEED_QFUNCTION_HELPER void StateToQ(NewtonianIdealGasContext gas, const State input, CeedScalar Q[5], StateVariable state_var) {
299   switch (state_var) {
300     case STATEVAR_CONSERVATIVE:
301       StateToU(gas, input, Q);
302       break;
303     case STATEVAR_PRIMITIVE:
304       StateToY(gas, input, Q);
305       break;
306     case STATEVAR_ENTROPY:
307       StateToV(gas, input, Q);
308       break;
309   }
310 }
311 
312 CEED_QFUNCTION_HELPER State StateFromU(NewtonianIdealGasContext gas, const CeedScalar U[5]) {
313   State s;
314   s.U.density     = U[0];
315   s.U.momentum[0] = U[1];
316   s.U.momentum[1] = U[2];
317   s.U.momentum[2] = U[3];
318   s.U.E_total     = U[4];
319   s.Y             = StatePrimitiveFromConservative(gas, s.U);
320   s.V             = StateEntropyFromConservative(gas, s.U);
321   return s;
322 }
323 
324 CEED_QFUNCTION_HELPER State StateFromU_fwd(NewtonianIdealGasContext gas, State s, const CeedScalar dU[5]) {
325   State ds;
326   ds.U.density     = dU[0];
327   ds.U.momentum[0] = dU[1];
328   ds.U.momentum[1] = dU[2];
329   ds.U.momentum[2] = dU[3];
330   ds.U.E_total     = dU[4];
331   ds.Y             = StatePrimitiveFromConservative_fwd(gas, s, ds.U);
332   ds.V             = StateEntropyFromConservative_fwd(gas, s, ds.U);
333   return ds;
334 }
335 
336 CEED_QFUNCTION_HELPER State StateFromY(NewtonianIdealGasContext gas, const CeedScalar Y[5]) {
337   State s;
338   s.Y.pressure    = Y[0];
339   s.Y.velocity[0] = Y[1];
340   s.Y.velocity[1] = Y[2];
341   s.Y.velocity[2] = Y[3];
342   s.Y.temperature = Y[4];
343   s.U             = StateConservativeFromPrimitive(gas, s.Y);
344   s.V             = StateEntropyFromPrimitive(gas, s.Y);
345   return s;
346 }
347 
348 CEED_QFUNCTION_HELPER State StateFromY_fwd(NewtonianIdealGasContext gas, State s, const CeedScalar dY[5]) {
349   State ds;
350   ds.Y.pressure    = dY[0];
351   ds.Y.velocity[0] = dY[1];
352   ds.Y.velocity[1] = dY[2];
353   ds.Y.velocity[2] = dY[3];
354   ds.Y.temperature = dY[4];
355   ds.U             = StateConservativeFromPrimitive_fwd(gas, s, ds.Y);
356   ds.V             = StateEntropyFromPrimitive_fwd(gas, s, ds.Y);
357   return ds;
358 }
359 
360 CEED_QFUNCTION_HELPER State StateFromV(NewtonianIdealGasContext gas, const CeedScalar V[5]) {
361   State s;
362   s.V.S_density     = V[0];
363   s.V.S_momentum[0] = V[1];
364   s.V.S_momentum[1] = V[2];
365   s.V.S_momentum[2] = V[3];
366   s.V.S_energy      = V[4];
367   s.U               = StateConservativeFromEntropy(gas, s.V);
368   s.Y               = StatePrimitiveFromEntropy(gas, s.V);
369   return s;
370 }
371 
372 CEED_QFUNCTION_HELPER State StateFromV_fwd(NewtonianIdealGasContext gas, State s, const CeedScalar dV[5]) {
373   State ds;
374   ds.V.S_density     = dV[0];
375   ds.V.S_momentum[0] = dV[1];
376   ds.V.S_momentum[1] = dV[2];
377   ds.V.S_momentum[2] = dV[3];
378   ds.V.S_energy      = dV[4];
379   ds.U               = StateConservativeFromEntropy_fwd(gas, s, ds.V);
380   ds.Y               = StatePrimitiveFromEntropy_fwd(gas, s, ds.V);
381   return ds;
382 }
383 
384 CEED_QFUNCTION_HELPER State StateFromQ(NewtonianIdealGasContext gas, const CeedScalar Q[5], StateVariable state_var) {
385   State s;
386   switch (state_var) {
387     case STATEVAR_CONSERVATIVE:
388       s = StateFromU(gas, Q);
