LBPM/models/ColorModel.cpp

/*
color lattice boltzmann model
 */
#include "models/ColorModel.h"

ScaLBL_ColorModel::ScaLBL_ColorModel(int RANK, int NP, MPI_Comm COMM):
rank(RANK), nprocs(NP), Restart(0),timestep(0),timestepMax(0),tauA(0),tauB(0),rhoA(0),rhoB(0),alpha(0),beta(0),
Fx(0),Fy(0),Fz(0),flux(0),din(0),dout(0),inletA(0),inletB(0),outletA(0),outletB(0),
Nx(0),Ny(0),Nz(0),N(0),Np(0),nprocx(0),nprocy(0),nprocz(0),BoundaryCondition(0),Lx(0),Ly(0),Lz(0),comm(COMM)
{

}
ScaLBL_ColorModel::~ScaLBL_ColorModel(){

}

void ScaLBL_ColorModel::ReadParams(string filename){
	// read the input database 
	db = std::make_shared<Database>( filename );
	domain_db = db->getDatabase( "Domain" );
	color_db = db->getDatabase( "Color" );
	analysis_db = db->getDatabase( "Analysis" );

	// Color Model parameters
	timestepMax = color_db->getScalar<int>( "timestepMax" );
	tauA = color_db->getScalar<double>( "tauA" );
	tauB = color_db->getScalar<double>( "tauB" );
	rhoA = color_db->getScalar<double>( "rhoA" );
	rhoB = color_db->getScalar<double>( "rhoB" );
	Fx = color_db->getVector<double>( "F" )[0];
	Fy = color_db->getVector<double>( "F" )[1];
	Fz = color_db->getVector<double>( "F" )[2];
	alpha = color_db->getScalar<double>( "alpha" );
	beta = color_db->getScalar<double>( "beta" );
	Restart = color_db->getScalar<bool>( "Restart" );
	din = color_db->getScalar<double>( "din" );
	dout = color_db->getScalar<double>( "dout" );
	flux = color_db->getScalar<double>( "flux" );
	inletA=1.f;
	inletB=0.f;
	outletA=0.f;
	outletB=1.f;
	
	if (BoundaryCondition==4) flux = din*rhoA; // mass flux must adjust for density (see formulation for details)

	// Read domain parameters
	auto L = domain_db->getVector<double>( "L" );
	auto size = domain_db->getVector<int>( "n" );
	auto nproc = domain_db->getVector<int>( "nproc" );
	BoundaryCondition = domain_db->getScalar<int>( "BC" );
	Nx = size[0];
	Ny = size[1];
	Nz = size[2];
	Lx = L[0];
	Ly = L[1];
	Lz = L[2];
	nprocx = nproc[0];
	nprocy = nproc[1];
	nprocz = nproc[2];

}
void ScaLBL_ColorModel::SetDomain(){
	Dm  = std::shared_ptr<Domain>(new Domain(domain_db,comm));      // full domain for analysis
	Mask  = std::shared_ptr<Domain>(new Domain(domain_db,comm));    // mask domain removes immobile phases
	Nx+=2; Ny+=2; Nz += 2;
	N = Nx*Ny*Nz;
	for (int i=0; i<Nx*Ny*Nz; i++) Dm->id[i] = 1;               // initialize this way
	Averages = std::shared_ptr<TwoPhase> ( new TwoPhase(Dm) ); // TwoPhase analysis object
	MPI_Barrier(comm);
	Dm->CommInit();
	MPI_Barrier(comm);
}

void ScaLBL_ColorModel::ReadInput(){
    int rank=Dm->rank();
    size_t readID;
    //.......................................................................
    if (rank == 0)    printf("Read input media... \n");
    //.......................................................................
    Mask->ReadIDs();
    
    sprintf(LocalRankString,"%05d",Dm->rank());
    sprintf(LocalRankFilename,"%s%s","ID.",LocalRankString);
    sprintf(LocalRestartFile,"%s%s","Restart.",LocalRankString);

    // .......... READ THE INPUT FILE .......................................
    //...........................................................................
    if (rank == 0) cout << "Reading in signed distance function..." << endl;
    //.......................................................................
    sprintf(LocalRankString,"%05d",rank);
    sprintf(LocalRankFilename,"%s%s","SignDist.",LocalRankString);
    ReadBinaryFile(LocalRankFilename, Averages->SDs.data(), N);
    MPI_Barrier(comm);
    if (rank == 0) cout << "Domain set." << endl;

