/** Prepare axes for the numerical solver (and if onlyprepare==false) call the
* solver
*/
void Particles::PrepareAndRunNumericalSolver(
vector<vector<double> > &particlespectrum, bool onlyprepare,
bool dontinitialise) {
if (EnergyAxisUpperBoundary) {
GetAxis(Emin, EnergyAxisUpperBoundary, ebins, energyAxis, true);
} else if (EnergyAxisLowerBoundary) {
GetAxis(EnergyAxisLowerBoundary, eMax, ebins, energyAxis, true);
} else if (EnergyAxisLowerBoundary && EnergyAxisUpperBoundary) {
GetAxis(EnergyAxisLowerBoundary, EnergyAxisUpperBoundary, ebins, energyAxis,
true);
} else {
GetAxis(Emin, eMax, ebins, energyAxis, true);
}
CreateGrid();
if (dontinitialise == false) SetInitialCondition(grid, energyAxis, Tmin);
/* if onlyprepare=true, only the axes are initialised, but the grid is not
* computed
* until t=age. This is useful in conjunction with
* ComputeGridInTimeInterval().
*/
if (onlyprepare == false) ComputeGrid(grid, energyAxis, Tmin, Age, timeAxis);
return;
}
int main(int argc, char **argv)
{
MPI_Comm comm;
PetscMPIInt rank;
PetscErrorCode ierr;
User user;
PetscLogDouble v1, v2;
PetscInt nplot = 0;
char filename1[2048], fileName[2048];
PetscBool set = PETSC_FALSE;
PetscInt steps_output;
ierr = PetscInitialize(&argc, &argv, (char*) 0, help);CHKERRQ(ierr);
comm = PETSC_COMM_WORLD;
ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
ierr = PetscNew(&user);CHKERRQ(ierr);
ierr = PetscNew(&user->algebra);CHKERRQ(ierr);
ierr = PetscNew(&user->model);CHKERRQ(ierr);
ierr = PetscNew(&user->model->physics);CHKERRQ(ierr);
Algebra algebra = user->algebra;
ierr = LoadOptions(comm, user);CHKERRQ(ierr);
ierr = PetscTime(&v1);CHKERRQ(ierr);
ierr = CreateMesh(comm, user);CHKERRQ(ierr);
ierr = PetscTime(&v2);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,
"Read and Distribute mesh takes %f sec \n", v2 - v1);CHKERRQ(ierr);
ierr = SetUpLocalSpace(user);CHKERRQ(ierr); //Set up the dofs of each element
ierr = ConstructGeometryFVM(&user->facegeom, &user->cellgeom, user);CHKERRQ(ierr);
ierr = LimiterSetup(user);CHKERRQ(ierr);
if(user->output_solution){
// the output file options
ierr = PetscOptionsBegin(PETSC_COMM_WORLD,0,"Options for output solution",0);CHKERRQ(ierr);
ierr = PetscOptionsString("-solutionfile", "solution file", "AeroSim.c", filename1,filename1, 2048, &set);CHKERRQ(ierr);
if(!set){SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_NULL,"please use option -solutionfile to specify solution file name \n");}
ierr = PetscOptionsInt("-steps_output", "the number of time steps between two outputs", "", steps_output, &steps_output, &set);CHKERRQ(ierr);
if(!set){ steps_output = 1;}
ierr = PetscOptionsEnd();CHKERRQ(ierr);
}
if (user->TimeIntegralMethod == EXPLICITMETHOD) {
if(user->myownexplicitmethod){
ierr = PetscPrintf(PETSC_COMM_WORLD,"Using the fully explicit method based on my own routing\n");CHKERRQ(ierr);
user->current_time = user->initial_time;
user->current_step = 1;
ierr = DMCreateGlobalVector(user->dm, &algebra->solution);CHKERRQ(ierr);
ierr = PetscObjectSetName((PetscObject) algebra->solution, "solution");CHKERRQ(ierr);
ierr = SetInitialCondition(user->dm, algebra->solution, user);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->fn);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->oldsolution);CHKERRQ(ierr);
if(user->Explicit_RK2){
ierr = PetscPrintf(PETSC_COMM_WORLD,"Use the second order Runge Kutta method \n");CHKERRQ(ierr);
}else{
ierr = PetscPrintf(PETSC_COMM_WORLD,"Use the first order forward Euler method \n");CHKERRQ(ierr);
}
