Alamo
Roe.H
Go to the documentation of this file.
1//
2// This implements the Riemann Roe solver.
3//
4// Notation and algorithm follow the presentation in Section 5.3.3
5// of *Computational Gasdynamics* by Culbert B. Laney (page 88)
6//
7// This solver uses an optional entropy fix
8// Option 1: chimeracfd method https://chimeracfd.com/programming/gryphon/fluxroe.html
9// Option 2: Eq. 4.3.67 in *Computational Fluid Dynamics for Engineers and Scientists* by Sreenivas Jayanti
10//
11
12#ifndef SOLVER_LOCAL_RIEMANN_ROE_H
13#define SOLVER_LOCAL_RIEMANN_ROE_H
14
15#include "IO/ParmParse.H"
16#include "Solver/Local/Riemann/Riemann.H"
17
18/// A bunch of solvers
19namespace Solver
20{
21/// Local solvers
22namespace Local
23{
24
25namespace Riemann
26{
27
28/// Roe Riemann Solver based on Gas Dynamics - Culbert B. Laney
29class Roe
30{
31public:
32
33
34 static constexpr const char* name = "roe";
35 Roe (IO::ParmParse &pp, std::string name)
36 {pp_queryclass(name,*this);}
37 Roe (IO::ParmParse &pp)
38 {pp_queryclass(*this);}
39 Roe ()
40 {
41 IO::ParmParse pp;
42 pp_queryclass(*this);
43 }
44
45 int verbose = 0;
46 int entropy_fix = 0;
47
48 static void Parse(Roe & value, IO::ParmParse & pp)
49 {
50 // enable to dump diagnostic data if the roe solver fails
51 pp.query_default("verbose", value.verbose, 1);
52 // apply entropy fix if tru
53 pp.query_default("entropy_fix", value.entropy_fix, false);
54
55 if (value.entropy_fix == 1)
56 Util::Warning(INFO,"The entropy fix is experimental and should be used with caution");
57 else if (value.entropy_fix == 2)
58 Util::Warning(INFO,"The entropy fix is experimental and should be used with caution. Has previously caused errors with FlowDrivenCavity regression test");
59 }
60
61 Flux Solve(State lo, State hi, Set::Scalar gamma, Set::Scalar p_ref, Set::Scalar small)
62 {
63 Set::Scalar rho_L = lo.rho , rho_R = hi.rho;
64 Set::Scalar Mn_L = lo.M_normal , Mn_R = hi.M_normal ;
65 Set::Scalar Mt_L = lo.M_tangent , Mt_R = hi.M_tangent ;
66 Set::Scalar E_L = lo.E , E_R = hi.E ;
67
68 // Ensure no negative densities
69 rho_L = std::max(0.0,rho_L);
70 rho_R = std::max(0.0,rho_R);
71
72 // STEP 1: Compute fluid primitives
73 Set::Scalar ke_L = 0.5 * (Mn_L * Mn_L /*+ Mt_L * Mt_L*/) / (rho_L+small); // KE per unit volume
74 Set::Scalar ue_L = E_L - ke_L; // IE per unit volume
75 Set::Scalar p_L = (gamma - 1.0) * ue_L + p_ref; // pressure
76 Set::Scalar h_TL = (ke_L + ue_L + p_L) / (rho_L+small); // specific stagnation enthalpy (per unit mass)
77
78 Set::Scalar ke_R = 0.5 * (Mn_R * Mn_R /*+ Mt_R * Mt_R*/) / (rho_R+small);
79 Set::Scalar ue_R = E_R - ke_R;
80 Set::Scalar p_R = (gamma - 1.0) * ue_R + p_ref;
81 Set::Scalar h_TR = (ke_R + ue_R + p_R) / (rho_R+small);
82
83 Set::Scalar u_L = Mn_L/(rho_L+small), u_R = Mn_R/(rho_R+small);
84 Set::Scalar v_L = Mt_L/(rho_L+small), v_R = Mt_R/(rho_R+small);
85
86 //
87 // STEP 2: Compute Roe-averaged quantities
88 //
89 Set::Scalar rho_RL = std::sqrt(rho_L * rho_R);
