main.cpp

 
//#define SE_CLASS1
//#define STOP_ON_ERROR
 
#include "Vector/vector_dist.hpp"
#include <math.h>
#include "Draw/DrawParticles.hpp"
 
// A constant to indicate boundary particles
#define BOUNDARY 1
 
// A constant to indicate fluid particles
#define FLUID 0
 
// initial spacing between particles dp in the formulas
const double dp = 0.0085;
// Maximum height of the fluid water
// is going to be calculated and filled later on
double h_swl = 0.0;
 
// c_s in the formulas (constant used to calculate the sound speed)
const double coeff_sound = 20.0;
 
// gamma in the formulas
const double gamma_ = 7.0;
 
// sqrt(3.0*dp*dp) support of the kernel
const double H = 0.0147224318643;
 
const double FourH2 = 4.0 * H*H;
 
// Eta in the formulas
const double Eta2 = 0.01 * H*H;
 
// alpha in the formula
const double visco = 0.1;
 
// cbar in the formula (calculated later)
double cbar = 0.0;
 
// Mass of the fluid particles
const double MassFluid = 0.000614125;
 
// Mass of the boundary particles
const double MassBound = 0.000614125;
 
// End simulation time
#ifndef TEST_RUN
const double t_end = 1.5;
#else
const double t_end = 0.001;
#endif
 
// Gravity acceleration
const double gravity = 9.81;
 
// Reference densitu 1000Kg/m^3
const double rho_zero = 1000.0;
 
// Filled later require h_swl, it is b in the formulas
double B = 0.0;
 
// Constant used to define time integration
const double CFLnumber = 0.2;
 
// Minimum T
const double DtMin = 0.00001;
 
// Minimum Rho allowed
const double RhoMin = 700.0;
 
// Maximum Rho allowed
const double RhoMax = 1300.0;
 
// Filled in initialization
double max_fluid_height = 0.0;
 
// Properties
 
// FLUID or BOUNDARY
const size_t type = 0;
 
// FLUID or BOUNDARY
const size_t nn_num = 1;
 
// Density
const int rho = 2;
 
// Density at step n-1
const int rho_prev = 3;
 
// Pressure
const int Pressure = 4;
 
// Delta rho calculated in the force calculation
const int drho = 5;
 
// calculated force
const int force = 6;
 
// velocity
const int velocity = 7;
 
// velocity at previous step
const int velocity_prev = 8;
 
// Type of the vector containing particles
typedef vector_dist<3,double,aggregate<int, int,double,  double,    double,     double,     double[3], double[3], double[3]> > particles;
//                                       |   |    |        |          |            |            |         |            |
//                                       |   |    |        |          |            |            |         |            |
//                                     type  |  density   density    Pressure    delta       force     velocity    velocity
//                                           |           at n-1                 density                           at n - 1
//                                           |
//                                  Number of neighborhood
 
struct ModelCustom
{
    template<typename Decomposition, typename vector> inline void addComputation(Decomposition & dec, vector & vd, size_t v, size_t p)
    {
                if (vd.template getProp<type>(p) == FLUID )
                {dec.addComputationCost(v,4);}
                else
                {dec.addComputationCost(v,3);}
    }
 
    template<typename Decomposition> inline void applyModel(Decomposition & dec, size_t v)
    {
        dec.setSubSubDomainComputationCost(v, dec.getSubSubDomainComputationCost(v) * dec.getSubSubDomainComputationCost(v));
    }
 
    float distributionTol()
    {
        return 1.01;
    }
};
 
struct ModelCustom2
{
    template<typename Decomposition, typename vector> inline void addComputation(Decomposition & dec, vector & vd, size_t v, size_t p)
    {
        dec.addComputationCost(v,vd.template getProp<nn_num>(p) + 4);
    }
 
    template<typename Decomposition> inline void applyModel(Decomposition & dec, size_t v)
    {
    }
 
    float distributionTol()
    {
            return 1.01;
    }
};
 
inline void EqState(particles & vd)
{
    auto it = vd.getDomainIterator();
 
    while (it.isNext())
    {
        auto a = it.get();
 
        double rho_a = vd.template getProp<rho>(a);
        double rho_frac = rho_a / rho_zero;
 
        vd.template getProp<Pressure>(a) = B*( rho_frac*rho_frac*rho_frac*rho_frac*rho_frac*rho_frac*rho_frac - 1.0);
 