nplot = 0; //the plot step
while(user->current_time < (user->final_time - 0.05 * user->dt)){
user->current_time = user->current_time + user->dt;
ierr = FormTimeStepFunction(user, algebra, algebra->solution, algebra->fn);CHKERRQ(ierr);
PetscReal fnnorm;
ierr = VecNorm(algebra->fn,NORM_INFINITY,&fnnorm);CHKERRQ(ierr);
if(0){
PetscViewer viewer;
ierr = OutputVTK(user->dm, "function.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->fn, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Step %D at time %g with founction norm = %g \n",
user->current_step, user->current_time, fnnorm);CHKERRQ(ierr);
//break;
}
if(user->Explicit_RK2){
ierr = VecCopy(algebra->solution, algebra->oldsolution);CHKERRQ(ierr);//U^n
ierr = VecAXPY(algebra->solution, user->dt, algebra->fn);CHKERRQ(ierr);//U^{(1)}
ierr = FormTimeStepFunction(user, algebra, algebra->solution, algebra->fn);CHKERRQ(ierr);//f(U^{(1)})
ierr = VecAXPY(algebra->solution, 1.0, algebra->oldsolution);CHKERRQ(ierr);//U^n + U^{(1)}
ierr = VecAXPY(algebra->solution, user->dt, algebra->fn);CHKERRQ(ierr);// + dt*f(U^{(1)})
ierr = VecScale(algebra->solution, 0.5);CHKERRQ(ierr);
}else{
ierr = VecCopy(algebra->solution, algebra->oldsolution);CHKERRQ(ierr);
ierr = VecAXPY(algebra->solution, user->dt, algebra->fn);CHKERRQ(ierr);
}
{// Monitor the solution and function norms
PetscReal norm;
PetscLogDouble space =0;
PetscInt size;
ierr = VecNorm(algebra->solution,NORM_INFINITY,&norm);CHKERRQ(ierr);
ierr = VecGetSize(algebra->solution, &size);CHKERRQ(ierr);
norm = norm/size;
if (norm>1.e5) {
SETERRQ2(PETSC_COMM_WORLD, PETSC_ERR_LIB,
"The norm of the solution is: %f (current time: %f). The explicit method is going to DIVERGE!!!", norm, user->current_time);
}
if (user->current_step%10==0) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Step %D at time %g with solution norm = %g and founction norm = %g \n",
user->current_step, user->current_time, norm, fnnorm);CHKERRQ(ierr);
}
ierr = PetscMallocGetCurrentUsage(&space);CHKERRQ(ierr);
// if (user->current_step%10==0) {
// ierr = PetscPrintf(PETSC_COMM_WORLD,"Current space PetscMalloc()ed %g M\n",
// space/(1024*1024));CHKERRQ(ierr);
// }
}
{ // Monitor the difference of two steps' solution
PetscReal norm;
ierr = VecAXPY(algebra->oldsolution, -1, algebra->solution);CHKERRQ(ierr);
ierr = VecNorm(algebra->oldsolution,NORM_INFINITY,&norm);CHKERRQ(ierr);
if (user->current_step%10==0) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Step %D at time %g with ||u_k-u_{k-1}|| = %g \n",
user->current_step, user->current_time, norm);CHKERRQ(ierr);
}
if((norm<1.e-6)||(user->current_step > user->max_time_its)) break;
}
// output the solution
if (user->output_solution && (user->current_step%steps_output==0)){
PetscViewer viewer;
// update file name for the current time step
ierr = PetscSNPrintf(fileName, sizeof(fileName),"%s_%d.vtk",filename1, nplot);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Outputing solution %s (current time %f)\n", fileName, user->current_time);CHKERRQ(ierr);
ierr = OutputVTK(user->dm, fileName, &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->solution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
nplot++;
}
user->current_step++;
}
ierr = VecDestroy(&algebra->fn);CHKERRQ(ierr);
}else{
PetscReal ftime;
TS ts;
TSConvergedReason reason;
PetscInt nsteps;
ierr = PetscPrintf(PETSC_COMM_WORLD,"Using the fully explicit method based on the PETSC TS routing\n");CHKERRQ(ierr);
ierr = DMCreateGlobalVector(user->dm, &algebra->solution);CHKERRQ(ierr);
