Problem in running showcase 'externalFlowAroundObstacle' using Code::Blocks

I am new user for Palabos and I was using Code::Blocks for running the palabos coding of ‘externalFlowAroundObstacle’. However, I do not manage to compile and run it. It shows the error as below:

‘Wrong parameter; the syntax is: C:\Users\DELL\Dekstop\EMD 452 FYP\palabos\palabos-v1.4r0\codeblocks\bin\Release\Palabos.exe input-file.xml
Process returned -1 <0xFFFFFFFF> execution time : 0.010s
Press any key to continue.’

Do anyone know what is the problem?? Or some advise to help me on compiling and running this showcase using Code::Blocks.
Any helpful advise I would appreciate it…

Have you given the program any argument? It takes the xml as argument.

Actually I was running the showcase (externalFlowAroundObstacle) from palabos-v1.4r1. I not actually understand the code. I just compile the code given and it failed (showing the error above). Below is part of the code that I suspicious the cause of the problem. Am I need to change the xml name?? or it is due to problem of argument??

string xmlFname;
try {
catch (PlbIOException& exception) {
pcout << “Wrong parameters; the syntax is: "
<< (std::string)global::argv(0) << " input-file.xml” << std::endl;
return -1;

// 2. Read input parameters from the XML file.
try {
    param = Param(xmlFname);
catch (PlbIOException& exception) {
    pcout << exception.what() << std::endl;
    return -1;

// 3. Execute the main program.
try {
catch (PlbIOException& exception) {
    pcout << exception.what() << std::endl;
    return -1;


I think I faced this problem the first. What was wrong for me was that the program takes an argument so you must provide it. If you use codeblocks you can give by the GUI or if you launch in the command line you give it next to the work of the executable. If this is elementary and you are doing it, excuse me for that, if you are not doing it I can give you more details if you didn’t understand me.


i have the same probleme when i try to run the example of “externalFlowArounObstacle”, it chows me this message
““Wrong parameters; the syntax is: ./externalFlowAroundObstacle input-file.xml””
please can you give me more details

I am sry that I am a new user. So, I actually quite not understand what the purpose and how to use the argument. May I ask how can I provide argument at above case if i am using codeblocks bt not command line. May u give me more detail. (I didn’t done any editing to the code after I download form palabos website).

I am very sorry for being so late, I am attaching some snapshot of how to do it in CodeBlocks
In program arguments must be the dir of your xml file

PD: If you are working in sth related with this example I would like to keep in touch with you, so please send me a PM

Why I cannot access your image. May you reupload the image or other link??
Ya, I assign to do 3D external flow through an obstacle simulation. Below is the coding from palabos , which part do you think i have to change?? Inside the showcase external flow through obstacle got 3 file (xml file name externalFlowAroundObstacle, stl file name obstacle and makefile)

#include “palabos3D.h”
#include “palabos3D.hh”

using namespace plb;
using namespace std;

typedef double T;
typedef Array<T,3> Velocity;
#define DESCRIPTOR descriptors::D3Q19Descriptor

#define PADDING 8

static std::string outputDir("./tmp/");

// This structure holds all the user-defined parameters, and some
// derived values needed for the simulation.
struct Param
T nu; // Kinematic viscosity.
T lx, ly, lz; // Size of computational domain, in physical units.
T cx, cy, cz; // Position of the center of the obstacle, in physical units.
plint cxLB, cyLB, czLB; // Position of the center of the obstacle, in lattice units.
bool freeSlipWall; // Use free-slip condition on obstacle, as opposed to no-slip?
bool lateralFreeSlip; // Use free-slip lateral boundaries or periodic ones?
T maxT, statT, imageT, vtkT; // Time, in physical units, at which events occur.
plint resolution; // Number of lattice nodes along a reference length.
T inletVelocity; // Inlet x-velocity in physical units.
T uLB; // Velocity in lattice units (numerical parameters).
bool useSmago; // Use a Smagorinsky LES model or not.
T cSmago; // Parameter for the Smagorinsky LES model.
plint nx, ny, nz; // Grid resolution of bounding box.
T omega; // Relaxation parameter.
T dx, dt; // Discrete space and time steps.
plint maxIter, statIter; // Time for events in lattice units.
plint imageIter, vtkIter;
bool useParticles; // Simulate particles or not.
int particleTimeFactor; // If the particle time factor is 2, then the integration time step
// for the particles is twice that of the fluid.
T particleProbabilityPerCell; // Probability of injection of a particle at an injection cell at each time step.
T cutOffSpeedSqr; // Criterion to eliminate particles with very small velocity.
int maxNumParticlesToWrite; // Maximum number of particles in the output VTK files.