        ++it;
    }
}
 
const double a2 = 1.0/M_PI/H/H/H;
 
inline double Wab(double r)
{
    r /= H;
 
    if (r < 1.0)
    {return (1.0 - 3.0/2.0*r*r + 3.0/4.0*r*r*r)*a2;}
    else if (r < 2.0)
    {return (1.0/4.0*(2.0 - r*r)*(2.0 - r*r)*(2.0 - r*r))*a2;}
    else
    {return 0.0;}
}
 
const double c1 = -3.0/M_PI/H/H/H/H;
const double d1 = 9.0/4.0/M_PI/H/H/H/H;
const double c2 = -3.0/4.0/M_PI/H/H/H/H;
const double a2_4 = 0.25*a2;
// Filled later
double W_dap = 0.0;
 
inline void DWab(Point<3,double> & dx, Point<3,double> & DW, double r)
{
    const double qq=r/H;
 
    double qq2 = qq * qq;
    double fac1 = (c1*qq + d1*qq2)/r;
    double b1 = (qq < 1.0)?1.0f:0.0f;
 
    double wqq = (2.0 - qq);
    double fac2 = c2 * wqq * wqq / r;
    double b2 = (qq >= 1.0 && qq < 2.0)?1.0f:0.0f;
 
    double factor = (b1*fac1 + b2*fac2);
 
    DW.get(0) = factor * dx.get(0);
    DW.get(1) = factor * dx.get(1);
    DW.get(2) = factor * dx.get(2);
}
 
inline double Tensile(double r, double rhoa, double rhob, double prs1, double prs2)
{
    const double qq=r/H;
    //-Cubic Spline kernel
    double wab;
    if(r>H)
    {
        double wqq1=2.0f-qq;
        double wqq2=wqq1*wqq1;
 
        wab=a2_4*(wqq2*wqq1);
    }
    else
    {
        double wqq2=qq*qq;
        double wqq3=wqq2*qq;
 
        wab=a2*(1.0f-1.5f*wqq2+0.75f*wqq3);
    }
 
    //-Tensile correction.
    double fab=wab*W_dap;
    fab*=fab; fab*=fab; //fab=fab^4
    const double tensilp1=(prs1/(rhoa*rhoa))*(prs1>0? 0.01: -0.2);
    const double tensilp2=(prs2/(rhob*rhob))*(prs2>0? 0.01: -0.2);
 
    return (fab*(tensilp1+tensilp2));
}
 
 
inline double Pi(const Point<3,double> & dr, double rr2, Point<3,double> & dv, double rhoa, double rhob, double massb, double & visc)
{
    const double dot = dr.get(0)*dv.get(0) + dr.get(1)*dv.get(1) + dr.get(2)*dv.get(2);
    const double dot_rr2 = dot/(rr2+Eta2);
    visc=std::max(dot_rr2,visc);
 
    if(dot < 0)
    {
        const float amubar=H*dot_rr2;
        const float robar=(rhoa+rhob)*0.5f;
        const float pi_visc=(-visco*cbar*amubar/robar);
 
        return pi_visc;
    }
    else
        return 0.0;
}
 
 
template<typename VerletList> inline void calc_forces(particles & vd, VerletList & NN, double & max_visc)
{
    // Reset the ghost
    auto itg = vd.getDomainIterator();
    while (itg.isNext())
    {
        auto p = itg.get();
        // Reset force
 
        // Reset the force counter (- gravity on zeta direction)
        vd.template getProp<force>(p)[0] = 0.0;
        vd.template getProp<force>(p)[1] = 0.0;
        vd.template getProp<force>(p)[2] = -gravity;
        vd.template getProp<drho>(p) = 0.0;
 
 
        ++itg;
    }
 
    auto itg2 = vd.getGhostIterator();
    while (itg2.isNext())
    {
        auto p = itg2.get();
        // Reset force
 
        // Reset the force counter (- gravity on zeta direction)
        vd.template getProp<force>(p)[0] = 0.0;
        vd.template getProp<force>(p)[1] = 0.0;
        vd.template getProp<force>(p)[2] = 0.0;
        vd.template getProp<drho>(p) = 0.0;
 