ierr = PetscObjectSetName((PetscObject) algebra->solution, "solution");CHKERRQ(ierr);
ierr = SetInitialCondition(user->dm, algebra->solution, user);CHKERRQ(ierr);
ierr = TSCreate(comm, &ts);CHKERRQ(ierr);
ierr = TSSetType(ts, TSEULER);CHKERRQ(ierr);
ierr = TSSetDM(ts, user->dm);CHKERRQ(ierr);
ierr = TSMonitorSet(ts,TSMonitorFunctionError,&user,NULL);CHKERRQ(ierr);
ierr = TSSetRHSFunction(ts, NULL, MyRHSFunction, user);CHKERRQ(ierr);
ierr = TSSetDuration(ts, 1000, user->final_time);CHKERRQ(ierr);
ierr = TSSetInitialTimeStep(ts, user->initial_time, user->dt);CHKERRQ(ierr);
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
ierr = TSSolve(ts, algebra->solution);CHKERRQ(ierr);
ierr = TSGetSolveTime(ts, &ftime);CHKERRQ(ierr);
ierr = TSGetTimeStepNumber(ts, &nsteps);CHKERRQ(ierr);
ierr = TSGetConvergedReason(ts, &reason);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"%s at time %g after %D steps\n",TSConvergedReasons[reason],ftime,nsteps);CHKERRQ(ierr);
ierr = TSDestroy(&ts);CHKERRQ(ierr);
}
if(user->benchmark_couette) {
ierr = DMCreateGlobalVector(user->dm, &algebra->exactsolution);CHKERRQ(ierr);
ierr = ComputeExactSolution(user->dm, user->final_time, algebra->exactsolution, user);CHKERRQ(ierr);
}
if (user->output_solution){
PetscViewer viewer;
ierr = OutputVTK(user->dm, "solution.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->solution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
}
if(user->benchmark_couette) {
PetscViewer viewer;
PetscReal norm;
ierr = OutputVTK(user->dm, "exact_solution.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
ierr = VecAXPY(algebra->exactsolution, -1, algebra->solution);CHKERRQ(ierr);
ierr = VecNorm(algebra->exactsolution,NORM_INFINITY,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Final time at %f, Error: ||u_k-u|| = %g \n", user->final_time, norm);CHKERRQ(ierr);
ierr = OutputVTK(user->dm, "Error.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
}
ierr = VecDestroy(&algebra->solution);CHKERRQ(ierr);
ierr = VecDestroy(&algebra->oldsolution);CHKERRQ(ierr);
ierr = DMDestroy(&user->dm);CHKERRQ(ierr);
} else if (user->TimeIntegralMethod == IMPLICITMETHOD) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Using the fully implicit method\n");CHKERRQ(ierr);
ierr = SNESCreate(comm,&user->snes);CHKERRQ(ierr);
ierr = SNESSetDM(user->snes,user->dm);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(user->dm, &algebra->solution);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->oldsolution);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->f);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->fn);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->oldfn);CHKERRQ(ierr);
ierr = PetscObjectSetName((PetscObject) algebra->solution, "solution");CHKERRQ(ierr);
ierr = SetInitialCondition(user->dm, algebra->solution, user);CHKERRQ(ierr);
ierr = DMSetMatType(user->dm, MATAIJ);CHKERRQ(ierr);
// ierr = DMCreateMatrix(user->dm, &algebra->A);CHKERRQ(ierr);
ierr = DMCreateMatrix(user->dm, &algebra->J);CHKERRQ(ierr);
if (user->JdiffP) {
/*Set up the preconditioner matrix*/
ierr = DMCreateMatrix(user->dm, &algebra->P);CHKERRQ(ierr);
}else{
algebra->P = algebra->J;
}
ierr = MatSetOption(algebra->J, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE);CHKERRQ(ierr);
/*set nonlinear function */
ierr = SNESSetFunction(user->snes, algebra->f, FormFunction, (void*)user);CHKERRQ(ierr);
/* compute Jacobian */
ierr = SNESSetJacobian(user->snes, algebra->J, algebra->P, FormJacobian, (void*)user);CHKERRQ(ierr);