    // Read restart file
     if (Restart == true){
       if (Dm->rank()==0){
    	    size_t readID;
             printf("Reading restart file! \n");
             ifstream restart("Restart.txt");
             if (restart.is_open()){
                 restart  >> timestep;
                 printf("Restarting from timestep =%i \n",timestep);
             }
             else{
                 printf("WARNING:No Restart.txt file, setting timestep=0 \n");
                 timestep=0;
             }
         }
         MPI_Bcast(&timestep,1,MPI_INT,0,comm);
         FILE *RESTART = fopen(LocalRestartFile,"rb");
         if (RESTART==NULL) ERROR("lbpm_color_simulator: Error opening file: Restart.xxxxx");
         readID=fread(id,1,N,RESTART);
         if (readID != size_t(N)) printf("lbpm_color_simulator: Error reading Restart (rank=%i) \n",rank);
         fclose(RESTART);

         MPI_Barrier(comm);
     }
}
void ScaLBL_ColorModel::AssignComponentLabels(double *phase)
{
  int rank=Dm->rank();
	int NLABELS=0;
	char VALUE=0;
	double AFFINITY=0.f;
	
	vector <char> Label;
	vector <double> Affinity;
	// Read the labels
	if (rank==0){
		printf("Component labels:\n");
		ifstream iFILE("ComponentLabels.csv");
		if (iFILE.good()){
			int value;
			while (!iFILE.eof()){
				iFILE>>value;
				iFILE>>AFFINITY;
				VALUE=char(value);
				Label.push_back(value);
				Affinity.push_back(AFFINITY);
				NLABELS++;
				printf("%i %f\n",VALUE,AFFINITY);
			}
		}
		else{
			printf("Using default labels: Solid (0 --> -1.0), NWP (1 --> 1.0), WP (2 --> -1.0)\n");
			// Set default values
			VALUE=0; AFFINITY=-1.0;
			Label.push_back(VALUE);
			Affinity.push_back(AFFINITY);
			NLABELS++;
			VALUE=1; AFFINITY=1.0;
			Label.push_back(VALUE);
			Affinity.push_back(AFFINITY);
			NLABELS++;
			VALUE=2; AFFINITY=-1.0;
			Label.push_back(VALUE);
			Affinity.push_back(AFFINITY);
			NLABELS++;
		}
	}
	MPI_Barrier(comm);

	// Broadcast the list
	MPI_Bcast(&NLABELS,1,MPI_INT,0,comm);
	//printf("rank=%i, NLABELS=%i \n ",rank(),NLABELS);
	
	// Copy into contiguous buffers
	char *LabelList;
	double * AffinityList;
	LabelList=new char[NLABELS];
	AffinityList=new double[NLABELS];

	if (rank==0){
	for (int idx=0; idx < NLABELS; idx++){
		VALUE=Label[idx];
		AFFINITY=Affinity[idx];
		printf("rank=%i, idx=%i, value=%d, affinity=%f \n",rank,idx,VALUE,AFFINITY);
		LabelList[idx]=VALUE;
		AffinityList[idx]=AFFINITY;
	} 
	}
	MPI_Barrier(comm);

	MPI_Bcast(LabelList,NLABELS,MPI_CHAR,0,comm);
	MPI_Bcast(AffinityList,NLABELS,MPI_DOUBLE,0,comm);
	
	// Assign the labels
	for (int k=0;k<Nz;k++){
		for (int j=0;j<Ny;j++){
			for (int i=0;i<Nx;i++){
				int n = k*Nx*Ny+j*Nx+i;
				VALUE=Mask->id[n];
				// Assign the affinity from the paired list
				for (int idx=0; idx < NLABELS; idx++){
					//printf("rank=%i, idx=%i, value=%i, %i, \n",rank(),idx, VALUE,LabelList[idx]);
					if (VALUE == LabelList[idx]){
						AFFINITY=AffinityList[idx];
						idx = NLABELS;
					}
				}
				phase[n] = AFFINITY;
			}
		}
	}
}


void ScaLBL_ColorModel::Create(){
	/*
	 *  This function creates the variables needed to run a LBM 
	 */
	int rank=Dm->rank();
	//.........................................................
	// don't perform computations at the eight corners
	//id[0] = id[Nx-1] = id[(Ny-1)*Nx] = id[(Ny-1)*Nx + Nx-1] = 0;
	//id[(Nz-1)*Nx*Ny] = id[(Nz-1)*Nx*Ny+Nx-1] = id[(Nz-1)*Nx*Ny+(Ny-1)*Nx] = id[(Nz-1)*Nx*Ny+(Ny-1)*Nx + Nx-1] = 0;
	