90 Set::Scalar u_RL = (std::sqrt(rho_L) * u_L + std::sqrt(rho_R) * u_R ) / (std::sqrt(rho_L) + std::sqrt(rho_R) + small);
91 Set::Scalar h_RL = (std::sqrt(rho_L) * h_TL + std::sqrt(rho_R) * h_TR) / (std::sqrt(rho_L) + std::sqrt(rho_R) + small);
92 Set::Scalar a_RL_sq = std::max(0.0,(gamma - 1.0) * (h_RL - 0.5 * u_RL * u_RL));
93
94 if (verbose && ((a_RL_sq<0) || (a_RL_sq!=a_RL_sq)))
95 {
96 Util::Message(INFO, "sound speed ", a_RL_sq);
97
98 Util::Message(INFO, "mixed rho ", lo.rho, " ", hi.rho);
99 Util::Message(INFO, "mixed Mn ", lo.M_normal, " ", hi.M_normal);
100 Util::Message(INFO, "mixed Mt ", lo.M_tangent, " ", hi.M_tangent);
101 Util::Message(INFO, "mixed E ", lo.E, " ", hi.E);
102
103 Util::Message(INFO, "fluid rho ", rho_L, " ", rho_R);
104 Util::Message(INFO, "fluid Mn ", Mn_L, " ", Mn_R);
105 Util::Message(INFO, "fluid Mt ", Mt_L, " ", Mt_R);
106 Util::Message(INFO, "fluid E ", E_L, " ", E_R);
107
108 Util::Message(INFO, "fluid rho ", rho_L, " ", rho_R);
109 Util::Message(INFO, "fluid u ", u_L, " ", u_R);
110 Util::Message(INFO, "fluid v ", v_L, " ", v_R);
111 Util::Message(INFO, "fluid p ", p_L, " ", p_R);
112 }
113 Util::AssertException(INFO,TEST(a_RL_sq==a_RL_sq)," a_RL_sq is nan/inf; (a_RL_sq=", a_RL_sq,")");
114 Util::AssertException(INFO,TEST(a_RL_sq>=0), " a_RL_sq is negative; (a_RL_sq=(",a_RL_sq,")");
115
116 Set::Scalar a_RL = std::sqrt(a_RL_sq) + small;
117
118 //
119 // STEP 3: Compute Roe-averaged wave speeds
120 //
121 Set::Scalar lambda1 = u_RL; // 5.53a
122 Set::Scalar lambda2 = u_RL + a_RL; // 5.53b
123 Set::Scalar lambda3 = u_RL - a_RL; // 5.53c
124
125 //
126 // STEP 4: Compute wave strengths
127 //
128 Set::Scalar deltarho= rho_R - rho_L;
129 Set::Scalar deltap = p_R - p_L;
130 Set::Scalar deltau = u_R - u_L;
131
132 Set::Scalar deltav1 = deltarho - deltap / (a_RL_sq + small); // 5.54a
133 Set::Scalar deltav2 = deltau + deltap / (rho_RL * a_RL + small); // 5.54b
134 Set::Scalar deltav3 = deltau - deltap / (rho_RL * a_RL + small); // 5.54c
135
136 //
137 // STEP 5: Compute the right eigenvectors
138 //
139 Set::Scalar r11 = 1.0;
140 Set::Scalar r12 = u_RL;
141 Set::Scalar r13 = 0.5*u_RL*u_RL;
142 Set::Scalar r21 = 0.5*rho_RL/a_RL;
143 Set::Scalar r22 = 0.5*rho_RL/a_RL * ( u_RL + a_RL );
144 Set::Scalar r23 = 0.5*rho_RL/a_RL * ( h_RL + a_RL*u_RL );
145 Set::Scalar r31 = -0.5*rho_RL/a_RL;
146 Set::Scalar r32 = -0.5*rho_RL/a_RL * ( u_RL - a_RL );
147 Set::Scalar r33 = -0.5*rho_RL/a_RL * ( h_RL - a_RL*u_RL );
148
149 //
150 // STEP 6: Compute solution - not needed since fluxes will be computed in STEP 7
151 //
152
153 //
154 // ROE ENTROPY FIX (Source cited in header comments)
155 //
156 if (entropy_fix == 1) { // chimeracfd
157 lambda1 = fabs(lambda1);
158 lambda2 = fabs(lambda2);
159 lambda3 = fabs(lambda3);
160 if ( lambda1 < deltau ) lambda1 = 0.5*(lambda1*lambda1 + deltau*deltau)/deltau;
161 if ( lambda2 < deltau ) lambda2 = 0.5*(lambda2*lambda2 + deltau*deltau)/deltau;
162 if ( lambda3 < deltau ) lambda3 = 0.5*(lambda3*lambda3 + deltau*deltau)/deltau;