389       break;
390     case STATEVAR_PRIMITIVE:
391       s = StateFromY(gas, Q);
392       break;
393     case STATEVAR_ENTROPY:
394       s = StateFromV(gas, Q);
395       break;
396   }
397   return s;
398 }
399 
400 CEED_QFUNCTION_HELPER State StateFromQ_fwd(NewtonianIdealGasContext gas, State s, const CeedScalar dQ[5], StateVariable state_var) {
401   State ds;
402   switch (state_var) {
403     case STATEVAR_CONSERVATIVE:
404       ds = StateFromU_fwd(gas, s, dQ);
405       break;
406     case STATEVAR_PRIMITIVE:
407       ds = StateFromY_fwd(gas, s, dQ);
408       break;
409     case STATEVAR_ENTROPY:
410       ds = StateFromV_fwd(gas, s, dQ);
411       break;
412   }
413   return ds;
414 }
415 
416 CEED_QFUNCTION_HELPER void FluxInviscid(NewtonianIdealGasContext gas, State s, StateConservative Flux[3]) {
417   for (CeedInt i = 0; i < 3; i++) {
418     Flux[i].density = s.U.momentum[i];
419     for (CeedInt j = 0; j < 3; j++) Flux[i].momentum[j] = s.U.momentum[i] * s.Y.velocity[j] + s.Y.pressure * (i == j);
420     Flux[i].E_total = (s.U.E_total + s.Y.pressure) * s.Y.velocity[i];
421   }
422 }
423 
424 CEED_QFUNCTION_HELPER void FluxInviscid_fwd(NewtonianIdealGasContext gas, State s, State ds, StateConservative dFlux[3]) {
425   for (CeedInt i = 0; i < 3; i++) {
426     dFlux[i].density = ds.U.momentum[i];
427     for (CeedInt j = 0; j < 3; j++) {
428       dFlux[i].momentum[j] = ds.U.momentum[i] * s.Y.velocity[j] + s.U.momentum[i] * ds.Y.velocity[j] + ds.Y.pressure * (i == j);
429     }
430     dFlux[i].E_total = (ds.U.E_total + ds.Y.pressure) * s.Y.velocity[i] + (s.U.E_total + s.Y.pressure) * ds.Y.velocity[i];
431   }
432 }
433 
434 CEED_QFUNCTION_HELPER StateConservative FluxInviscidDotNormal(NewtonianIdealGasContext gas, State s, const CeedScalar normal[3]) {
435   StateConservative Flux[3], Flux_dot_n = {0};
436   FluxInviscid(gas, s, Flux);
437   for (CeedInt i = 0; i < 3; i++) {
438     Flux_dot_n.density += Flux[i].density * normal[i];
439     for (CeedInt j = 0; j < 3; j++) Flux_dot_n.momentum[j] += Flux[i].momentum[j] * normal[i];
440     Flux_dot_n.E_total += Flux[i].E_total * normal[i];
441   }
442   return Flux_dot_n;
443 }
444 
445 CEED_QFUNCTION_HELPER StateConservative FluxInviscidDotNormal_fwd(NewtonianIdealGasContext gas, State s, State ds, const CeedScalar normal[3]) {
446   StateConservative dFlux[3], Flux_dot_n = {0};
447   FluxInviscid_fwd(gas, s, ds, dFlux);
448   for (CeedInt i = 0; i < 3; i++) {
449     Flux_dot_n.density += dFlux[i].density * normal[i];
450     for (CeedInt j = 0; j < 3; j++) Flux_dot_n.momentum[j] += dFlux[i].momentum[j] * normal[i];
451     Flux_dot_n.E_total += dFlux[i].E_total * normal[i];
452   }
453   return Flux_dot_n;
454 }
455 
456 CEED_QFUNCTION_HELPER void FluxInviscidStrong(NewtonianIdealGasContext gas, State s, State ds[3], CeedScalar strong_conv[5]) {
457   for (CeedInt i = 0; i < 5; i++) strong_conv[i] = 0;
458   for (CeedInt i = 0; i < 3; i++) {
459     StateConservative dF[3];
460     FluxInviscid_fwd(gas, s, ds[i], dF);
461     CeedScalar dF_i[5];
462     UnpackState_U(dF[i], dF_i);
463     for (CeedInt j = 0; j < 5; j++) strong_conv[j] += dF_i[j];
464   }
465 }
466 
467 CEED_QFUNCTION_HELPER void FluxTotal(const StateConservative F_inviscid[3], CeedScalar stress[3][3], CeedScalar Fe[3], CeedScalar Flux[5][3]) {