T outletSpongeZoneWidth;            // Width of the outlet sponge zone.
plint numOutletSpongeCells;         // Number of the lattice nodes contained in the outlet sponge zone.
int outletSpongeZoneType;           // Type of the outlet sponge zone (Viscosity or Smagorinsky).
T targetSpongeCSmago;               // Target Smagorinsky parameter at the end of the Smagorinsky sponge Zone.
plint initialIter;                  // Number of initial iterations until the inlet velocity reaches its final value.

Box3D inlet, outlet, lateral1;      // Outer domain boundaries in lattice units.
Box3D lateral2, lateral3, lateral4;

std::string geometry_fname;

{ }

Param(std::string xmlFname)
    XMLreader document(xmlFname);

    if (useSmago) {

    if (useParticles) {

    std::string zoneType;
    if ((util::tolower(zoneType)).compare("viscosity") == 0) {
        outletSpongeZoneType = 0;
    } else if ((util::tolower(zoneType)).compare("smagorinsky") == 0) {
        outletSpongeZoneType = 1;
    } else {
        pcout << "The sponge zone type must be either \"Viscosity\" or \"Smagorinsky\"." << std::endl;




void computeLBparameters()
    dx = ly / (resolution - 1.0);
    dt = (uLB/inletVelocity) * dx;
    T nuLB = nu * dt/(dx*dx);
    omega = 1.0/(3.0*nuLB+0.5);
    nx = util::roundToInt(lx/dx);
    ny = util::roundToInt(ly/dx);
    nz = util::roundToInt(lz/dx);
    cxLB = util::roundToInt(cx/dx);
    cyLB = util::roundToInt(cy/dx);
    czLB = util::roundToInt(cz/dx);
    maxIter   = util::roundToInt(maxT/dt);
    statIter  = util::roundToInt(statT/dt);
    imageIter = util::roundToInt(imageT/dt);
    vtkIter   = util::roundToInt(vtkT/dt);
    numOutletSpongeCells = util::roundToInt(outletSpongeZoneWidth/dx);

    inlet    = Box3D(0,      0,      0,      ny-1,   0,      nz-1);
    outlet   = Box3D(nx-1,   nx-1,   0,      ny-1,   0,      nz-1);
    lateral1 = Box3D(1,      nx-2,   0,      0,      0,      nz-1);
    lateral2 = Box3D(1,      nx-2,   ny-1,   ny-1,   0,      nz-1);
    lateral3 = Box3D(1,      nx-2,   1,      ny-2,   0,      0);
    lateral4 = Box3D(1,      nx-2,   1,      ny-2,   nz-1,   nz-1);

Box3D boundingBox() const
    return Box3D(0, nx-1, 0, ny-1, 0, nz-1);

T getInletVelocity(plint iIter)
    static T pi = acos(-1.0);

    if (iIter >= initialIter) {
        return uLB;

    if (iIter < 0) {
        iIter = 0;

    return uLB * sin(pi * iIter / (2.0 * initialIter));


Param param;

// Instantiate the boundary conditions for the outer domain.
void outerDomainBoundaries(MultiBlockLattice3D<T,DESCRIPTOR> *lattice,
MultiScalarField3D *rhoBar,
MultiTensorField3D<T,3> *j,
OnLatticeBoundaryCondition3D<T,DESCRIPTOR> *bc)
Array<T,3> uBoundary(param.getInletVelocity(0), 0.0, 0.0);

if (param.lateralFreeSlip) {
    pcout << "Free-slip lateral boundaries." << std::endl;


    bc->setVelocityConditionOnBlockBoundaries(*lattice, param.inlet, boundary::dirichlet);
    setBoundaryVelocity(*lattice, param.inlet, uBoundary);

    bc->setVelocityConditionOnBlockBoundaries(*lattice, param.lateral1, boundary::freeslip);
    bc->setVelocityConditionOnBlockBoundaries(*lattice, param.lateral2, boundary::freeslip);
    bc->setVelocityConditionOnBlockBoundaries(*lattice, param.lateral3, boundary::freeslip);
    bc->setVelocityConditionOnBlockBoundaries(*lattice, param.lateral4, boundary::freeslip);