163 }
164 else if (entropy_fix == 2) { // Jayanti
165 Set::Scalar a_L = std::sqrt(gamma * p_L / (rho_L + small)); // sound speed
166 Set::Scalar a_R = std::sqrt(gamma * p_R / (rho_R + small));
167 Set::Scalar lambda1_L = u_L; Set::Scalar lambda1_R = u_R; // eigenvalues
168 Set::Scalar lambda2_L = u_L + a_L; Set::Scalar lambda2_R = u_R + a_R;
169 Set::Scalar lambda3_L = u_L - a_L; Set::Scalar lambda3_R = u_R - a_R;
170 Set::Scalar fix1 = std::max(0.0, std::max(lambda1 - lambda1_L, lambda1_R - lambda1));
171 Set::Scalar fix2 = std::max(0.0, std::max(lambda2 - lambda2_L, lambda2_R - lambda2));
172 Set::Scalar fix3 = std::max(0.0, std::max(lambda3 - lambda3_L, lambda3_R - lambda3));
173 if ( lambda1 < fix1 ) lambda1 = fix1;
174 if ( lambda2 < fix2 ) lambda2 = fix2;
175 if ( lambda3 < fix3 ) lambda3 = fix3;
176 }
177
178 //
179 // STEP 7: Compute fluxes
180 //
181 Flux fl;
182
183 fl.mass = (0.5*(rho_L*u_L + rho_R*u_R) - 0.5*(
184 r11*fabs(lambda1)*deltav1 +
185 r21*fabs(lambda2)*deltav2 +
186 r31*fabs(lambda3)*deltav3)
187 );
188
189 if (fl.mass != fl.mass)
190 {
191 if (verbose)
192 {
193 Util::ParallelMessage(INFO,"hi ", hi);
194 Util::ParallelMessage(INFO,"lo ", lo);
195 Util::ParallelMessage(INFO,"rho_R ", rho_R);
196 Util::ParallelMessage(INFO,"rho_L ", rho_L);
197 Util::ParallelMessage(INFO,"rho_RL ", rho_RL);
198 Util::ParallelMessage(INFO,"u_R ", u_R);
199 Util::ParallelMessage(INFO,"u_L ", u_L);
200 Util::ParallelMessage(INFO,"u_RL ", u_RL);
201 Util::ParallelMessage(INFO,"a_RL ", a_RL);
202 Util::ParallelMessage(INFO,"lambda1 ", lambda1);
203 Util::ParallelMessage(INFO,"lambda2 ", lambda2);
204 Util::ParallelMessage(INFO,"lambda3 ", lambda3);
205 Util::ParallelMessage(INFO,"deltav1 ", deltav1);
206 Util::ParallelMessage(INFO,"deltav2 ", deltav2);
207 Util::ParallelMessage(INFO,"deltav3 ", deltav3);
208 }
209 Util::Exception(INFO);
210 }
211
212
213 fl.momentum_normal = ( 0.5*(rho_L*u_L*u_L + p_L + rho_R*u_R*u_R + p_R) - 0.5*(
214 r12*fabs(lambda1)*deltav1 +
215 r22*fabs(lambda2)*deltav2 +
216 r32*fabs(lambda3)*deltav3)
217 );
218
219
220 fl.energy = ( 0.5*(u_L*(ke_L + p_L + ue_L) + u_R*(ke_R + p_R + ue_R)) - 0.5*
221 (
222 r13*fabs(lambda1)*deltav1 +
223 r23*fabs(lambda2)*deltav2 +
224 r33*fabs(lambda3)*deltav3)
225 );
226
227 //
228 // (Update the tangential momentum flux)
229 //
230 fl.momentum_tangent = 0.5 * (rho_L * u_L * v_L + rho_R * u_R * v_R);
231
232 return fl;
233 }
234
235
236 static int Test()
237 {
238 Roe solver;
239
240
241 int failed = 0;
242
243 Set::Scalar gamma = 1.4;
244 Set::Scalar pref = 10.0;
245 Set::Scalar small = 1E-10;
246
247 // Test 1: Tangential Velocity Difference - No Normal Flux
248 try {
249 State left (1.0, 1.0, 0.0, 1.0);
250 State center(1.0, 1.0, 1.0, 1.0);
251 State right (1.0, 1.0, 2.0, 1.0);
252 Flux fluxlo = solver.Solve(center, right, gamma, pref, small);
253 Flux fluxhi = solver.Solve(left, center, gamma, pref, small);
254
255 if (fabs(fluxhi.mass - fluxlo.mass) > 1E-10
256 || fabs(fluxhi.momentum_normal - fluxlo.momentum_normal) > 1E-10
