stardis-solver

Solve coupled heat transfers
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commit 019ba70ed45ee809405a22754e5658bda42564c9
parent 01e334bd892b92e0341e5129ff0c3376ecd7ce76
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Tue, 16 Jun 2020 12:31:33 +0200

Add a reference solution to the transcient test

Diffstat:
Msrc/test_sdis_transcient.c | 255++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 239 insertions(+), 16 deletions(-)

diff --git a/src/test_sdis_transcient.c b/src/test_sdis_transcient.c @@ -16,6 +16,8 @@ #include "sdis.h" #include "test_sdis_utils.h" +#include <string.h> + #define UNKNOWN_TEMPERATURE -1 /******************************************************************************* @@ -23,21 +25,25 @@ ******************************************************************************/ struct context { struct sdis_interface* interfs[12]; + const double* boxsz; }; static void get_scaled_position(const size_t ivert, double pos[3], void* context) { + struct context* ctx = context; + CHK(ctx); box_get_position(ivert, pos, context); - pos[0] *= 0.3; - pos[1] *= 0.1; - pos[2] *= 0.2; + pos[0] *= ctx->boxsz[0]; + pos[1] *= ctx->boxsz[1]; + pos[2] *= ctx->boxsz[2]; } static void get_interface(const size_t itri, struct sdis_interface** bound, void* context) { struct context* ctx = context; + CHK(ctx); *bound = ctx->interfs[itri]; } @@ -135,6 +141,196 @@ create_interface } /******************************************************************************* + * Analytical solution + ******************************************************************************/ +static void +fourier_pq + (const size_t nterms_pq, + const double pos[3], + const double sz[3], + const int i0, + const int i1, + const int i2, + double green[2]) +{ + size_t p, q; + CHK(green); + + green[0] = 0; + green[1] = 0; + + FOR_EACH(p, 0, nterms_pq+1) { + FOR_EACH(q, 0, nterms_pq+1) { + const double p2 = (double)(2*p + 1); + const double q2 = (double)(2*q + 1); + double L_sqr, L, tmp; + L_sqr = PI * PI * ((p2*p2)/(sz[i1]*sz[i1]) + (q2*q2)/(sz[i2]*sz[i2])); + L = sqrt(L_sqr); + tmp = sin(PI*p2*pos[i1]/sz[i1]) + * sin(PI*q2*pos[i2]/sz[i2]) + / (sinh(sz[i0]*L)*(p2*q2)); + if(tmp != 0) { + green[0] += sinh(L*(sz[i0]-pos[i0]))*tmp; + green[1] += sinh(L*pos[i0])*tmp; + } + } + } +} + +/* This function computes the Green function between a given probe + * position/time in a parallelepipedic box and each face of this box (within + * the model of a homogeneous boundary condition on each face). */ +static void +green_analytical + (const double box_size[3], + const double probe[3], + const double time, + const double rho, + const double cp, + const double lambda, + double green[7]) +{ + const size_t nterms_fs = 20; /* #terms in the Fourier expansion series */ + const size_t nterms_pq = 100; /* #terms in double p/q sums */ + const size_t nt_pq = (nterms_fs - 1)/2; + double Gs[7], Gi[7], Gtmp[7]; + size_t i, m, n, o, p, q; + double a, b, c; + double alpha; + + CHK(box_size && probe && time >= 0 && green); + + if(time == 0) { + memset(green, 0, sizeof(double[7])); + green[6] = 1; + return; + } + + memset(Gs, 0, sizeof(double[7])); + memset(Gi, 0, sizeof(double[7])); + memset(Gtmp, 0, sizeof(double[7])); + + /* Steady state solution */ + fourier_pq(nterms_pq, probe, box_size, 0, 1, 2, Gtmp+0); /* Faces 0 and 1 */ + fourier_pq(nterms_pq, probe, box_size, 1, 0, 2, Gtmp+2); /* Faces 2 and 3 */ + fourier_pq(nterms_pq, probe, box_size, 2, 1, 