468   for (CeedInt j = 0; j < 3; j++) {
469     Flux[0][j] = F_inviscid[j].density;
470     for (CeedInt k = 0; k < 3; k++) Flux[k + 1][j] = F_inviscid[j].momentum[k] - stress[k][j];
471     Flux[4][j] = F_inviscid[j].E_total + Fe[j];
472   }
473 }
474 
475 CEED_QFUNCTION_HELPER void FluxTotal_Boundary(const StateConservative F_inviscid[3], const CeedScalar stress[3][3], const CeedScalar Fe[3],
476                                               const CeedScalar normal[3], CeedScalar Flux[5]) {
477   for (CeedInt j = 0; j < 5; j++) Flux[j] = 0.;
478   for (CeedInt j = 0; j < 3; j++) {
479     Flux[0] += F_inviscid[j].density * normal[j];
480     for (CeedInt k = 0; k < 3; k++) {
481       Flux[k + 1] += (F_inviscid[j].momentum[k] - stress[k][j]) * normal[j];
482     }
483     Flux[4] += (F_inviscid[j].E_total + Fe[j]) * normal[j];
484   }
485 }
486 
487 CEED_QFUNCTION_HELPER void FluxTotal_RiemannBoundary(const StateConservative F_inviscid_normal, const CeedScalar stress[3][3], const CeedScalar Fe[3],
488                                                      const CeedScalar normal[3], CeedScalar Flux[5]) {
489   Flux[0] = F_inviscid_normal.density;
490   for (CeedInt k = 0; k < 3; k++) Flux[k + 1] = F_inviscid_normal.momentum[k];
491   Flux[4] = F_inviscid_normal.E_total;
492   for (CeedInt j = 0; j < 3; j++) {
493     for (CeedInt k = 0; k < 3; k++) {
494       Flux[k + 1] -= stress[k][j] * normal[j];
495     }
496     Flux[4] += Fe[j] * normal[j];
497   }
498 }
499 
500 CEED_QFUNCTION_HELPER void VelocityGradient(const State grad_s[3], CeedScalar grad_velocity[3][3]) {
501   grad_velocity[0][0] = grad_s[0].Y.velocity[0];
502   grad_velocity[0][1] = grad_s[1].Y.velocity[0];
503   grad_velocity[0][2] = grad_s[2].Y.velocity[0];
504   grad_velocity[1][0] = grad_s[0].Y.velocity[1];
505   grad_velocity[1][1] = grad_s[1].Y.velocity[1];
506   grad_velocity[1][2] = grad_s[2].Y.velocity[1];
507   grad_velocity[2][0] = grad_s[0].Y.velocity[2];
508   grad_velocity[2][1] = grad_s[1].Y.velocity[2];
509   grad_velocity[2][2] = grad_s[2].Y.velocity[2];
510 }
511 
512 CEED_QFUNCTION_HELPER void KMStrainRate(const CeedScalar grad_velocity[3][3], CeedScalar strain_rate[6]) {
513   const CeedScalar weight = 1 / sqrt(2.);  // Really sqrt(2.) / 2
514   strain_rate[0]          = grad_velocity[0][0];
515   strain_rate[1]          = grad_velocity[1][1];
516   strain_rate[2]          = grad_velocity[2][2];
517   strain_rate[3]          = weight * (grad_velocity[1][2] + grad_velocity[2][1]);
518   strain_rate[4]          = weight * (grad_velocity[0][2] + grad_velocity[2][0]);
519   strain_rate[5]          = weight * (grad_velocity[0][1] + grad_velocity[1][0]);
520 }
521 
522 // Kelvin-Mandel notation
523 CEED_QFUNCTION_HELPER void KMStrainRate_State(const State grad_s[3], CeedScalar strain_rate[6]) {
524   CeedScalar grad_velocity[3][3];
525   VelocityGradient(grad_s, grad_velocity);
526   KMStrainRate(grad_velocity, strain_rate);
527 }
528 
529 //@brief Given velocity gradient du_i/dx_j, return 0.5*(du_i/dx_j - du_j/dx_i)
530 CEED_QFUNCTION_HELPER void RotationRate(const CeedScalar grad_velocity[3][3], CeedScalar rotation_rate[3][3]) {
531   rotation_rate[0][0] = 0;
532   rotation_rate[1][1] = 0;
533   rotation_rate[2][2] = 0;