    // The VirtualOutlet is a sophisticated outflow boundary condition.
    Box3D globalDomain(lattice->getBoundingBox());
    std::vector<MultiBlock3D*> bcargs;
    T outsideDensity = 1.0;
    int bcType = 1;
    integrateProcessingFunctional(new VirtualOutlet<T,DESCRIPTOR>(outsideDensity, globalDomain, bcType),
            param.outlet, bcargs, 2);
} else {
    pcout << "Periodic lateral boundaries." << std::endl;


    lattice->periodicity().toggle(0, false);
    rhoBar->periodicity().toggle(0, false);
    j->periodicity().toggle(0, false);

    bc->addVelocityBoundary0N(param.inlet, *lattice);
    setBoundaryVelocity(*lattice, param.inlet, uBoundary);

    // The VirtualOutlet is a sophisticated outflow boundary condition.
    // The "globalDomain" argument for the boundary condition must be
    // bigger than the actual bounding box of the simulation for
    // the directions which are periodic.
    Box3D globalDomain(lattice->getBoundingBox());
    globalDomain.y0 -= 2; // y-periodicity
    globalDomain.y1 += 2;
    globalDomain.z0 -= 2; // z-periodicity
    globalDomain.z1 += 2;
    std::vector<MultiBlock3D*> bcargs;
    T outsideDensity = 1.0;
    int bcType = 1;
    integrateProcessingFunctional(new VirtualOutlet<T,DESCRIPTOR>(outsideDensity, globalDomain, bcType),
            param.outlet, bcargs, 2);


// Write VTK file for the flow around the obstacle, to be viewed with Paraview.
void writeVTK(OffLatticeBoundaryCondition3D<T,DESCRIPTOR,Velocity>& bc, plint iT)
VtkImageOutput3D vtkOut(createFileName(“volume”, iT, PADDING));
vtkOut.writeData( *bc.computeVelocityNorm(param.boundingBox()),
“velocityNorm”, param.dx/param.dt );
vtkOut.writeData<3,float>(bc.computeVelocity(param.boundingBox()), “velocity”, param.dx/param.dt);
vtkOut.writeData( bc.computePressure(param.boundingBox()),
“pressure”, param.dx
param.dt) );

// Write PPM images on slices.
void writePPM(OffLatticeBoundaryCondition3D<T,DESCRIPTOR,Velocity>& bc, plint iT)
Box3D xSlice(param.cxLB, param.cxLB, 0, param.ny-1, 0,;
Box3D ySlice(0, param.nx-1, param.cyLB, param.cyLB, 0,;
Box3D zSlice(0, param.nx-1, 0, param.ny-1, param.czLB, param.czLB);

ImageWriter<T> writer("leeloo");
writer.writeScaledPpm(createFileName("vnorm_xslice", iT, PADDING), *bc.computeVelocityNorm(xSlice));
writer.writeScaledPpm(createFileName("vnorm_yslice", iT, PADDING), *bc.computeVelocityNorm(ySlice));
writer.writeScaledPpm(createFileName("vnorm_zslice", iT, PADDING), *bc.computeVelocityNorm(zSlice));


void runProgram()
* Read the obstacle geometry.

pcout << std::endl << "Reading STL data for the obstacle geometry." << std::endl;
Array<T,3> center(,,;
Array<T,3> centerLB(param.cxLB, param.cyLB, param.czLB);
// The triangle-set defines the surface of the geometry.
TriangleSet<T> triangleSet(param.geometry_fname, DBL);

// Place the obstacle in the correct place in the simulation domain.
// Here the "geometric center" of the obstacle is computed manually,
// by computing first its bounding cuboid. In cases that the STL
// file with the geometry of the obstacle contains its center as
// the point, say (0, 0, 0), then the following variable
// "obstacleCenter" must be set to (0, 0, 0) manually.
Cuboid<T> bCuboid = triangleSet.getBoundingCuboid();
Array<T,3> obstacleCenter = 0.5 * (bCuboid.lowerLeftCorner + bCuboid.upperRightCorner);
triangleSet.scale(1.0/param.dx); // In lattice units from now on...