ierr = SNESSetFromOptions(user->snes);CHKERRQ(ierr);
/* do the solve */
if (user->timestep == TIMESTEP_STEADY_STATE) {
ierr = SolveSteadyState(user);CHKERRQ(ierr);
} else {
ierr = SolveTimeDependent(user);CHKERRQ(ierr);
}
if (user->output_solution){
PetscViewer viewer;
ierr = OutputVTK(user->dm, "solution.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->solution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
}
if(user->benchmark_couette) {
PetscViewer viewer;
PetscReal norm;
ierr = OutputVTK(user->dm, "exact_solution.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
ierr = VecAXPY(algebra->exactsolution, -1, algebra->solution);CHKERRQ(ierr);
ierr = VecNorm(algebra->exactsolution,NORM_INFINITY,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Error: ||u_k-u|| = %g \n", norm);CHKERRQ(ierr);
ierr = OutputVTK(user->dm, "Error.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
}
ierr = VecDestroy(&algebra->solution);CHKERRQ(ierr);
ierr = VecDestroy(&algebra->f);CHKERRQ(ierr);
ierr = VecDestroy(&algebra->oldsolution);CHKERRQ(ierr);
ierr = VecDestroy(&algebra->fn);CHKERRQ(ierr);
ierr = VecDestroy(&algebra->oldfn);CHKERRQ(ierr);
ierr = SNESDestroy(&user->snes);CHKERRQ(ierr);
ierr = DMDestroy(&user->dm);CHKERRQ(ierr);
} else {
SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"WRONG option for the time integral method. Using the option '-time_integral_method 0 or 1'");
}
ierr = VecDestroy(&user->cellgeom);CHKERRQ(ierr);
ierr = VecDestroy(&user->facegeom);CHKERRQ(ierr);
ierr = DMDestroy(&user->dmGrad);CHKERRQ(ierr);
ierr = PetscFunctionListDestroy(&LimitList);CHKERRQ(ierr);
ierr = PetscFree(user->model->physics);CHKERRQ(ierr);
ierr = PetscFree(user->algebra);CHKERRQ(ierr);
ierr = PetscFree(user->model);CHKERRQ(ierr);
ierr = PetscFree(user);CHKERRQ(ierr);
{
PetscLogDouble space =0;
ierr = PetscMallocGetCurrentUsage(&space);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Unfreed space at the End %g M\n", space/(1024*1024));CHKERRQ(ierr);
}
ierr = PetscFinalize();
return(0);
}
int main(int argc, char **argv)
{
MPI_Comm comm;
PetscMPIInt rank;
PetscErrorCode ierr;
User user;
PetscLogDouble v1, v2;
PetscInt nplot = 0;
char fileName[2048];
ierr = PetscInitialize(&argc, &argv, (char*) 0, help);CHKERRQ(ierr);
comm = PETSC_COMM_WORLD;
ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
ierr = PetscNew(&user);CHKERRQ(ierr);
ierr = PetscNew(&user->algebra);CHKERRQ(ierr);
ierr = PetscNew(&user->model);CHKERRQ(ierr);
ierr = PetscNew(&user->model->physics);CHKERRQ(ierr);
Algebra algebra = user->algebra;
ierr = LoadOptions(comm, user);CHKERRQ(ierr);
ierr = PetscTime(&v1);CHKERRQ(ierr);
ierr = CreateMesh(comm, user);CHKERRQ(ierr);
ierr = PetscTime(&v2);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,
"Read and Distribute mesh takes %f sec \n", v2 - v1);CHKERRQ(ierr);
ierr = SetUpLocalSpace(user);CHKERRQ(ierr); //Set up the dofs of each element
ierr = ConstructGeometryFVM(&user->facegeom, &user->cellgeom, user);CHKERRQ(ierr);
ierr = LimiterSetup(user);CHKERRQ(ierr);
if (user->TimeIntegralMethod == EXPLICITMETHOD) { // explicit method
if(user->myownexplicitmethod){// Using the fully explicit method based on my own routing
ierr = PetscPrintf(PETSC_COMM_WORLD,"Using the fully explicit method based on my own routing\n");CHKERRQ(ierr);
user->current_time = user->initial_time;
user->current_step = 1;
ierr = DMCreateGlobalVector(user->dm, &algebra->solution);CHKERRQ(ierr);
ierr = PetscObjectSetName((PetscObject) algebra->solution, "solution");CHKERRQ(ierr);