0, Gtmp+4); /* Faces 4 and 5 */ + FOR_EACH(i, 0, 6) Gs[i] += 16 * Gtmp[i] / (PI * PI); + + alpha=lambda/(rho*cp); + a=box_size[0]; + b=box_size[1]; + c=box_size[2]; + + /* Transient solution */ + FOR_EACH(m, 0, nterms_fs+1) { + const double beta = PI*(double)m/a; + const double beta_sqr = beta*beta; + const int m_is_even = (m%2 == 0); + + FOR_EACH(n, 0, nterms_fs+1) { + const double gamma = PI*(double)n/b; + const double gamma_sqr = gamma * gamma; + const int n_is_even = (n%2==0); + + FOR_EACH(o, 0, nterms_fs+1) { + const double eta = PI*(double)o/c; + const double eta_sqr = eta*eta; + const double zeta = alpha*(beta_sqr+gamma_sqr+eta_sqr); + const int o_is_even = (o%2==0); + double Fxyzt; + + memset(Gtmp, 0, sizeof(double[7])); + FOR_EACH(p, 0, nt_pq+1) { + FOR_EACH(q, 0, nt_pq+1) { + const double p2 = (double)(2*p + 1); + const double q2 = (double)(2*q + 1); + const double Lx_sqr = PI*PI*((p2*p2)/(b*b)+(q2*q2)/(c*c)); + const double Ly_sqr = PI*PI*((p2*p2)/(a*a)+(q2*q2)/(c*c)); + const double Lz_sqr = PI*PI*((p2*p2)/(b*b)+(q2*q2)/(a*a)); + const double pq = p2*q2; + double itg[11] = {0}; + + itg[1] = 2*q-o+1 == 0 ? -c/2.0 : 0; + itg[2] = eta / (eta_sqr+Lz_sqr); + itg[4] = 2*p-n+1 == 0 ? -b/2.0 : 0; + itg[5] = gamma / (gamma_sqr+Ly_sqr); + itg[7] = beta / (beta_sqr+Lx_sqr); + itg[9] = 2*p-m+1 == 0 ? -a/2.0 : 0; + itg[10] = 2*q-m+1 == 0 ? -a/2.0 : 0; + + if((2*q-o+1==0) && (2*p-n+1==0)) { + const double z1 = itg[1]*itg[4]*itg[7]; + Gtmp[0] += z1/pq; + Gtmp[1] += (z1*pow(-1.0,(double)(m+1)))/pq; + } + if((2*q-o+1==0) && (2*p-m+1==0)) { + const double z2 = itg[1]*itg[9]*itg[5]; + Gtmp[2] += z2/pq; + Gtmp[3] += (z2*pow(-1.0,(double)(n+1)))/pq; + } + if((2*p-n+1==0) && (2*q-m+1==0)) { + const double z3 = itg[4]*itg[10]*itg[2]; + Gtmp[4] += z3/pq; + Gtmp[5] += (z3*pow(-1.0,(double)(o+1)))/pq; + } + } + } + Fxyzt = + sin(probe[0]*beta) + * sin(probe[1]*gamma) + * sin(probe[2]*eta) + * exp(-zeta*time); + + FOR_EACH(i, 0, 6) { + Gi[i] += Gtmp[i] * Fxyzt; + } + if((!m_is_even) && (!n_is_even) && (!o_is_even)) { + Gi[6] += 8.0 * Fxyzt/(beta*gamma*eta); + } + } + } + } + + /* Gi[i], i=0,5: Green of boundary index i */ + FOR_EACH(i, 0, 6) { + Gi[i] = -128.0 * Gi[i]/(a*b*c*PI*PI); + } + + /* Gi[6]: Green of the initial condition */ + Gi[6] = 8.0*Gi[6]/(a*b*c); + + /* Computing total Green function */ + FOR_EACH(i, 0, 7) { + green[i] = Gs[i] + Gi[i]; + } +} + +static double +temperature_analytical + (const double temperature_bounds[6], + const double temperature_init, + const double box_size[3], + const double probe[3], + const double time, + const double rho, + const double cp, + const double lambda) +{ + double green[7]; + double temperature = 0; + size_t i; + CHK(temperature_bounds && temperature_init && box_size[3] && probe); + green_analytical(box_size, probe, time, rho, cp, lambda, green); + + FOR_EACH(i, 0, 6) { + printf("Green for face %lu: %g\n", (unsigned long)i, green[i]); + temperature += green[i] * temperature_bounds[i]; + } + temperature += green[6] * temperature_init; + return temperature; +} + +/******************************************************************************* * Main function ******************************************************************************/ int @@ -154,12 +350,32 @@ main(int argc, char** argv) struct sdis_mc temperature = SDIS_MC_NULL; struct solid* solid_param = NULL; struct context ctx; - const size_t nrealisations = 10000; + const size_t nrealisations = 100000; size_t nfails = 0; double probe[3]; double time[2]; + double Tbounds[6]; + double Tinit; + double Tref; + double boxsz[3]; + double rho, cp, lambda; (void)argc, (void)argv; + /* System description */ + rho = 1700; + cp = 800; + lambda = 1.15; + Tbounds[0] = 280; /* Xmin */ + Tbounds[1] = 290; /* Xmax */ + Tbounds[2] = 310; /* Ymin */ + Tbounds[3] = 270; /* Ymax */ + Tbounds[4] = 300; /* Zmin */ + Tbounds[5] = 320; /* Zmax */ + Tinit = 300; + boxsz[0] = 0.3; + boxsz[1] = 0.1; + boxsz[2] = 0.2; + OK(mem_init_proxy_allocator(&allocator, &mem_default_allocator)); OK(sdis_device_create(NULL, &allocator, SDIS_NTHREADS_DEFAULT, 1, &dev)); @@ -178,11 +394,11 @@ main(int argc, char** argv) OK(sdis_data_create (dev, sizeof(struct solid), ALIGNOF(struct solid), NULL, &data)); solid_param = sdis_data_get(data); - solid_param->rho = 1700; - solid_param->cp = 800; - solid_param->lambda = 1.15; + solid_param->rho = rho; + solid_param->cp = cp; + solid_param->lambda = lambda; solid_param->delta = 1.0/20.0; - solid_param->init_temperature = 300; + solid_param->init_temperature = Tinit; OK(sdis_solid_create(dev, &solid_shader, data, &solid)); OK(sdis_data_ref_put(data)); @@ -190,12 +406,12 @@ main(int argc, char** argv) interf_shader.front.temperature = interface_get_temperature; /* Create the interfaces */ - interfs[0] = create_interface(dev, solid, fluid, &interf_shader, 280);/*Xmin*/ - interfs[1] = create_interface(dev, solid, fluid, &interf_shader, 290);/*Xmax*/ - interfs[2] = create_interface(dev, solid, fluid, &interf_shader, 310);/*Ymin*/ - interfs[3] = create_interface(dev, solid, fluid, &interf_shader, 270);/*Ymax*/ - interfs[4] = create_interface(dev, solid, fluid, &interf_shader, 300);/*Zmin*/ - interfs[5] = create_interface(dev, solid, fluid, &interf_shader, 320);/*Zmax*/ + interfs[0] = create_interface(dev, solid, fluid, &interf_shader, Tbounds[0]); + interfs[1] = create_interface(dev, solid, fluid, &interf_shader, Tbounds[1]); + interfs[2] = create_interface(dev, solid, fluid, &interf_shader, Tbounds[2]); + interfs[3] = create_interface(dev, solid, fluid, &interf_shader, Tbounds[3]); + interfs[4] = create_interface(dev, solid, fluid, &interf_shader, Tbounds[4]); + interfs[5] = create_interface(dev, solid, fluid, &interf_shader, Tbounds[5]); /* Setup the scene context */ ctx.interfs[0] = ctx.interfs[1] = interfs[4]; /* Zmin */ @@ -204,6 +420,7 @@ main(int argc, char** argv) ctx.interfs[6] = ctx.interfs[7] = interfs[1]; /* Xmax */ ctx.interfs[8] = ctx.interfs[9] = interfs[3]; /* Ymax */ ctx.interfs[10] = ctx.interfs[11] = interfs[2]; /* Ymin */ + ctx.boxsz = boxsz; /* Create the box scene */ OK(sdis_scene_create(dev, box_ntriangles, box_get_indices, get_interface, @@ -219,11 +436,17 @@ main(int argc, char** argv) OK(sdis_estimator_get_failure_count(estimator, &nfails)); OK(sdis_estimator_get_temperature(estimator, &temperature)); - printf("Temperature at (%g, %g, %g) m at %g s ~ %g +/- %g\n", - SPLIT3(probe), time[0], temperature.E, temperature.SE); + + Tref = temperature_analytical + (Tbounds, Tinit, boxsz, probe, time[0], rho, cp, lambda); + + printf("Temperature at (%g, %g, %g) m at %g s = %g ~ %g +/- %g\n", + SPLIT3(probe), time[0], Tref, temperature.E, temperature.SE); printf("#failures = %lu/%lu\n", (unsigned long)nfails, (unsigned long)nrealisations); + CHK(eq_eps(Tref, temperature.E, temperature.SE*3)); + OK(sdis_estimator_ref_put(estimator)); OK(sdis_interface_ref_put(interfs[0])); OK(sdis_interface_ref_put(interfs[1]));