        ++itg2;
    }
 
    // Get an iterator over particles
    auto part = vd.getParticleIteratorCRS(NN);
 
    double visc = 0;
 
    // For each particle ...
    while (part.isNext())
    {
        // ... a
        auto a = part.get();
 
        // Get the position xp of the particle
        Point<3,double> xa = vd.getPos(a);
 
        // Type of the particle
        size_t typea = vd.getProp<type>(a);
 
        // Take the mass of the particle dependently if it is FLUID or BOUNDARY
        double massa = (vd.getProp<type>(a) == FLUID)?MassFluid:MassBound;
 
        // Get the density of the of the particle a
        double rhoa = vd.getProp<rho>(a);
 
        // Get the pressure of the particle a
        double Pa = vd.getProp<Pressure>(a);
 
        // Get the Velocity of the particle a
        Point<3,double> va = vd.getProp<velocity>(a);
 
        // Get an iterator over the neighborhood particles of p
        auto Np = NN.template getNNIterator<NO_CHECK>(a);
 
        size_t nn = 0;
 
        // For each neighborhood particle
        while (Np.isNext() == true)
        {
                // ... q
                auto b = Np.get();
 
                // Get the position xp of the particle
                Point<3,double> xb = vd.getPos(b);
 
                // Get the distance between p and q
                Point<3,double> dr = xa - xb;
                // take the norm of this vector
                float r2 = norm2(dr);
 
                // if they interact
                if (r2 < FourH2 && r2 > 1e-18)
                {
                        double r = sqrt(r2);
 
                        unsigned int typeb = vd.getProp<type>(b);
 
                        double massb = (typeb == FLUID)?MassFluid:MassBound;
                        Point<3,double> vb = vd.getProp<velocity>(b);
                        double Pb = vd.getProp<Pressure>(b);
                        double rhob = vd.getProp<rho>(b);
 
                        Point<3,double> v_rel = va - vb;
 
                        Point<3,double> DW;
                        DWab(dr,DW,r);
 
 
                        double factor = - ((Pa + Pb) / (rhoa * rhob) + Tensile(r,rhoa,rhob,Pa,Pb) + Pi(dr,r2,v_rel,rhoa,rhob,massb,visc));
 
                        // Bound - Bound does not produce any change
                        factor = (typea == BOUNDARY && typeb == BOUNDARY)?0.0f:factor;
 
                        vd.getProp<force>(a)[0] += massb * factor * DW.get(0);
                        vd.getProp<force>(a)[1] += massb * factor * DW.get(1);
                        vd.getProp<force>(a)[2] += massb * factor * DW.get(2);
 
                        vd.getProp<force>(b)[0] -= massa * factor * DW.get(0);
                        vd.getProp<force>(b)[1] -= massa * factor * DW.get(1);
                        vd.getProp<force>(b)[2] -= massa * factor * DW.get(2);
 
                        double scal = (v_rel.get(0)*DW.get(0)+v_rel.get(1)*DW.get(1)+v_rel.get(2)*DW.get(2));
 
                        // Bound - Bound does not produce any change
                        scal = (typea == BOUNDARY && typeb == BOUNDARY)?0.0f:scal;
 
                        vd.getProp<drho>(a) += massb*scal;
                        vd.getProp<drho>(b) += massa*scal;
 
                }
 
                nn++;
                ++Np;
        }
 
        // Number of particles here
        vd.getProp<nn_num>(a) = nn;
 
        ++part;
    }
 
 
    vd.template ghost_put<add_,drho,force>();
 
}
 
void max_acceleration_and_velocity(particles & vd, double & max_acc, double & max_vel)
{
    // Calculate the maximum acceleration
    auto part = vd.getDomainIterator();
 
    while (part.isNext())
    {
        auto a = part.get();
 
        Point<3,double> acc(vd.getProp<force>(a));
        double acc2 = norm2(acc);
 
        Point<3,double> vel(vd.getProp<velocity>(a));
        double vel2 = norm2(vel);
 
        if (vel2 >= max_vel)
            max_vel = vel2;
 
        if (acc2 >= max_acc)
            max_acc = acc2;
 
        ++part;
    }
    max_acc = sqrt(max_acc);
    max_vel = sqrt(max_vel);
 