ierr = VecSet(algebra->solution, 0);CHKERRQ(ierr);
ierr = SetInitialCondition(user->dm, algebra->solution, user);CHKERRQ(ierr);
if(1){
PetscViewer viewer;
ierr = OutputVTK(user->dm, "intialcondition.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->solution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Outputing the initial condition intialcondition.vtk!!! \n");CHKERRQ(ierr);
}
ierr = VecDuplicate(algebra->solution, &algebra->fn);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->oldsolution);CHKERRQ(ierr);
if(user->Explicit_RK2||user->Explicit_RK4){
ierr = PetscPrintf(PETSC_COMM_WORLD,"Use the second order Runge Kutta method \n");CHKERRQ(ierr);
}else{
ierr = PetscPrintf(PETSC_COMM_WORLD,"Use the first order forward Euler method \n");CHKERRQ(ierr);
}
nplot = 0; //the plot step
while(user->current_time < (user->final_time - 0.05 * user->dt)){
user->current_time = user->current_time + user->dt;
ierr = FormTimeStepFunction(user, algebra, algebra->solution, algebra->fn);CHKERRQ(ierr);
if(0){
PetscViewer viewer;
ierr = OutputVTK(user->dm, "function.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->fn, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
}
if(user->Explicit_RK2){
/*
U^n_1 = U^n + 0.5*dt*f(U^n)
U^{n+1} = U^n + dt*f(U^n_1)
*/
ierr = VecCopy(algebra->solution, algebra->oldsolution);CHKERRQ(ierr);
//note that algebra->oldsolution and algebra->solution are both U^n
ierr = VecAXPY(algebra->solution, 0.5*user->dt, algebra->fn);CHKERRQ(ierr);
//U^n_1 = U^n + 0.5*dt*f(U^n), now algebra->solution is U^n_1, and algebra->fn is f(U^n)
ierr = FormTimeStepFunction(user, algebra, algebra->solution, algebra->fn);CHKERRQ(ierr);
//algebra->fn is f(U^n_1)
// reset the algebra->solution to U^n
ierr = VecCopy(algebra->oldsolution, algebra->solution);CHKERRQ(ierr);
ierr = VecAXPY(algebra->solution, user->dt, algebra->fn);CHKERRQ(ierr);
// now algebra->solution is U^{n+1} = U^n + dt*f(U^n_1)
}else if(user->Explicit_RK4){
/* refer to https://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods
k_1 = f(U^n)
U^n_1 = U^n + 0.5*dt*k_1
k_2 = f(U^n_1)
U^n_2 = U^n + 0.5*dt*k_2
k_3 = f(U^n_2)
U^n_3 = U^n + 0.5*dt*k_3
k_4 = f(U^n_3)
U^{n+1} = U^n + dt/6*(k_1 + 2*k_2 + 2*k_3 + k_4)
*/
Vec VecTemp; // store the U^n_1
Vec k1, k2, k3, k4;
ierr = VecDuplicate(algebra->solution, &k1);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &k2);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &k3);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &k4);CHKERRQ(ierr);
ierr = VecCopy(algebra->solution, algebra->oldsolution);CHKERRQ(ierr);
ierr = VecCopy(algebra->fn, k1);CHKERRQ(ierr);
//note that algebra->oldsolution and algebra->solution are both U^n
ierr = VecAXPY(algebra->solution, 0.5*user->dt, k1);CHKERRQ(ierr);
//U^n_1 = U^n + 0.5*dt*k1, now algebra->solution is U^n_1, and algebra->fn is f(U^n)
ierr = FormTimeStepFunction(user, algebra, algebra->solution, algebra->fn);CHKERRQ(ierr);
//algebra->fn is f(U^n_1)
ierr = VecCopy(algebra->fn, k2);CHKERRQ(ierr);
// reset the algebra->solution to U^n
ierr = VecCopy(algebra->oldsolution, algebra->solution);CHKERRQ(ierr);
ierr = VecAXPY(algebra->solution, 0.5*user->dt, k2);CHKERRQ(ierr);
//U^n_2 = U^n + 0.5*dt*k2, now algebra->solution is U^n_2, and algebra->fn is f(U^n_1)
ierr = FormTimeStepFunction(user, algebra, algebra->solution, algebra->fn);CHKERRQ(ierr);
//algebra->fn is f(U^n_2)
ierr = VecCopy(algebra->fn, k3);CHKERRQ(ierr);
// reset the algebra->solution to U^n