	//.........................................................
	// Initialize communication structures in averaging domain
	for (int i=0; i<Nx*Ny*Nz; i++) Dm->id[i] = Mask->id[i];
	Mask->CommInit();
	Np=Mask->PoreCount();
	//...........................................................................
	if (rank==0)    printf ("Create ScaLBL_Communicator \n");
	// Create a communicator for the device (will use optimized layout)
	// ScaLBL_Communicator ScaLBL_Comm(Mask); // original
	ScaLBL_Comm  = std::shared_ptr<ScaLBL_Communicator>(new ScaLBL_Communicator(Mask));

	int Npad=(Np/16 + 2)*16;
	if (rank==0)    printf ("Set up memory efficient layout \n");
	Map.resize(Nx,Ny,Nz);       Map.fill(-2);
	auto neighborList= new int[18*Npad];
	Np = ScaLBL_Comm->MemoryOptimizedLayoutAA(Map,neighborList,Mask->id,Np);
	MPI_Barrier(comm);

	//...........................................................................
	//                MAIN  VARIABLES ALLOCATED HERE
	//...........................................................................
	// LBM variables
	if (rank==0)    printf ("Allocating distributions \n");
	//......................device distributions.................................
	int dist_mem_size = Np*sizeof(double);
	int neighborSize=18*(Np*sizeof(int));

	//...........................................................................
	ScaLBL_AllocateDeviceMemory((void **) &NeighborList, neighborSize);
	ScaLBL_AllocateDeviceMemory((void **) &dvcMap, sizeof(int)*Np);
	ScaLBL_AllocateDeviceMemory((void **) &fq, 19*dist_mem_size);
	ScaLBL_AllocateDeviceMemory((void **) &Aq, 7*dist_mem_size);
	ScaLBL_AllocateDeviceMemory((void **) &Bq, 7*dist_mem_size);
	ScaLBL_AllocateDeviceMemory((void **) &Den, 2*dist_mem_size);
	ScaLBL_AllocateDeviceMemory((void **) &Phi, sizeof(double)*Np);        
	ScaLBL_AllocateDeviceMemory((void **) &Pressure, sizeof(double)*Np);
	ScaLBL_AllocateDeviceMemory((void **) &Velocity, 3*sizeof(double)*Np);
	ScaLBL_AllocateDeviceMemory((void **) &Gradient, 3*sizeof(double)*Np);
	ScaLBL_AllocateDeviceMemory((void **) &SolidPotential, 3*sizeof(double)*Np);

	//...........................................................................
	// Update GPU data structures
	if (rank==0)    printf ("Setting up device map and neighbor list \n");
	// copy the neighbor list 
	ScaLBL_CopyToDevice(NeighborList, neighborList, neighborSize);

	int *TmpMap;
	TmpMap=new int[Np];
	for (int k=1; k<Nz-1; k++){
		for (int j=1; j<Ny-1; j++){
			for (int i=1; i<Nx-1; i++){
				int idx=Map(i,j,k);
				if (!(idx < 0))
					TmpMap[idx] = k*Nx*Ny+j*Nx+i;
			}
		}
	}
	ScaLBL_CopyToDevice(dvcMap, TmpMap, sizeof(int)*Np);
	ScaLBL_DeviceBarrier();
	delete [] TmpMap;
}        

/********************************************************
 * AssignComponentLabels                                 *
 ********************************************************/
void ScaLBL_ColorModel::AssignSolidPotential(){
	if (rank==0) printf("Computing solid interaction potential \n");
	double *PhaseLabel;
	PhaseLabel=new double [Nx*Ny*Nz];
	AssignComponentLabels(PhaseLabel);
	double *Tmp;
	Tmp=new double[3*Np];
	//Averages->UpdateMeshValues(); // this computes the gradient of distance field (among other things)
	// Create the distance stencil
	// Compute solid forces based on mean field approximation
	double *Dst;
	Dst = new double [5*5*5];
	for (int kk=0; kk<5; kk++){
		for (int jj=0; jj<5; jj++){
			for (int ii=0; ii<5; ii++){
				int index = kk*25+jj*5+ii;
				Dst[index] = sqrt(double(ii-2)*double(ii-2) + double(jj-2)*double(jj-2)+ double(kk-2)*double(kk-2));
			}
		}
	}
	for (int k=1; k<Nz-1; k++){
		for (int j=1; j<Ny-1; j++){
			for (int i=1; i<Nx-1; i++){
				int idx=Map(i,j,k);
				if (!(idx < 0)){

