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ThermalSolver.cpp
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ThermalSolver.cpp
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#include "stdafx.h"
#include <ctime>
#include <climits>
#include <Eigen/Sparse>
#include "io.h"
#include "ThermalSolver.h"
#include "TimeStepController.h"
#include "config.h"
#include "Field.h"
#include <direct.h>
template<class T>
inline T scalarClamp(T target, T lower, T upper) {
if (target > upper) return upper;
if (target < lower) return lower;
return target;
}
void ThermalSolver::computeVelocityStar(real dt,
Field * vxGuessField, Field * vyGuessField, Field * vzGuessField,
Field * rhoGuessField, Field* rhsRhoField,
Field * vxStarField, Field * vyStarField, Field * vzStarField)
{
// First Step:
// Solve: Du/Dt = 0
advectVelocitySemiLagrange(dt, vxGuessField, vyGuessField, vzGuessField,
vxField, vyField, vzField,
vxStarField, vyStarField, vzStarField);
// Second Step:
// Euler forward u* = u1 + grad(rhs(rho_guess)) * dt
rhsRhoOnAlignedGrid(rhoGuessField, rhsRhoField);
Field* vStarField[3] = {vxStarField, vyStarField, vzStarField};
real* vStarContent[3] = { vxStarField->content, vyStarField->content, vzStarField->content };
for (int d = 0; d < 3; ++d) {
for (int k = (d == 2); k < resZ; ++k) {
for (int j = (d == 1); j < resY; ++j) {
for (int i = (d == 0); i < resX; ++i) {
int vIndex = vStarField[d]->getIndex(i, j, k);
int centerPlus = rhsRhoField->getIndex(i, j, k);
int centerMinus = rhsRhoField->getIndex(i - (d == 0), j - (d == 1), k - (d == 2));
vStarContent[d][vIndex] += (dt / h) * (rhsRhoField->content[centerPlus] -
rhsRhoField->content[centerMinus]);
// Add gravity at y axis.
if (d == 1) {
vStarContent[d][vIndex] -= envGravity * dt;
}
}
}
}
}
}
// Rho Prime is calculated using C.E.
// See rhoprime.docx for more info.
void ThermalSolver::computeRhoPrime(real dt, Field* vxStarField, Field* vyStarField, Field* vzStarField,
Field* rhoGuessField, Field* rhoPrimeField) {
typedef Eigen::SparseMatrix<real> SpMat;
typedef Eigen::Triplet<real> Triplet;
typedef Eigen::VectorXf EVector;
std::vector<Triplet> coefficients;
int totalCells = rhoGuessField->totalSize;
coefficients.reserve(totalCells * 7);
EVector b(totalCells);
real* vxStar = vxStarField->content;
real* vyStar = vyStarField->content;
real* vzStar = vzStarField->content;
real* rhoStar = rhoGuessField->content;
for (int k = 0; k < resZ; ++k) {
for (int j = 0; j < resY; ++j) {
for (int i = 0; i < resX; ++i) {
int center = rhoGuessField->getIndex(i, j, k);
int left = rhoGuessField->getIndexLoopBoundary(i - 1, j, k);
int right = rhoGuessField->getIndexLoopBoundary(i + 1, j, k);
int up = rhoGuessField->getIndexLoopBoundary(i, j + 1, k);
int bottom = rhoGuessField->getIndexLoopBoundary(i, j - 1, k);