ierr = VecCopy(algebra->oldsolution, algebra->solution);CHKERRQ(ierr);
ierr = VecAXPY(algebra->solution, 0.5*user->dt, k3);CHKERRQ(ierr);
//U^n_3 = U^n + 0.5*dt*k3, now algebra->solution is U^n_3, and algebra->fn is f(U^n_2)
ierr = FormTimeStepFunction(user, algebra, algebra->solution, algebra->fn);CHKERRQ(ierr);
//algebra->fn is f(U^n_3)
ierr = VecCopy(algebra->fn, k4);CHKERRQ(ierr);
//U^{n+1} = U^n + dt/6*(k_1 + 2*k_2 + 2*k_3 + k_4)
PetscReal temp;
temp = user->dt/6;
// reset the algebra->solution to U^n
ierr = VecCopy(algebra->oldsolution, algebra->solution);CHKERRQ(ierr);
ierr = VecAXPY(algebra->solution, temp, k1);CHKERRQ(ierr);
// now algebra->solution is U^n + dt/6*k_1
ierr = VecAXPY(algebra->solution, 2*temp, k2);CHKERRQ(ierr);
// now algebra->solution is U^n + dt/6*k_1 + 2*dt/6*k_2
ierr = VecAXPY(algebra->solution, 2*temp, k3);CHKERRQ(ierr);
// now algebra->solution is U^n + dt/6*k_1 + 2*dt/6*k_2 + 2*dt/6*k_3
ierr = VecAXPY(algebra->solution, temp, k4);CHKERRQ(ierr);
// now algebra->solution is U^n + dt/6*k_1 + 2*dt/6*k_2 + 2*dt/6*k_3 + dt/6*k_4
ierr = VecDestroy(&k1);CHKERRQ(ierr);
ierr = VecDestroy(&k2);CHKERRQ(ierr);
ierr = VecDestroy(&k3);CHKERRQ(ierr);
ierr = VecDestroy(&k4);CHKERRQ(ierr);
}else{
ierr = VecCopy(algebra->solution, algebra->oldsolution);CHKERRQ(ierr);
ierr = VecAXPY(algebra->solution, user->dt, algebra->fn);CHKERRQ(ierr);
}
{// Monitor the solution and function norms
PetscReal norm;
PetscLogDouble space =0;
PetscInt size;
PetscReal fnnorm;
ierr = VecNorm(algebra->fn,NORM_2,&fnnorm);CHKERRQ(ierr);
//ierr = VecView(algebra->fn, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = VecNorm(algebra->solution,NORM_2,&norm);CHKERRQ(ierr);
ierr = VecGetSize(algebra->solution, &size);CHKERRQ(ierr);
norm = norm/size;
fnnorm = fnnorm/size;
if (norm>1.e5) {
SETERRQ2(PETSC_COMM_WORLD, PETSC_ERR_LIB,
"The norm of the solution is: %f (current time: %f). The explicit method is going to DIVERGE!!!", norm, user->current_time);
}
if (user->current_step%10==0) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Step %D at time %g with solution norm = %g and founction norm = %g \n",
user->current_step, user->current_time, norm, fnnorm);CHKERRQ(ierr);
}
// ierr = PetscMallocGetCurrentUsage(&space);CHKERRQ(ierr);
// if (user->current_step%10==0) {
// ierr = PetscPrintf(PETSC_COMM_WORLD,"Current space PetscMalloc()ed %g M\n",
// space/(1024*1024));CHKERRQ(ierr);
// }
}
{ // Monitor the difference of two steps' solution
PetscReal norm;
ierr = VecAXPY(algebra->oldsolution, -1, algebra->solution);CHKERRQ(ierr);
ierr = VecNorm(algebra->oldsolution,NORM_2,&norm);CHKERRQ(ierr);
if (user->current_step%10==0) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Step %D at time %g with ||u_k-u_{k-1}|| = %g \n",
user->current_step, user->current_time, norm);CHKERRQ(ierr);
}
if((norm<1.e-6)||(user->current_step > user->max_time_its)){
if(norm<1.e-6) ierr = PetscPrintf(PETSC_COMM_WORLD,"\n Convergence with ||u_k-u_{k-1}|| = %g < 1.e-6\n\n", norm);CHKERRQ(ierr);
if(user->current_step > user->max_time_its) ierr = PetscPrintf(PETSC_COMM_WORLD,"\n Convergence with reaching the max time its\n\n");CHKERRQ(ierr);
break;
}
}
// output the solution
if (user->output_solution && (user->current_step%user->steps_output==0)){
PetscViewer viewer;
Vec solution_unscaled; // Note the the algebra->solution is scaled by the density, so this is for the unscaled solution
nplot = user->current_step/user->steps_output;
// update file name for the current time step