    Vcluster<> & v_cl = create_vcluster();
    v_cl.max(max_acc);
    v_cl.max(max_vel);
    v_cl.execute();
}
 
double calc_deltaT(particles & vd, double ViscDtMax)
{
    double Maxacc = 0.0;
    double Maxvel = 0.0;
    max_acceleration_and_velocity(vd,Maxacc,Maxvel);
 
    //-dt1 depends on force per unit mass.
    const double dt_f = (Maxacc)?sqrt(H/Maxacc):std::numeric_limits<int>::max();
 
    //-dt2 combines the Courant and the viscous time-step controls.
    const double dt_cv = H/(std::max(cbar,Maxvel*10.) + H*ViscDtMax);
 
    //-dt new value of time step.
    double dt=double(CFLnumber)*std::min(dt_f,dt_cv);
    if(dt<double(DtMin))
    {dt=double(DtMin);}
 
    return dt;
}
 
 
openfpm::vector<size_t> to_remove;
 
size_t cnt = 0;
 
void verlet_int(particles & vd, double dt, double & max_disp)
{
    // list of the particle to remove
    to_remove.clear();
 
    // particle iterator
    auto part = vd.getDomainIterator();
 
    double dt205 = dt*dt*0.5;
    double dt2 = dt*2.0;
 
    max_disp = 0;
    // For each particle ...
    while (part.isNext())
    {
        // ... a
        auto a = part.get();
 
        // if the particle is boundary
        if (vd.template getProp<type>(a) == BOUNDARY)
        {
            // Update rho
            double rhop = vd.template getProp<rho>(a);
 
            // Update only the density
            vd.template getProp<velocity>(a)[0] = 0.0;
            vd.template getProp<velocity>(a)[1] = 0.0;
            vd.template getProp<velocity>(a)[2] = 0.0;
            double rhonew = vd.template getProp<rho_prev>(a) + dt2*vd.template getProp<drho>(a);
            vd.template getProp<rho>(a) = (rhonew < rho_zero)?rho_zero:rhonew;
 
            vd.template getProp<rho_prev>(a) = rhop;
 
            ++part;
            continue;
        }
 
        //-Calculate displacement and update position / Calcula desplazamiento y actualiza posicion.
        double dx = vd.template getProp<velocity>(a)[0]*dt + vd.template getProp<force>(a)[0]*dt205;
        double dy = vd.template getProp<velocity>(a)[1]*dt + vd.template getProp<force>(a)[1]*dt205;
        double dz = vd.template getProp<velocity>(a)[2]*dt + vd.template getProp<force>(a)[2]*dt205;
 
        vd.getPos(a)[0] += dx;
        vd.getPos(a)[1] += dy;
        vd.getPos(a)[2] += dz;
 
        double d2 = dx*dx + dy*dy + dz*dz;
 
        max_disp = (max_disp > d2)?max_disp:d2;
        double velX = vd.template getProp<velocity>(a)[0];
        double velY = vd.template getProp<velocity>(a)[1];
        double velZ = vd.template getProp<velocity>(a)[2];
        double rhop = vd.template getProp<rho>(a);
 
        vd.template getProp<velocity>(a)[0] = vd.template getProp<velocity_prev>(a)[0] + vd.template getProp<force>(a)[0]*dt2;
        vd.template getProp<velocity>(a)[1] = vd.template getProp<velocity_prev>(a)[1] + vd.template getProp<force>(a)[1]*dt2;
        vd.template getProp<velocity>(a)[2] = vd.template getProp<velocity_prev>(a)[2] + vd.template getProp<force>(a)[2]*dt2;
        vd.template getProp<rho>(a) = vd.template getProp<rho_prev>(a) + dt2*vd.template getProp<drho>(a);
 
        // Check if the particle go out of range in space and in density
        if (vd.getPos(a)[0] <  0.000263878 || vd.getPos(a)[1] < 0.000263878 || vd.getPos(a)[2] < 0.000263878 ||
            vd.getPos(a)[0] >  0.000263878+1.59947 || vd.getPos(a)[1] > 0.000263878+0.672972 || vd.getPos(a)[2] > 0.000263878+0.903944 ||
            vd.template getProp<rho>(a) < RhoMin || vd.template getProp<rho>(a) > RhoMax)
        {
                       to_remove.add(a.getKey());
        }
 
        vd.template getProp<velocity_prev>(a)[0] = velX;
        vd.template getProp<velocity_prev>(a)[1] = velY;
        vd.template getProp<velocity_prev>(a)[2] = velZ;
        vd.template getProp<rho_prev>(a) = rhop;
 