257 || fabs(fluxhi.energy - fluxlo.energy) > 1E-10) {
258 Util::Warning(INFO, "left: ",left);
259 Util::Warning(INFO, "center: ",center);
260 Util::Warning(INFO, "right: ",right);
261 Util::Warning(INFO, "Fluxlo: ",fluxlo);
262 Util::Warning(INFO, "Fluxhi: ",fluxhi);
263 Util::Exception(INFO, "Tangential velocity difference incorrectly affecting normal flux.");
264 }
265 Util::Test::SubMessage("Test 1: Tangential velocity should induce no normal flux",0);
266 } catch (const std::runtime_error& e)
267 {
268 failed++;
269 Util::Test::SubMessage("Test 1: Tangential velocity should induce no normal flux",1);
270 }
271
272 // Test 2: Pure Transverse Velocity Difference
273 try {
274 State left (1.0, 0.0, 0.0, 1.0);
275 State center(1.0, 0.0, 1.0, 1.0);
276 State right (1.0, 0.0, 2.0, 1.0);
277 Flux fluxlo = solver.Solve(left, center, gamma, pref, small);
278 Flux fluxhi = solver.Solve(center, right, gamma, pref, small);
279 if (fabs(fluxhi.mass - fluxlo.mass) > 1E-10
280 || fabs(fluxhi.momentum_normal - fluxlo.momentum_normal) > 1E-10
281 || fabs(fluxhi.energy - fluxlo.energy) > 1E-10) {
282 Util::Warning(INFO, "left: ",left);
283 Util::Warning(INFO, "center: ",center);
284 Util::Warning(INFO, "right: ",right);
285 Util::Warning(INFO, "Fluxhi: ",fluxhi);
286 Util::Warning(INFO, "Fluxlo: ",fluxlo);
287 Util::Exception(INFO, "Pure transverse velocity difference affecting normal flux.");
288 }
289 Util::Test::SubMessage("Test 2: Pure transverse velocity difference",0);
290 } catch (const std::runtime_error& e)
291 {
292 failed++;
293 Util::Test::SubMessage("Test 2: Pure transverse velocity difference",1);
294 }
295
296 // Test 3: Symmetry Test (no flux across identical states)
297 try {
298 State left(1.0, 0.0, 0.0, 1.0);
299 State center(1.0, 0.0, 0.0, 1.0);
300 State right(1.0, 0.0, 0.0, 1.0);
301 Flux fluxhi = solver.Solve(center, right, gamma, pref, small);
302 Flux fluxlo = solver.Solve(left, center, gamma, pref, small);
303 if (fabs(fluxhi.mass - fluxlo.mass) > 1E-10 // no change in mass flux
304 || fabs(fluxhi.momentum_normal - fluxlo.momentum_normal) > 1E-10 // no change in momentum flux
305 || fabs(fluxhi.momentum_tangent) > 1E-10 // zero tangent flux
306 || fabs(fluxlo.momentum_tangent) > 1E-10 // zero tangent flux
307 || fabs(fluxhi.energy-fluxlo.energy) > 1E-10 // no change in energy flux
308 ) {
309 Util::Warning(INFO, "left: ",left);
310 Util::Warning(INFO, "right: ",right);
311 Util::Warning(INFO, "Fluxhi: ",fluxhi);
312 Util::Warning(INFO, "Fluxlo: ",fluxlo);
313 Util::Exception(INFO, "Symmetric states should result in zero flux.");
314 }
315 Util::Test::SubMessage("Test 3: Constant states induces no flux difference",0);
316 } catch (const std::runtime_error& e)
317 {
318 failed++;
319 Util::Test::SubMessage("Test 3: Constant states induces no flux difference",1);
320 }
321
322 // Test 4: Uniform Flow Test (no flux across uniform flow)
323 try {
324 State left (1.0, 1.0, 0.5, 1.0);
325 State center(1.0, 1.0, 0.5, 1.0);