ierr = VecDuplicate(algebra->solution, &solution_unscaled);CHKERRQ(ierr);
ierr = ReformatSolution(algebra->solution, solution_unscaled, user);CHKERRQ(ierr);
ierr = PetscSNPrintf(fileName, sizeof(fileName),"%s_%d.vtk",user->solutionfile, nplot);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Outputing solution %s (current time %f)\n", fileName, user->current_time);CHKERRQ(ierr);
ierr = OutputVTK(user->dm, fileName, &viewer);CHKERRQ(ierr);
ierr = VecView(solution_unscaled, viewer);CHKERRQ(ierr);
ierr = VecDestroy(&solution_unscaled);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
}
user->current_step++;
}
ierr = VecDestroy(&algebra->fn);CHKERRQ(ierr);
}else{ // Using the fully explicit method based on the PETSC TS routing
PetscReal ftime;
TS ts;
TSConvergedReason reason;
PetscInt nsteps;
//PetscReal minRadius;
//ierr = DMPlexTSGetGeometry(user->dm, NULL, NULL, &minRadius);CHKERRQ(ierr);
//user->dt = 0.9*4 * minRadius / 1.0;
ierr = PetscPrintf(PETSC_COMM_WORLD,"Using the fully explicit method based on the PETSC TS routing\n");CHKERRQ(ierr);
ierr = DMCreateGlobalVector(user->dm, &algebra->solution);CHKERRQ(ierr);
ierr = PetscObjectSetName((PetscObject) algebra->solution, "solution");CHKERRQ(ierr);
ierr = VecSet(algebra->solution, 0.0);CHKERRQ(ierr);
ierr = SetInitialCondition(user->dm, algebra->solution, user);CHKERRQ(ierr);
ierr = TSCreate(comm, &ts);CHKERRQ(ierr);
ierr = TSSetType(ts, TSEULER);CHKERRQ(ierr);
ierr = TSSetDM(ts, user->dm);CHKERRQ(ierr);
ierr = TSMonitorSet(ts,TSMonitorFunctionError,(void*)user,NULL);CHKERRQ(ierr);
ierr = TSSetRHSFunction(ts, NULL, MyRHSFunction, user);CHKERRQ(ierr);
ierr = TSSetDuration(ts, 1000, user->final_time);CHKERRQ(ierr);
ierr = TSSetInitialTimeStep(ts, user->initial_time, user->dt);CHKERRQ(ierr);
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
ierr = TSSolve(ts, algebra->solution);CHKERRQ(ierr);
ierr = TSGetSolveTime(ts, &ftime);CHKERRQ(ierr);
ierr = TSGetTimeStepNumber(ts, &nsteps);CHKERRQ(ierr);
ierr = TSGetConvergedReason(ts, &reason);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"%s at time %g after %D steps\n",TSConvergedReasons[reason],ftime,nsteps);CHKERRQ(ierr);
ierr = TSDestroy(&ts);CHKERRQ(ierr);
}
if(user->benchmark_couette) {
ierr = DMCreateGlobalVector(user->dm, &algebra->exactsolution);CHKERRQ(ierr);
ierr = ComputeExactSolution(user->dm, user->current_time, algebra->exactsolution, user);CHKERRQ(ierr);
}
if(user->benchmark_couette) {
PetscViewer viewer;
PetscReal norm;
ierr = OutputVTK(user->dm, "exact_solution.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
ierr = VecAXPY(algebra->exactsolution, -1, algebra->solution);CHKERRQ(ierr);
ierr = VecNorm(algebra->exactsolution,NORM_INFINITY,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Final time at %f, Error: ||u_k-u|| = %g \n", user->current_time, norm);CHKERRQ(ierr);
ierr = OutputVTK(user->dm, "Error.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
}
ierr = VecDestroy(&algebra->solution);CHKERRQ(ierr);
if(user->myownexplicitmethod){ierr = VecDestroy(&algebra->oldsolution);CHKERRQ(ierr);}
ierr = VecDestroy(&algebra->exactsolution);CHKERRQ(ierr);
ierr = DMDestroy(&user->dm);CHKERRQ(ierr);
} else if (user->TimeIntegralMethod == IMPLICITMETHOD) { // Using the fully implicit method
ierr = PetscPrintf(PETSC_COMM_WORLD,"Using the fully implicit method\n");CHKERRQ(ierr);
ierr = SNESCreate(comm,&user->snes);CHKERRQ(ierr);