					double phi_x = 0.f;
					double phi_y = 0.f;
					double phi_z = 0.f;
					for (int kk=0; kk<5; kk++){
						for (int jj=0; jj<5; jj++){
							for (int ii=0; ii<5; ii++){

								int index = kk*25+jj*5+ii;
								double distval= Dst[index];

								int idi=i+ii-2;
								int idj=j+jj-2;
								int idk=k+kk-2;

								if (idi < 0) idi=0;
								if (idj < 0) idj=0;
								if (idk < 0) idk=0;
								if (!(idi < Nx)) idi=Nx-1;
								if (!(idj < Ny)) idj=Ny-1;
								if (!(idk < Nz)) idk=Nz-1;

								int nn = idk*Nx*Ny + idj*Nx + idi;
								if (!(Mask->id[nn] > 0)){
									double vec_x = double(ii-2);
									double vec_y = double(jj-2);
									double vec_z = double(kk-2);

									double ALPHA=PhaseLabel[nn];
									double GAMMA=-2.f;
									if (distval > 2.f) ALPHA=0.f; // symmetric cutoff distance                                    
									phi_x += ALPHA*exp(GAMMA*distval)*vec_x/distval;
									phi_y += ALPHA*exp(GAMMA*distval)*vec_y/distval;
									phi_z += ALPHA*exp(GAMMA*distval)*vec_z/distval;
								}
							}
						}
					}
					Tmp[idx] = phi_x;
					Tmp[idx+Np] = phi_y;
					Tmp[idx+2*Np] = phi_z;

					/*                        double d = Averages->SDs(n);
                                         double dx = Averages->SDs_x(n);
                                         double dy = Averages->SDs_y(n);
                                         double dz = Averages->SDs_z(n);
                                         double value=cns*exp(-bns*fabs(d))-cws*exp(-bns*fabs(d));

                 Tmp[idx] = value*dx;
                 Tmp[idx+Np] = value*dy;
                 Tmp[idx+2*Np] = value*dz;
					 */
				}
			}
		}
	}
	ScaLBL_CopyToDevice(SolidPotential, Tmp, 3*sizeof(double)*Np);
	ScaLBL_DeviceBarrier();
	delete [] Tmp;
	delete [] Dst;

	DoubleArray Psx(Nx,Ny,Nz);
	DoubleArray Psy(Nx,Ny,Nz);
	DoubleArray Psz(Nx,Ny,Nz);
	DoubleArray Psnorm(Nx,Ny,Nz);
	ScaLBL_Comm->RegularLayout(Map,&SolidPotential[0],Psx);
	ScaLBL_Comm->RegularLayout(Map,&SolidPotential[Np],Psy);
	ScaLBL_Comm->RegularLayout(Map,&SolidPotential[2*Np],Psz);
	for (int n=0; n<N; n++) Psnorm(n) = Psx(n)*Psx(n)+Psy(n)*Psy(n)+Psz(n)*Psz(n);
	FILE *PFILE;
	sprintf(LocalRankFilename,"Potential.%05i.raw",rank);
	PFILE = fopen(LocalRankFilename,"wb");
	fwrite(Psnorm.data(),8,N,PFILE);
	fclose(PFILE);
}
void ScaLBL_ColorModel::Initialize(){
	/*
	 * This function initializes model
	 */
	int rank=Dm->rank();
	double count_wet=0.f;
	double *PhaseLabel;
	PhaseLabel=new double [Nx*Ny*Nz];
	for (int k=1; k<Nz-1; k++){
		for (int j=1; j<Ny-1; j++){
			for (int i=1; i<Nx-1; i++){
				int idx=Map(i,j,k);
				int n = k*Nx*Ny+j*Nx+i;
				if (!(idx < 0)){
					if (Mask->id[n] == 1)
						PhaseLabel[idx] = 1.0;
					else {
						PhaseLabel[idx] = -1.0;
						count_wet+=1.f;
					}
				}
			}
		}
	}
	//printf("sw=%f \n",count_wet/double(Np));
	// initialize phi based on PhaseLabel (include solid component labels)
	ScaLBL_CopyToDevice(Phi, PhaseLabel, Np*sizeof(double));
	//...........................................................................