int front = rhoGuessField->getIndexLoopBoundary(i, j, k - 1);
int back = rhoGuessField->getIndexLoopBoundary(i, j, k + 1);
real vRight = vxStar[vxStarField->getIndex(i + 1, j, k)];
real vLeft = vxStar[vxStarField->getIndex(i, j, k)];
real vTop = vyStar[vyStarField->getIndex(i, j + 1, k)];
real vBottom = vyStar[vyStarField->getIndex(i, j, k)];
real vBack = vzStar[vzStarField->getIndex(i, j, k + 1)];
real vFront = vzStar[vzStarField->getIndex(i, j, k)];
coefficients.push_back(Triplet(center, center, 2 * h / dt + vRight - vLeft + vTop - vBottom + vBack - vFront));
coefficients.push_back(Triplet(center, right, vRight));
coefficients.push_back(Triplet(center, left, -vLeft));
coefficients.push_back(Triplet(center, up, vTop));
coefficients.push_back(Triplet(center, bottom, -vBottom));
coefficients.push_back(Triplet(center, back, vBack));
coefficients.push_back(Triplet(center, front, -vFront));
real rhs = -((rhoStar[center] + rhoStar[right]) * vRight
- (rhoStar[center] + rhoStar[left]) * vLeft
+ (rhoStar[center] + rhoStar[up]) * vTop
- (rhoStar[center] + rhoStar[bottom]) * vBottom
+ (rhoStar[center] + rhoStar[back]) * vBack
- (rhoStar[center] + rhoStar[front]) * vFront
+ 2 * h / dt * (rhoStar[center] - rhoField->content[center]));
// Should be equivalent to (b << rhs;)
b[center] = rhs;
}
}
}
SpMat A(totalCells, totalCells);
A.setFromTriplets(coefficients.begin(), coefficients.end());
Eigen::BiCGSTAB<SpMat, Eigen::IncompleteLUT<real> > solver;
EVector x;
solver.compute(A);
x = solver.solve(b);
CHECK_EQ(solver.info(), Eigen::Success) << "Solver Failed";
memcpy(rhoPrimeField->content, x.data(), sizeof(real) * totalCells);
}
void ThermalSolver::computeVelocityPrime(real dt,
Field * rhoGuessField, Field * rhsRhoStarField, Field * rhsRhoStarStarField,
Field * vxPrimeField, Field * vyPrimeField, Field * vzPrimeField)
{
// Fill v' border with zero.
fillVelocityFieldBorderZero(vxPrimeField, vyPrimeField, vzPrimeField);
rhsRhoOnAlignedGrid(rhoGuessField, rhsRhoStarStarField);
Field* vPrimeField[3] = { vxPrimeField, vyPrimeField, vzPrimeField };
real* vPrimeContent[3] = { vxPrimeField->content, vyPrimeField->content, vzPrimeField->content };
for (int d = 0; d < 3; ++d) {
for (int k = (d == 2); k < resZ; ++k) {
for (int j = (d == 1); j < resY; ++j) {
for (int i = (d == 0); i < resX; ++i) {
int vIndex = vPrimeField[d]->getIndex(i, j, k);
int centerPlus = rhoGuessField->getIndex(i, j, k);
int centerMinus = rhoGuessField->getIndex(i - (d == 0), j - (d == 1), k - (d == 2));
vPrimeContent[d][vIndex] = (dt / h) * (rhsRhoStarStarField->content[centerPlus] -
rhsRhoStarStarField->content[centerMinus]);
vPrimeContent[d][vIndex] -= (dt / h) * (rhsRhoStarField->content[centerPlus] -
rhsRhoStarField->content[centerMinus]);
// The gravity term cancels.