// The DEFscaledMesh, and the triangle-boundary are more sophisticated data
// structures used internally by Palabos to treat the boundary.
plint xDirection = 0;
plint borderWidth = 1;      // Because Guo acts in a one-cell layer.
                            // Requirement: margin>=borderWidth.
plint margin = 1;           // Extra margin of allocated cells around the obstacle, for the case of moving walls.
plint blockSize = 0;        // Size of blocks in the sparse/parallel representation.
                            // Zero means: don't use sparse representation.
DEFscaledMesh<T> defMesh(triangleSet, 0, xDirection, margin, Dot3D(0, 0, 0));
TriangleBoundary3D<T> boundary(defMesh);

pcout << "tau = " << 1.0/ << std::endl;
pcout << "dx = " << param.dx << std::endl;
pcout << "dt = " << param.dt << std::endl;
pcout << "Number of iterations in an integral time scale: " << (plint) (1.0/param.dt) << std::endl;

 * Voxelize the domain.

// Voxelize the domain means: decide which lattice nodes are inside the obstacle and which are outside.
pcout << std::endl << "Voxelizing the domain." << std::endl;
plint extendedEnvelopeWidth = 2;   // Extrapolated off-lattice BCs.
const int flowType = voxelFlag::outside;
VoxelizedDomain3D<T> voxelizedDomain (
        boundary, flowType, param.boundingBox(), borderWidth, extendedEnvelopeWidth, blockSize );
pcout << getMultiBlockInfo(voxelizedDomain.getVoxelMatrix()) << std::endl;

 * Generate the lattice, the density and momentum blocks.

pcout << "Generating the lattice, the rhoBar and j fields." << std::endl;
MultiBlockLattice3D<T,DESCRIPTOR> *lattice = new MultiBlockLattice3D<T,DESCRIPTOR>(voxelizedDomain.getVoxelMatrix());
if (param.useSmago) {
    defineDynamics(*lattice, lattice->getBoundingBox(),
            new SmagorinskyBGKdynamics<T,DESCRIPTOR>(, param.cSmago));
    pcout << "Using Smagorinsky BGK dynamics." << std::endl;
} else {
    defineDynamics(*lattice, lattice->getBoundingBox(),
            new BGKdynamics<T,DESCRIPTOR>(;
    pcout << "Using BGK dynamics." << std::endl;
bool velIsJ = false;
defineDynamics(*lattice, voxelizedDomain.getVoxelMatrix(), lattice->getBoundingBox(),
        new NoDynamics<T,DESCRIPTOR>(), voxelFlag::inside);

MultiBlockManagement3D sparseBlockManagement(lattice->getMultiBlockManagement());

// The rhoBar and j fields are used at both the collision and at the implementation of the
// outflow boundary condition.
plint envelopeWidth = 1;
MultiScalarField3D<T> *rhoBar = new MultiScalarField3D<T> (
        MultiBlockManagement3D (
            envelopeWidth ),
        defaultMultiBlockPolicy3D().getMultiScalarAccess<T>() );

MultiTensorField3D<T,3> *j = new MultiTensorField3D<T,3> (
        MultiBlockManagement3D (
            envelopeWidth ),
        defaultMultiBlockPolicy3D().getMultiTensorAccess<T,3>() );

std::vector<MultiBlock3D*> lattice_rho_bar_j_arg;
        new ExternalRhoJcollideAndStream3D<T,DESCRIPTOR>(),
        lattice->getBoundingBox(), lattice_rho_bar_j_arg, 0);
        new BoxRhoBarJfunctional3D<T,DESCRIPTOR>(),
        lattice->getBoundingBox(), lattice_rho_bar_j_arg, 3); // rhoBar and j are computed at level 3 because
                                                              // the boundary conditions are on levels 1 and 2.

 * Generate the off-lattice boundary condition on the obstacle and the outer-domain boundary conditions.

pcout << "Generating boundary conditions." << std::endl;

OffLatticeBoundaryCondition3D<T,DESCRIPTOR,Velocity> *boundaryCondition;

BoundaryProfiles3D<T,Velocity> profiles;
bool useAllDirections=true;
OffLatticeModel3D<T,Velocity>* offLatticeModel=0;
if (param.freeSlipWall) {
    profiles.setWallProfile(new FreeSlipProfile3D<T>);
else {
    profiles.setWallProfile(new NoSlipProfile3D<T>);
offLatticeModel =
     new GuoOffLatticeModel3D<T,DESCRIPTOR> (
        new TriangleFlowShape3D<T,Array<T,3> >(voxelizedDomain.getBoundary(), profiles),
        flowType, useAllDirections );
boundaryCondition = new OffLatticeBoundaryCondition3D<T,DESCRIPTOR,Velocity>(
        offLatticeModel, voxelizedDomain, *lattice);