	if (rank==0)    printf ("Initializing distributions \n");
	ScaLBL_D3Q19_Init(fq, Np);
	if (rank==0)    printf ("Initializing phase field \n");
	ScaLBL_DFH_Init(Phi, Den, Aq, Bq, 0, ScaLBL_Comm->LastExterior(), Np);
	ScaLBL_DFH_Init(Phi, Den, Aq, Bq, ScaLBL_Comm->FirstInterior(), ScaLBL_Comm->LastInterior(), Np);

}

void ScaLBL_ColorModel::Run(){
    int nprocs=nprocx*nprocy*nprocz;
    int rank=Dm->rank();
    const RankInfoStruct rank_info(rank,nprocx,nprocy,nprocz);

    if (rank==0) printf("********************************************************\n");
    if (rank==0)    printf("No. of timesteps: %i \n", timestepMax);
    //.......create and start timer............
    double starttime,stoptime,cputime;
    ScaLBL_DeviceBarrier();
    MPI_Barrier(comm);
    starttime = MPI_Wtime();
    //.........................................
    //************ MAIN ITERATION LOOP ***************************************/

    PROFILE_START("Loop");
    runAnalysis analysis( analysis_db, rank_info, ScaLBL_Comm, Dm, Np, pBC, beta, Map );
    while (timestep < timestepMax ) {
        //if ( rank==0 ) { printf("Running timestep %i (%i MB)\n",timestep+1,(int)(Utilities::getMemoryUsage()/1048576)); }
        PROFILE_START("Update");
        // *************ODD TIMESTEP*************
        timestep++;
        // Compute the Phase indicator field
        // Read for Aq, Bq happens in this routine (requires communication)
        ScaLBL_Comm->BiSendD3Q7AA(Aq,Bq); //READ FROM NORMAL
        ScaLBL_D3Q7_AAodd_DFH(NeighborList, Aq, Bq, Den, Phi, ScaLBL_Comm->first_interior, ScaLBL_Comm->last_interior, Np);
        ScaLBL_Comm->BiRecvD3Q7AA(Aq,Bq); //WRITE INTO OPPOSITE
        ScaLBL_D3Q7_AAodd_DFH(NeighborList, Aq, Bq, Den, Phi, 0, ScaLBL_Comm->next, Np);
        
        // compute the gradient 
        ScaLBL_D3Q19_Gradient_DFH(NeighborList, Phi, Gradient, SolidPotential, ScaLBL_Comm->first_interior, ScaLBL_Comm->last_interior, Np);
        ScaLBL_Comm->SendHalo(Phi);
        ScaLBL_D3Q19_Gradient_DFH(NeighborList, Phi, Gradient, SolidPotential, 0, ScaLBL_Comm->next, Np);
        ScaLBL_Comm->RecvGrad(Phi,Gradient);
        
        // Perform the collision operation
        ScaLBL_Comm->SendD3Q19AA(fq); //READ FROM NORMAL
        ScaLBL_D3Q19_AAodd_DFH(NeighborList, fq, Aq, Bq, Den, Phi, Gradient, rhoA, rhoB, tauA, tauB,
                alpha, beta, Fx, Fy, Fz, ScaLBL_Comm->first_interior, ScaLBL_Comm->last_interior, Np);
        ScaLBL_Comm->RecvD3Q19AA(fq); //WRITE INTO OPPOSITE
        // Set BCs
        if (BoundaryCondition > 0){
            ScaLBL_Comm->Color_BC_z(dvcMap, Phi, Den, inletA, inletB);
            ScaLBL_Comm->Color_BC_Z(dvcMap, Phi, Den, outletA, outletB);
        }
        if (BoundaryCondition == 3){
            ScaLBL_Comm->D3Q19_Pressure_BC_z(NeighborList, fq, din, timestep);
            ScaLBL_Comm->D3Q19_Pressure_BC_Z(NeighborList, fq, dout, timestep);
        }
        if (BoundaryCondition == 4){
            din = ScaLBL_Comm->D3Q19_Flux_BC_z(NeighborList, fq, flux, timestep);
            ScaLBL_Comm->D3Q19_Pressure_BC_Z(NeighborList, fq, dout, timestep);
        }
        ScaLBL_D3Q19_AAodd_DFH(NeighborList, fq, Aq, Bq, Den, Phi, Gradient, rhoA, rhoB, tauA, tauB,
                alpha, beta, Fx, Fy, Fz, 0, ScaLBL_Comm->next, Np);
        ScaLBL_DeviceBarrier(); MPI_Barrier(comm);