}
}
}
}
}
real ThermalSolver::updateRhoField(Field * rhoGuess, Field * rhoPrime)
{
real delta = 0.0f;
for (int i = 0; i < rhoGuess->totalSize; ++i) {
rhoGuess->content[i] += rhoRelaxCoef * rhoPrime->content[i];
delta += (rhoPrime->content[i] * rhoPrime->content[i]);
}
return delta;
}
real ThermalSolver::updateVelocityField(Field * vxStarField, Field * vyStarField, Field * vzStarField,
Field * vxPrimeField, Field * vyPrimeField, Field * vzPrimeField,
Field * vxGuessField, Field * vyGuessField, Field * vzGuessField)
{
real delta = 0.0f;
for (int i = 0; i < vxStarField->totalSize; i++) {
real finalVx = vxStarField->content[i] + vxPrimeField->content[i];
real vxDelta = finalVx - vxGuessField->content[i];
vxGuessField->content[i] = finalVx;
delta += vxDelta * vxDelta;
}
for (int i = 0; i < vyStarField->totalSize; i++) {
real finalVy = vyStarField->content[i] + vyPrimeField->content[i];
real vyDelta = finalVy - vyGuessField->content[i];
vyGuessField->content[i] = finalVy;
delta += vyDelta * vyDelta;
}
for (int i = 0; i < vzStarField->totalSize; i++) {
real finalVz = vzStarField->content[i] + vzPrimeField->content[i];
real vzDelta = finalVz - vzGuessField->content[i];
vzGuessField->content[i] = finalVz;
delta += vzDelta * vzDelta;
}
return delta;
}
void ThermalSolver::laplacianFieldOnAlignedGrid(Field* f, Field* lapF)
{
real* fc = f->content;
real* lapFc = lapF->content;
for (int k = 0; k < resZ; ++ k) {
for (int j = 0; j < resY; ++ j) {
for (int i = 0; i < resX; ++ i) {
int center = f->getIndex(i, j, k);
int left = f->getIndexClampBoundary(i - 1, j, k);
int right = f->getIndexClampBoundary(i + 1, j, k);
int up = f->getIndexClampBoundary(i, j + 1, k);
int bottom = f->getIndexClampBoundary(i, j - 1, k);
int front = f->getIndexClampBoundary(i, j, k - 1);
int back = f->getIndexClampBoundary(i, j, k + 1);
lapFc[center] = (fc[left] + fc[right] +
fc[up] + fc[bottom] + fc[front] + fc[back] -
6 * fc[center]) / h / h;
}
}
}
}
void ThermalSolver::rhsRhoOnAlignedGrid(Field * rF, Field * rhsRF)
{
real* rho = rF->content;
real* rhsRho = rhsRF->content;
for (int k = 0; k < resZ; ++k) {
for (int j = 0; j < resY; ++j) {
for (int i = 0; i < resX; ++i) {
int center = rF->getIndex(i, j, k);
int left = rF->getIndexClampBoundary(i - 1, j, k);
int right = rF->getIndexClampBoundary(i + 1, j, k);
int up = rF->getIndexClampBoundary(i, j + 1, k);
int bottom = rF->getIndexClampBoundary(i, j - 1, k);
int front = rF->getIndexClampBoundary(i, j, k - 1);
int back = rF->getIndexClampBoundary(i, j, k + 1);
rhsRho[center] = - isothermalWd(rho[center]);
rhsRho[center] += (vdwInvWe / h / h) * (rho[left] + rho[right] +
rho[up] + rho[bottom] + rho[front] + rho[back] -
6 * rho[center]);
}
}
}
}
void ThermalSolver::advectVelocitySemiLagrange(real dt,
Field * vxBackgroundField, Field * vyBackgroundField, Field * vzBackgroundField,
Field * vxInterimField, Field *vyInterimField, Field *vzInterimField,
Field * vxNewField, Field * vyNewField, Field * vzNewField) {
// Get the content of the fields.