// The boundary condition algorithm or the outer domain.
OnLatticeBoundaryCondition3D<T,DESCRIPTOR>* outerBoundaryCondition
    = createLocalBoundaryCondition3D<T,DESCRIPTOR>();
outerDomainBoundaries(lattice, rhoBar, j, outerBoundaryCondition);

 * Implement the outlet sponge zone.

if (param.numOutletSpongeCells > 0) {
    T bulkValue;
    Array<plint,6> numSpongeCells;

    if (param.outletSpongeZoneType == 0) {
        pcout << "Generating an outlet viscosity sponge zone." << std::endl;
        bulkValue =;
    } else if (param.outletSpongeZoneType == 1) {
        pcout << "Generating an outlet Smagorinsky sponge zone." << std::endl;
        bulkValue = param.cSmago;
    } else {
        pcout << "Error: uknown type of sponge zone." << std::endl;

    // Number of sponge zone lattice nodes at all the outer domain boundaries.
    // So: 0 means the boundary at x = 0
    //     1 means the boundary at x = nx-1
    //     2 means the boundary at y = 0
    //     and so on...
    numSpongeCells[0] = 0;
    numSpongeCells[1] = param.numOutletSpongeCells;
    numSpongeCells[2] = 0;
    numSpongeCells[3] = 0;
    numSpongeCells[4] = 0;
    numSpongeCells[5] = 0;

    std::vector<MultiBlock3D*> args;

    if (param.outletSpongeZoneType == 0) {
        applyProcessingFunctional(new ViscositySpongeZone<T,DESCRIPTOR>(
                    param.nx, param.ny,, bulkValue, numSpongeCells),
                lattice->getBoundingBox(), args);
    } else {
        applyProcessingFunctional(new SmagorinskySpongeZone<T,DESCRIPTOR>(
                    param.nx, param.ny,, bulkValue, param.targetSpongeCSmago, numSpongeCells),
                lattice->getBoundingBox(), args);

 * Setting the initial conditions.

// Initial condition: Constant pressure and velocity-at-infinity everywhere.
Array<T,3> uBoundary(param.getInletVelocity(0), 0.0, 0.0);
initializeAtEquilibrium(*lattice, lattice->getBoundingBox(), 1.0, uBoundary);
lattice->executeInternalProcessors(1); // Execute all processors except the ones at level 0.

 * Particles (streamlines).

// This part of the code that relates to particles, is purely for visualization
// purposes. Particles are used to compute streamlines essentially.

// Definition of a particle field.
MultiParticleField3D<DenseParticleField3D<T,DESCRIPTOR> >* particles = 0;

if (param.useParticles) {
    particles = new MultiParticleField3D<DenseParticleField3D<T,DESCRIPTOR> > (
        defaultMultiBlockPolicy3D().getCombinedStatistics() );

    std::vector<MultiBlock3D*> particleArg;

    std::vector<MultiBlock3D*> particleFluidArg;

    // Functional that advances the particles to their new position at each predefined time step.
    integrateProcessingFunctional (
            new AdvanceParticlesEveryWhereFunctional3D<T,DESCRIPTOR>(param.cutOffSpeedSqr),
            lattice->getBoundingBox(), particleArg, 0);
    // Functional that assigns the particle velocity according to the particle's position in the fluid.
    integrateProcessingFunctional (
            new FluidToParticleCoupling3D<T,DESCRIPTOR>((T) param.particleTimeFactor),
            lattice->getBoundingBox(), particleFluidArg, 1 );

    // Definition of a domain from which particles will be injected in the flow field.
    Box3D injectionDomain(0, 0, centerLB[1]-0.25*param.ny, centerLB[1]+0.25*param.ny,
            centerLB[2]-0.25*, centerLB[2]+0.25*;

    // Definition of simple mass-less particles.
    Particle3D<T,DESCRIPTOR>* particleTemplate=0;
    particleTemplate = new PointParticle3D<T,DESCRIPTOR>(0, Array<T,3>(0.,0.,0.), Array<T,3>(0.,0.,0.));

    // Functional which injects particles with predefined probability from the specified injection domain.
    std::vector<MultiBlock3D*> particleInjectionArg;

    integrateProcessingFunctional (
            new InjectRandomParticlesFunctional3D<T,DESCRIPTOR>(particleTemplate, param.particleProbabilityPerCell),
            injectionDomain, particleInjectionArg, 0 );