534   rotation_rate[1][2] = 0.5 * (grad_velocity[1][2] - grad_velocity[2][1]);
535   rotation_rate[0][2] = 0.5 * (grad_velocity[0][2] - grad_velocity[2][0]);
536   rotation_rate[0][1] = 0.5 * (grad_velocity[0][1] - grad_velocity[1][0]);
537   rotation_rate[2][1] = -rotation_rate[1][2];
538   rotation_rate[2][0] = -rotation_rate[0][2];
539   rotation_rate[1][0] = -rotation_rate[0][1];
540 }
541 
542 CEED_QFUNCTION_HELPER void NewtonianStress(NewtonianIdealGasContext gas, const CeedScalar strain_rate[6], CeedScalar stress[6]) {
543   CeedScalar div_u = strain_rate[0] + strain_rate[1] + strain_rate[2];
544   for (CeedInt i = 0; i < 6; i++) {
545     stress[i] = gas->mu * (2 * strain_rate[i] + gas->lambda * div_u * (i < 3));
546   }
547 }
548 
549 CEED_QFUNCTION_HELPER void ViscousEnergyFlux(NewtonianIdealGasContext gas, StatePrimitive Y, const State grad_s[3], const CeedScalar stress[3][3],
550                                              CeedScalar Fe[3]) {
551   for (CeedInt i = 0; i < 3; i++) {
552     Fe[i] = -Y.velocity[0] * stress[0][i] - Y.velocity[1] * stress[1][i] - Y.velocity[2] * stress[2][i] - gas->k * grad_s[i].Y.temperature;
553   }
554 }
555 
556 CEED_QFUNCTION_HELPER void ViscousEnergyFlux_fwd(NewtonianIdealGasContext gas, StatePrimitive Y, StatePrimitive dY, const State grad_ds[3],
557                                                  const CeedScalar stress[3][3], const CeedScalar dstress[3][3], CeedScalar dFe[3]) {
558   for (CeedInt i = 0; i < 3; i++) {
559     dFe[i] = -Y.velocity[0] * dstress[0][i] - dY.velocity[0] * stress[0][i] - Y.velocity[1] * dstress[1][i] - dY.velocity[1] * stress[1][i] -
560              Y.velocity[2] * dstress[2][i] - dY.velocity[2] * stress[2][i] - gas->k * grad_ds[i].Y.temperature;
561   }
562 }
563 
564 CEED_QFUNCTION_HELPER void Vorticity(const State grad_s[3], CeedScalar vorticity[3]) {
565   CeedScalar grad_velocity[3][3];
566   VelocityGradient(grad_s, grad_velocity);
567   Curl3(grad_velocity, vorticity);
568 }
569 
570 CEED_QFUNCTION_HELPER void StatePhysicalGradientFromReference(CeedInt Q, CeedInt i, NewtonianIdealGasContext gas, State s, StateVariable state_var,
571                                                               const CeedScalar *grad_q, const CeedScalar dXdx[3][3], State grad_s[3]) {
572   for (CeedInt k = 0; k < 3; k++) {
573     CeedScalar dqi[5];
574     for (CeedInt j = 0; j < 5; j++) {
575       dqi[j] =
576           grad_q[(Q * 5) * 0 + Q * j + i] * dXdx[0][k] + grad_q[(Q * 5) * 1 + Q * j + i] * dXdx[1][k] + grad_q[(Q * 5) * 2 + Q * j + i] * dXdx[2][k];
577     }
578     grad_s[k] = StateFromQ_fwd(gas, s, dqi, state_var);
579   }
580 }
581 
582 CEED_QFUNCTION_HELPER void StatePhysicalGradientFromReference_Boundary(CeedInt Q, CeedInt i, NewtonianIdealGasContext gas, State s,
583                                                                        StateVariable state_var, const CeedScalar *grad_q, const CeedScalar dXdx[2][3],
584                                                                        State grad_s[3]) {
585   for (CeedInt k = 0; k < 3; k++) {
586     CeedScalar dqi[5];
587     for (CeedInt j = 0; j < 5; j++) {
588       dqi[j] = grad_q[(Q * 5) * 0 + Q * j + i] * dXdx[0][k] + grad_q[(Q * 5) * 1 + Q * j + i] * dXdx[1][k];
589     }
590     grad_s[k] = StateFromQ_fwd(gas, s, dqi, state_var);
591   }
592 }
593