real* vxBackground = vxBackgroundField->content;
real* vyBackground = vyBackgroundField->content;
real* vzBackground = vzBackgroundField->content;
real* vxInterim = vxInterimField->content;
real* vyInterim = vyInterimField->content;
real* vzInterim = vzInterimField->content;
real* vxNew = vxNewField->content;
real* vyNew = vyNewField->content;
real* vzNew = vzNewField->content;
// Fill the velocity at solid still boundaries
fillVelocityFieldBorderZero(vxNewField, vyNewField, vzNewField);
// velocity X
for (int z = 0; z < resZ; z++) {
for (int y = 0; y < resY; y++) {
for (int x = 1; x < resX; x++) {
int index = vxBackgroundField->getIndex(x, y, z);
real velx = vxBackground[index];
real vely = (
vyBackground[vyBackgroundField->getIndex(x - 1, y, z)] +
vyBackground[vyBackgroundField->getIndex(x - 1, y + 1, z)] +
vyBackground[vyBackgroundField->getIndex(x , y , z)] +
vyBackground[vyBackgroundField->getIndex(x , y + 1, z)]) * 0.25f;
real velz = (
vzBackground[vzBackgroundField->getIndex(x , y, z)] +
vzBackground[vzBackgroundField->getIndex(x - 1, y, z)] +
vzBackground[vzBackgroundField->getIndex(x , y, z + 1)] +
vzBackground[vzBackgroundField->getIndex(x - 1, y, z + 1)]) * 0.25f;
// backtrace
real xTrace = x - (dt / h) * velx;
real yTrace = y - (dt / h) * vely;
real zTrace = z - (dt / h) * velz;
// clamp backtrace to grid boundaries
xTrace = scalarClamp(xTrace, 0.0f, (real)resX);
yTrace = scalarClamp(yTrace, -0.5f, (real)(resY - 0.5f));
zTrace = scalarClamp(zTrace, -0.5f, (real)(resZ - 0.5f));
// locate neighbors to interpolate
const int x0 = ifloor(xTrace);
const int x1 = x0 + 1;
const int y0 = ifloor(yTrace);
const int y1 = y0 + 1;
const int z0 = ifloor(zTrace);
const int z1 = z0 + 1;
// get interpolation weights
const real s1 = xTrace - floor(xTrace);
const real s0 = 1.0f - s1;
const real t1 = yTrace - floor(yTrace);
const real t0 = 1.0f - t1;
const real u1 = zTrace - floor(zTrace);
const real u0 = 1.0f - u1;
const int i000 = vxBackgroundField->getIndexClampBoundary(x0, y0, z0);
const int i010 = vxBackgroundField->getIndexClampBoundary(x0, y1, z0);
const int i100 = vxBackgroundField->getIndexClampBoundary(x1, y0, z0);
const int i110 = vxBackgroundField->getIndexClampBoundary(x1, y1, z0);
const int i001 = vxBackgroundField->getIndexClampBoundary(x0, y0, z1);
const int i011 = vxBackgroundField->getIndexClampBoundary(x0, y1, z1);
const int i101 = vxBackgroundField->getIndexClampBoundary(x1, y0, z1);
const int i111 = vxBackgroundField->getIndexClampBoundary(x1, y1, z1);
vxNew[index] = u0 * (s0 * (t0 * vxInterim[i000] +
t1 * vxInterim[i010]) +
s1 * (t0 * vxInterim[i100] +
t1 * vxInterim[i110])) +
u1 * (s0 * (t0 * vxInterim[i001] +
t1 * vxInterim[i011]) +
s1 * (t0 * vxInterim[i101] +
t1 * vxInterim[i111]));
}
}
}
// velocity Y
for (int z = 0; z < resZ; z++) {
for (int y = 1; y < resY; y++) {
for (int x = 0; x < resX; x++) {
int index = vyBackgroundField->getIndex(x, y, z);
real velx = (
vxBackground[vxBackgroundField->getIndex(x, y - 1, z)] +
vxBackground[vxBackgroundField->getIndex(x, y, z)] +
vxBackground[vxBackgroundField->getIndex(x + 1, y - 1, z)] +
vxBackground[vxBackgroundField->getIndex(x + 1, y, z)]) * 0.25f;
real vely = vyBackground[index];
real velz = (
vzBackground[vzBackgroundField->getIndex(x, y, z)] +
vzBackground[vzBackgroundField->getIndex(x, y, z + 1)] +
vzBackground[vzBackgroundField->getIndex(x, y - 1, z)] +
vzBackground[vzBackgroundField->getIndex(x, y - 1, z + 1)]) * 0.25f;
// backtrace