    // Definition of an absorbtion domain for the particles.
    Box3D absorbtionDomain(param.outlet);

    // Functional which absorbs the particles which reach the specified absorbtion domain.
    integrateProcessingFunctional (
            new AbsorbParticlesFunctional3D<T,DESCRIPTOR>, absorbtionDomain, particleArg, 0 );


 * Starting the simulation.

plb_ofstream energyFile((outputDir+"average_energy.dat").c_str());

pcout << std::endl;
pcout << "Starting simulation." << std::endl;
for (plint i = 0; i < param.maxIter; ++i) {
    if (i <= param.initialIter) {
        Array<T,3> uBoundary(param.getInletVelocity(i), 0.0, 0.0);
        setBoundaryVelocity(*lattice, param.inlet, uBoundary);

    if (i % param.statIter == 0) {
         pcout << "At iteration " << i << ", t = " << i*param.dt << std::endl;
         Array<T,3> force(boundaryCondition->getForceOnObject());
         T factor = util::sqr(util::sqr(param.dx)) / util::sqr(param.dt);
         pcout << "Force on object over fluid density: F[x] = " << force[0]*factor << ", F[y] = "
               << force[1]*factor << ", F[z] = " << force[2]*factor << std::endl;
         T avEnergy = boundaryCondition->computeAverageEnergy() * util::sqr(param.dx) / util::sqr(param.dt);
         pcout << "Average kinetic energy over fluid density: E = " << avEnergy << std::endl;
         energyFile << i*param.dt << "  " << avEnergy << std::endl;
         pcout << std::endl;

    if (i % param.vtkIter == 0) {
        pcout << "Writing VTK at time t = " << i*param.dt << endl;
        writeVTK(*boundaryCondition, i);
        if (param.useParticles) {
            writeParticleVtk(*particles, createFileName(outputDir+"particles_", i, PADDING) + ".vtk",

    if (i % param.imageIter == 0) {
        pcout << "Writing PPM image at time t = " << i*param.dt << endl;
        writePPM(*boundaryCondition, i);

    if (param.useParticles && i % param.particleTimeFactor == 0) {

delete outerBoundaryCondition;
delete boundaryCondition;
if (param.useParticles) {
    delete particles;
delete j;
delete rhoBar;
delete lattice;


int main(int argc, char* argv[])
plbInit(&argc, &argv);

// The try-catch blocks catch exceptions in case an error occurs,
// and terminate the program properly with a nice error message.

// 1. Read command-line parameter: the input file name.
string xmlFileName;
try {
catch (PlbIOException& exception) {
    pcout << "Wrong parameters; the syntax is: " 
          << (std::string)global::argv(0) << " input-file.xml" << std::endl;
    return -1;

// 2. Read input parameters from the XML file.
try {
    param = Param(xmlFileName);
catch (PlbIOException& exception) {
    pcout << exception.what() << std::endl;
    return -1;

// 3. Execute the main program.
try {
catch (PlbIOException& exception) {
    pcout << exception.what() << std::endl;
    return -1;


I reuploaded the images, tell me if you can see them now. It is not inside the code.

Sry for late reply.
Ya, I can see your image already, but I run the program after set the argument, it give me another error.
Is it that i need set the argument as address of the xml file??
Below is the image that I did and I having an error.

Seems to have problem reading the xml. Try putting it in a simpler directory with no blank spaces.

I have put the xml file in user folder and type the address as ’ user\externalFlowAroundObstacle.xml’ in the program argument. However,it shows me the same error.
Is it my address folder that put in the program argument is wrong. (I mean the way to write it).
And may I know the file that you success run is in codeblock is which version??

The easiest way is to put the xml file in the same folder where the palabos.cpp is and then only pass the argumen “externalFlowAroundObstacle.xml”. Be careful that the local directories are based on the situation of the Palabos.cpp file. If you keep struggling contact me at and I would try to help you further.

Hi NewPalabos User

Have the .xml file and the to be implemented code file (after make command) in the same folder.
If you want to execute the code just type
“./externalFlowAroundObstacle externalFlowAroundObstacle.xml” (observe the space in between)
The above is for Linux terminal (ctrl+alt+T) in Ubuntu. and you navigate to that folder by ( cd etc etc ! )

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