ierr = SNESSetDM(user->snes,user->dm);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(user->dm, &algebra->solution);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->oldsolution);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->f);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->fn);CHKERRQ(ierr);
ierr = VecDuplicate(algebra->solution, &algebra->oldfn);CHKERRQ(ierr);
ierr = PetscObjectSetName((PetscObject) algebra->solution, "solution");CHKERRQ(ierr);
ierr = SetInitialCondition(user->dm, algebra->solution, user);CHKERRQ(ierr);
ierr = DMSetMatType(user->dm, MATAIJ);CHKERRQ(ierr);
// ierr = DMCreateMatrix(user->dm, &algebra->A);CHKERRQ(ierr);
ierr = DMCreateMatrix(user->dm, &algebra->J);CHKERRQ(ierr);
if (user->JdiffP) {
/*Set up the preconditioner matrix*/
ierr = DMCreateMatrix(user->dm, &algebra->P);CHKERRQ(ierr);
}else{
algebra->P = algebra->J;
}
ierr = MatSetOption(algebra->J, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE);CHKERRQ(ierr);
/*set nonlinear function */
ierr = SNESSetFunction(user->snes, algebra->f, FormFunction, (void*)user);CHKERRQ(ierr);
/* compute Jacobian */
ierr = SNESSetJacobian(user->snes, algebra->J, algebra->P, FormJacobian, (void*)user);CHKERRQ(ierr);
ierr = SNESSetFromOptions(user->snes);CHKERRQ(ierr);
/* do the solve */
if (user->timestep == TIMESTEP_STEADY_STATE) {
ierr = SolveSteadyState(user);CHKERRQ(ierr);
} else {
ierr = SolveTimeDependent(user);CHKERRQ(ierr);
}
if (user->output_solution){
PetscViewer viewer;
Vec solution_unscaled; // Note the the algebra->solution is scaled by the density, so this is for the unscaled solution
ierr = VecDuplicate(algebra->solution, &solution_unscaled);CHKERRQ(ierr);
ierr = ReformatSolution(algebra->solution, solution_unscaled, user);CHKERRQ(ierr);
ierr = OutputVTK(user->dm, "solution.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(solution_unscaled, viewer);CHKERRQ(ierr);
ierr = VecDestroy(&solution_unscaled);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
}
if(user->benchmark_couette) {
PetscViewer viewer;
PetscReal norm;
ierr = OutputVTK(user->dm, "exact_solution.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
ierr = VecAXPY(algebra->exactsolution, -1, algebra->solution);CHKERRQ(ierr);
ierr = VecNorm(algebra->exactsolution,NORM_INFINITY,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Error: ||u_k-u|| = %g \n", norm);CHKERRQ(ierr);
ierr = OutputVTK(user->dm, "Error.vtk", &viewer);CHKERRQ(ierr);
ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
}
ierr = VecDestroy(&algebra->solution);CHKERRQ(ierr);
ierr = VecDestroy(&algebra->f);CHKERRQ(ierr);
ierr = VecDestroy(&algebra->oldsolution);CHKERRQ(ierr);
ierr = VecDestroy(&algebra->fn);CHKERRQ(ierr);
ierr = VecDestroy(&algebra->oldfn);CHKERRQ(ierr);
ierr = SNESDestroy(&user->snes);CHKERRQ(ierr);
ierr = DMDestroy(&user->dm);CHKERRQ(ierr);
} else {
SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"WRONG option for the time integral method. Using the option '-time_integral_method 0 or 1'");
}
ierr = VecDestroy(&user->cellgeom);CHKERRQ(ierr);
ierr = VecDestroy(&user->facegeom);CHKERRQ(ierr);
ierr = DMDestroy(&user->dmGrad);CHKERRQ(ierr);
ierr = PetscFunctionListDestroy(&LimitList);CHKERRQ(ierr);
ierr = PetscFree(user->model->physics);CHKERRQ(ierr);
ierr = PetscFree(user->algebra);CHKERRQ(ierr);
ierr = PetscFree(user->model);CHKERRQ(ierr);
ierr = PetscFree(user);CHKERRQ(ierr);
{
PetscLogDouble space =0;
ierr = PetscMallocGetCurrentUsage(&space);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Unfreed space at the End %g M\n", space/(1024*1024));CHKERRQ(ierr);
}
ierr = PetscFinalize();
return(0);
}