real xTrace = x - (dt / h) * velx;
real yTrace = y - (dt / h) * vely;
real zTrace = z - (dt / h) * velz;
// clamp backtrace to grid boundaries
xTrace = scalarClamp(xTrace, -0.5f, (real)(resX - 0.5f));
yTrace = scalarClamp(yTrace, 0.0f, (real)resY);
zTrace = scalarClamp(zTrace, -0.5f, (real)(resZ - 0.5f));
// locate neighbors to interpolate
const int x0 = ifloor(xTrace);
const int x1 = x0 + 1;
const int y0 = ifloor(yTrace);
const int y1 = y0 + 1;
const int z0 = ifloor(zTrace);
const int z1 = z0 + 1;
// get interpolation weights
const real s1 = xTrace - floor(xTrace);
const real s0 = 1.0f - s1;
const real t1 = yTrace - floor(yTrace);
const real t0 = 1.0f - t1;
const real u1 = zTrace - floor(zTrace);
const real u0 = 1.0f - u1;
const int i000 = vyBackgroundField->getIndexClampBoundary(x0, y0, z0);
const int i010 = vyBackgroundField->getIndexClampBoundary(x0, y1, z0);
const int i100 = vyBackgroundField->getIndexClampBoundary(x1, y0, z0);
const int i110 = vyBackgroundField->getIndexClampBoundary(x1, y1, z0);
const int i001 = vyBackgroundField->getIndexClampBoundary(x0, y0, z1);
const int i011 = vyBackgroundField->getIndexClampBoundary(x0, y1, z1);
const int i101 = vyBackgroundField->getIndexClampBoundary(x1, y0, z1);
const int i111 = vyBackgroundField->getIndexClampBoundary(x1, y1, z1);
// interpolate
vyNew[index] = u0 * (s0 * (t0 * vyInterim[i000] +
t1 * vyInterim[i010]) +
s1 * (t0 * vyInterim[i100] +
t1 * vyInterim[i110])) +
u1 * (s0 * (t0 * vyInterim[i001] +
t1 * vyInterim[i011]) +
s1 * (t0 * vyInterim[i101] +
t1 * vyInterim[i111]));
}
}
}
// velocity Z
for (int z = 1; z < resZ; z++) {
for (int y = 0; y < resY; y++) {
for (int x = 0; x < resX; x++) {
int index = vzBackgroundField->getIndex(x, y, z);
real velx = (
vxBackground[vxBackgroundField->getIndex(x, y, z - 1)] +
vxBackground[vxBackgroundField->getIndex(x, y, z)] +
vxBackground[vxBackgroundField->getIndex(x + 1, y, z - 1)] +
vxBackground[vxBackgroundField->getIndex(x + 1, y, z)]) * 0.25f;
real vely = (
vyBackground[vyBackgroundField->getIndex(x, y, z - 1)] +
vyBackground[vyBackgroundField->getIndex(x, y + 1, z - 1)] +
vyBackground[vyBackgroundField->getIndex(x, y, z)] +
vyBackground[vyBackgroundField->getIndex(x, y + 1, z)]) * 0.25f;
real velz = vzBackground[index];
// backtrace
real xTrace = x - (dt / h) * velx;
real yTrace = y - (dt / h) * vely;
real zTrace = z - (dt / h) * velz;
// clamp backtrace to grid boundaries
xTrace = scalarClamp(xTrace, -0.5f, (real)(resX - 0.5f));
yTrace = scalarClamp(yTrace, -0.5f, (real)(resY - 0.5f));
zTrace = scalarClamp(zTrace, 0.0f, (real)resZ);
// locate neighbors to interpolate
const int x0 = ifloor(xTrace);
const int x1 = x0 + 1;
const int y0 = ifloor(yTrace);
const int y1 = y0 + 1;
const int z0 = ifloor(zTrace);
const int z1 = z0 + 1;
// get interpolation weights
const real s1 = xTrace - floor(xTrace);
const real s0 = 1.0f - s1;
const real t1 = yTrace - floor(yTrace);
const real t0 = 1.0f - t1;
const real u1 = zTrace - floor(zTrace);
const real u0 = 1.0f - u1;
const int i000 = vzBackgroundField->getIndexClampBoundary(x0, y0, z0);
const int i010 = vzBackgroundField->getIndexClampBoundary(x0, y1, z0);
const int i100 = vzBackgroundField->getIndexClampBoundary(x1, y0, z0);
const int i110 = vzBackgroundField->getIndexClampBoundary(x1, y1, z0);
const int i001 = vzBackgroundField->getIndexClampBoundary(x0, y0, z1);
const int i011 = vzBackgroundField->getIndexClampBoundary(x0, y1, z1);
const int i101 = vzBackgroundField->getIndexClampBoundary(x1, y0, z1);