        // *************EVEN TIMESTEP*************
        timestep++;
        // Compute the Phase indicator field
        ScaLBL_Comm->BiSendD3Q7AA(Aq,Bq); //READ FROM NORMAL
        ScaLBL_D3Q7_AAeven_DFH(Aq, Bq, Den, Phi, ScaLBL_Comm->first_interior, ScaLBL_Comm->last_interior, Np);
        ScaLBL_Comm->BiRecvD3Q7AA(Aq,Bq); //WRITE INTO OPPOSITE
        ScaLBL_D3Q7_AAeven_DFH(Aq, Bq, Den, Phi, 0, ScaLBL_Comm->next, Np);
        
        // compute the gradient 
        ScaLBL_D3Q19_Gradient_DFH(NeighborList, Phi, Gradient, SolidPotential, ScaLBL_Comm->first_interior, ScaLBL_Comm->last_interior, Np);
        ScaLBL_Comm->SendHalo(Phi);
        ScaLBL_D3Q19_Gradient_DFH(NeighborList, Phi, Gradient, SolidPotential, 0, ScaLBL_Comm->next, Np);
        ScaLBL_Comm->RecvGrad(Phi,Gradient);

        // Perform the collision operation
        ScaLBL_Comm->SendD3Q19AA(fq); //READ FORM NORMAL
        ScaLBL_D3Q19_AAeven_DFH(NeighborList, fq, Aq, Bq, Den, Phi, Gradient, rhoA, rhoB, tauA, tauB,
                alpha, beta, Fx, Fy, Fz, ScaLBL_Comm->first_interior, ScaLBL_Comm->last_interior, Np);
        ScaLBL_Comm->RecvD3Q19AA(fq); //WRITE INTO OPPOSITE
        // Set boundary conditions
        if (BoundaryCondition > 0){
            ScaLBL_Comm->Color_BC_z(dvcMap, Phi, Den, inletA, inletB);
            ScaLBL_Comm->Color_BC_Z(dvcMap, Phi, Den, outletA, outletB);
        }
        if (BoundaryCondition == 3){
            ScaLBL_Comm->D3Q19_Pressure_BC_z(NeighborList, fq, din, timestep);
            ScaLBL_Comm->D3Q19_Pressure_BC_Z(NeighborList, fq, dout, timestep);
        }
        else if (BoundaryCondition == 4){
            din = ScaLBL_Comm->D3Q19_Flux_BC_z(NeighborList, fq, flux, timestep);
            ScaLBL_Comm->D3Q19_Pressure_BC_Z(NeighborList, fq, dout, timestep);
        }
        ScaLBL_D3Q19_AAeven_DFH(NeighborList, fq, Aq, Bq, Den, Phi, Gradient, rhoA, rhoB, tauA, tauB,
                alpha, beta, Fx, Fy, Fz,  0, ScaLBL_Comm->next, Np);
        ScaLBL_DeviceBarrier(); MPI_Barrier(comm);
        //************************************************************************
        MPI_Barrier(comm);
        PROFILE_STOP("Update");

        // Run the analysis
	analysis.run( timestep, *Averages, Phi, Pressure, Velocity, fq, Den );
    }
    analysis.finish();
    PROFILE_STOP("Loop");
    PROFILE_SAVE("lbpm_color_simulator",1);
    //************************************************************************
    ScaLBL_DeviceBarrier();
    MPI_Barrier(comm);
    stoptime = MPI_Wtime();
    if (rank==0) printf("-------------------------------------------------------------------\n");
    // Compute the walltime per timestep
    cputime = (stoptime - starttime)/timestep;
    // Performance obtained from each node
    double MLUPS = double(Np)/cputime/1000000;
    if (rank==0) printf("********************************************************\n");
    if (rank==0) printf("CPU time = %f \n", cputime);
    if (rank==0) printf("Lattice update rate (per core)= %f MLUPS \n", MLUPS);
    MLUPS *= nprocs;
    if (rank==0) printf("Lattice update rate (total)= %f MLUPS \n", MLUPS);
    if (rank==0) printf("********************************************************\n");

    // ************************************************************************
}

void ScaLBL_ColorModel::WriteDebug(){
	// Copy back final phase indicator field and convert to regular layout
	DoubleArray PhaseField(Nx,Ny,Nz);
	ScaLBL_Comm->RegularLayout(Map,Phi,PhaseField);
	FILE *OUTFILE;
	sprintf(LocalRankFilename,"Phase.%05i.raw",rank);
	OUTFILE = fopen(LocalRankFilename,"wb");
	fwrite(PhaseField.data(),8,N,OUTFILE);
	fclose(OUTFILE);
}