326 State right (1.0, 1.0, 0.5, 1.0);
327 Flux fluxhi = solver.Solve(center, right, gamma, pref, small);
328 Flux fluxlo = solver.Solve(left, center, gamma, pref, small);
329 if (fabs(fluxhi.mass - fluxlo.mass) > 1E-10 ||
330 fabs(fluxhi.momentum_normal - fluxlo.momentum_normal) > 1E-10 ||
331 fabs(fluxhi.energy - fluxlo.energy) > 1E-10) {
332 Util::Warning(INFO, "left: ",left);
333 Util::Warning(INFO, "center: ",center);
334 Util::Warning(INFO, "right: ",right);
335 Util::Warning(INFO, "Fluxlo: ",fluxlo);
336 Util::Warning(INFO, "Fluxhi: ",fluxhi);
337 Util::Exception(INFO, "Uniform flow should result in no flux.");
338 }
339 Util::Test::SubMessage("Test 4: Uniform flow should maintain constant flux",0);
340 } catch (const std::runtime_error& e)
341 {
342 failed++;
343 Util::Test::SubMessage("Test 4: Uniform flow should maintain constant flux",1);
344 }
345
346 return failed;
347 }
348};
349}
350}
351}
352
353#endif
pp_queryclass
#define pp_queryclass(...)
Definition ParmParse.H:107
TEST
#define TEST(x)
Definition Util.H:21
INFO
#define INFO
Definition Util.H:20
IO::ParmParse::query_default
int query_default(std::string name, T &value, T defaultvalue, std::string="", std::string="", int=-1)
Definition ParmParse.H:185
Solver::Local::Riemann::Roe
Roe Riemann Solver based on Gas Dynamics - Culbert B. Laney.
Definition Roe.H:30
Solver::Local::Riemann::Roe::Roe
Roe(IO::ParmParse &pp)
Definition Roe.H:37
Solver::Local::Riemann::Roe::Parse
static void Parse(Roe &value, IO::ParmParse &pp)
Definition Roe.H:48
Solver::Local::Riemann::Roe::Solve
Flux Solve(State lo, State hi, Set::Scalar gamma, Set::Scalar p_ref, Set::Scalar small)
Definition Roe.H:61
Solver::Local::Riemann::Roe::Roe
Roe(IO::ParmParse &pp, std::string name)
Definition Roe.H:35
Solver::Local::Riemann::Roe::name
static constexpr const char * name
Definition Roe.H:34
Solver::Local::Riemann::Roe::Test
static int Test()
Definition Roe.H:236
Set::Scalar
amrex::Real Scalar
Definition Base.H:19
Solver
A bunch of solvers.
Definition CG.H:6
Util::Test::SubMessage
int SubMessage(std::string testname, int failed)
Definition Util.cpp:369
Util::ParallelMessage
void ParallelMessage(std::string file, std::string func, int line, Args const &... args)
Definition Util.H:164
Util::AssertException
AMREX_FORCE_INLINE void AssertException(std::string file, std::string func, int line, std::string smt, bool pass, Args const &... args)
Definition Util.H:233
Util::Warning
void Warning(std::string file, std::string func, int line, Args const &... args)
Definition Util.H:181
Util::Message
void Message(std::string file, std::string func, int line, Args const &... args)
Definition Util.H:141
Util::Exception
void Exception(std::string file, std::string func, int line, Args const &... args)
Definition Util.H:205
Solver::Local::Riemann::Flux::momentum_normal
Set::Scalar momentum_normal
Definition Riemann.H:90
Solver::Local::Riemann::Flux::momentum_tangent
Set::Scalar momentum_tangent
Definition Riemann.H:91
Generated by doxygen 1.9.8