const int i111 = vzBackgroundField->getIndexClampBoundary(x1, y1, z1);
vzNew[index] = u0 * (s0 * (t0 * vzInterim[i000] +
t1 * vzInterim[i010]) +
s1 * (t0 * vzInterim[i100] +
t1 * vzInterim[i110])) +
u1 * (s0 * (t0 * vzInterim[i001] +
t1 * vzInterim[i011]) +
s1 * (t0 * vzInterim[i101] +
t1 * vzInterim[i111]));
}
}
}
}
void ThermalSolver::fillVelocityFieldBorderZero(Field * xF, Field * yF, Field * zF)
{
real* xFc = xF->content;
real* yFc = yF->content;
real* zFc = zF->content;
for (int k = 0; k < resZ; k++) {
for (int j = 0; j < resY; j++) {
xFc[xF->getIndex(0, j, k)] = 0.0f;
xFc[xF->getIndex(resX, j, k)] = 0.0f;
}
}
for (int i = 0; i < resX; i++) {
for (int k = 0; k < resZ; k++) {
yFc[yF->getIndex(i, 0, k)] = 0.0f;
yFc[yF->getIndex(i, resY, k)] = 0.0f;
}
}
for (int i = 0; i < resX; i++) {
for (int j = 0; j < resY; j++) {
zFc[zF->getIndex(i, j, 0)] = 0.0f;
zFc[zF->getIndex(i, j, resZ)] = 0.0f;
}
}
}
void ThermalSolver::run(TimeStepController* timeStep)
{
int& stepCount = timeStep->_stepCount;
int snapshotInterval = config->snapshotInterval();
while (!timeStep->isFinished()) {
std::clock_t startTime = std::clock();
stepSimple(timeStep->getStepDt());
int fmCnt;
if (timeStep->isFrameTime(fmCnt)) {
LOG(INFO) << "Frame " << fmCnt << " generated";
}
std::clock_t endTime = std::clock();
stepCount += 1;
LOG(INFO) << "Time step " << stepCount << " finished, this step took " <<
(real)((endTime - startTime) / CLOCKS_PER_SEC) << "s";
// Write preview to destination folder.
{
std::string baseFolder = config->fieldOutputDir() + "/" + config->runName() + "/";
_mkdir(baseFolder.c_str());
auto getFieldOutputFilename = [&](std::string pfx) {
return baseFolder + pfx + std::to_string(stepCount);
};
rhoField->writeSlabPreviewToFile(getFieldOutputFilename("rho"));
vxField->writeSlabPreviewToFile(getFieldOutputFilename("vx"));
vyField->writeSlabPreviewToFile(getFieldOutputFilename("vy"));
}
// Dump to file every snapshot interval
{
if (stepCount % snapshotInterval == 0) {
std::string baseFolder = config->snapshotOutputDir() + "/" + config->runName() + "/";
_mkdir(baseFolder.c_str());
std::string snapshotFilename = baseFolder + std::to_string(stepCount);
LOG(INFO) << "Dumping solver state to " << snapshotFilename;
io::dumpSolverToFile(snapshotFilename, rhoField, vxField, vyField, vzField, timeStep);
}
}
}
}
ThermalSolver::ThermalSolver(Config * cfg, Field * initRhoField, Field * initVxField,
Field * initVyField, Field * initVzField)
{
resX = cfg->resX();
resY = cfg->resY();
resZ = cfg->resZ();
h = cfg->h();
vdwA = cfg->vdwPA();
vdwB = cfg->vdwPB();
vdwTheta = cfg->vdwTheta();
vdwInvWe = 1.0f / cfg->vdwPWE();
velConvergeTol = cfg->velConvergeTol();
rhoConvergeTol = cfg->rhoConvergeTol();
rhoRelaxCoef = cfg->rhoRelaxCoef();
envGravity = cfg->gravity();
if (initRhoField) rhoField = new Field(initRhoField);
else rhoField = new Field(resX, resY, resZ, true);
if (initVxField) vxField = new Field(initVxField);
else vxField = new Field(resX + 1, resY, resZ, true);
if (initVyField) vyField = new Field(initVyField);
else vyField = new Field(resX, resY + 1, resZ, true);
if (initVzField) vzField = new Field(initVzField);
else vzField = new Field(resX, resY, resZ + 1, true);
config = cfg;
}
void ThermalSolver::stepSimple(real dt)
{
Field* vxGuessField = new Field(vxField);
Field* vyGuessField = new Field(vyField);
Field* vzGuessField = new Field(vzField);
Field* rhoGuessField = new Field(rhoField);
// For vStarField.
Field* vxStarField = new Field(vxField, false);
Field* vyStarField = new Field(vyField, false);
Field* vzStarField = new Field(vzField, false);
Field* rhoPrimeField = new Field(rhoField, false);
// For rhoStarField.
Field* rhsRhoStarField = new Field(rhoField, false);
Field* rhsRhoStarStarField = new Field(rhoField, false);
int loopCount = 0;
real lastRhoDelta = std::numeric_limits<real>::max();
real lastVelDelta = std::numeric_limits<real>::max();
while (true) {
loopCount += 1;
LOG(INFO) << "Inner loop: # " << loopCount;
// 1. Assemble and solve momentum equation for v*
computeVelocityStar(dt, vxGuessField, vyGuessField, vzGuessField, rhoGuessField,
rhsRhoStarField, vxStarField, vyStarField, vzStarField);
// 2. Let rho* = rho Guess
// 3. Assemble and solve continuity equation for rho'
computeRhoPrime(dt, vxStarField, vyStarField, vzStarField, rhoGuessField, rhoPrimeField);
// Correct rho now to be rhoStarStar,
// Notice: only for memory efficiency.
real rhoDelta = updateRhoField(rhoGuessField, rhoPrimeField);
// 4. Compute V prime. (move the news to outer for better performance)
Field* vxPrimeField = new Field(vxField, false);
Field* vyPrimeField = new Field(vyField, false);
Field* vzPrimeField = new Field(vzField, false);
// rhsRhoStarStarField is computed through rhoGuessField
computeVelocityPrime(dt, rhoGuessField,
rhsRhoStarField, rhsRhoStarStarField, vxPrimeField, vyPrimeField, vzPrimeField);
// Correct v field.
real velDelta = updateVelocityField(vxStarField, vyStarField, vzStarField,
vxPrimeField, vyPrimeField, vzPrimeField, vxGuessField, vyGuessField, vzGuessField);
delete vxPrimeField;
delete vyPrimeField;
delete vzPrimeField;
LOG(INFO) << "Rho diff = " << rhoDelta << ", Velocity diff = " << velDelta;
if (rhoDelta < rhoConvergeTol && velDelta < velConvergeTol) {
break;
}
else {
if (rhoDelta > lastRhoDelta || velDelta > lastVelDelta) {
LOG(WARNING) << "Converge Delta reaches its minimum. Stop iteration";
break;
}
else {
lastRhoDelta = rhoDelta;
lastVelDelta = velDelta;
}
}
}
// Update current fields.
rhoField->copyFrom(rhoGuessField);
vxField->copyFrom(vxGuessField);
vyField->copyFrom(vyGuessField);
vzField->copyFrom(vzGuessField);
delete vxGuessField;
delete vyGuessField;
delete vzGuessField;
delete rhoGuessField;
delete vxStarField;
delete vyStarField;
delete vzStarField;
delete rhoPrimeField;
delete rhsRhoStarField;
delete rhsRhoStarStarField;
}
ThermalSolver::~ThermalSolver()
{
delete rhoField;
delete vxField;
delete vyField;
delete vzField;
}