        ++part;
    }
 
    Vcluster<> & v_cl = create_vcluster();
    v_cl.max(max_disp);
    v_cl.execute();
 
    max_disp = sqrt(max_disp);
 
    // increment the iteration counter
    cnt++;
}
 
void euler_int(particles & vd, double dt, double & max_disp)
{
    // list of the particle to remove
    to_remove.clear();
 
    // particle iterator
    auto part = vd.getDomainIterator();
 
    double dt205 = dt*dt*0.5;
    double dt2 = dt*2.0;
 
    max_disp = 0;
 
    // For each particle ...
    while (part.isNext())
    {
        // ... a
        auto a = part.get();
 
        // if the particle is boundary
        if (vd.template getProp<type>(a) == BOUNDARY)
        {
            // Update rho
            double rhop = vd.template getProp<rho>(a);
 
            // Update only the density
            vd.template getProp<velocity>(a)[0] = 0.0;
            vd.template getProp<velocity>(a)[1] = 0.0;
            vd.template getProp<velocity>(a)[2] = 0.0;
            double rhonew = vd.template getProp<rho>(a) + dt*vd.template getProp<drho>(a);
            vd.template getProp<rho>(a) = (rhonew < rho_zero)?rho_zero:rhonew;
 
            vd.template getProp<rho_prev>(a) = rhop;
 
            ++part;
            continue;
        }
 
        //-Calculate displacement and update position / Calcula desplazamiento y actualiza posicion.
        double dx = vd.template getProp<velocity>(a)[0]*dt + vd.template getProp<force>(a)[0]*dt205;
        double dy = vd.template getProp<velocity>(a)[1]*dt + vd.template getProp<force>(a)[1]*dt205;
        double dz = vd.template getProp<velocity>(a)[2]*dt + vd.template getProp<force>(a)[2]*dt205;
 
        vd.getPos(a)[0] += dx;
        vd.getPos(a)[1] += dy;
        vd.getPos(a)[2] += dz;
 
        double d2 = dx*dx + dy*dy + dz*dz;
 
        max_disp = (max_disp > d2)?max_disp:d2;
 
        double velX = vd.template getProp<velocity>(a)[0];
        double velY = vd.template getProp<velocity>(a)[1];
        double velZ = vd.template getProp<velocity>(a)[2];
        double rhop = vd.template getProp<rho>(a);
 
        vd.template getProp<velocity>(a)[0] = vd.template getProp<velocity>(a)[0] + vd.template getProp<force>(a)[0]*dt;
        vd.template getProp<velocity>(a)[1] = vd.template getProp<velocity>(a)[1] + vd.template getProp<force>(a)[1]*dt;
        vd.template getProp<velocity>(a)[2] = vd.template getProp<velocity>(a)[2] + vd.template getProp<force>(a)[2]*dt;
        vd.template getProp<rho>(a) = vd.template getProp<rho>(a) + dt*vd.template getProp<drho>(a);
 
        // Check if the particle go out of range in space and in density
        if (vd.getPos(a)[0] <  0.000263878 || vd.getPos(a)[1] < 0.000263878 || vd.getPos(a)[2] < 0.000263878 ||
            vd.getPos(a)[0] >  0.000263878+1.59947 || vd.getPos(a)[1] > 0.000263878+0.672972 || vd.getPos(a)[2] > 0.000263878+0.903944 ||
            vd.template getProp<rho>(a) < RhoMin || vd.template getProp<rho>(a) > RhoMax)
        {
                       to_remove.add(a.getKey());
        }
 
        vd.template getProp<velocity_prev>(a)[0] = velX;
        vd.template getProp<velocity_prev>(a)[1] = velY;
        vd.template getProp<velocity_prev>(a)[2] = velZ;
        vd.template getProp<rho_prev>(a) = rhop;
 
        ++part;
    }
 
    Vcluster<> & v_cl = create_vcluster();
    v_cl.max(max_disp);
    v_cl.execute();
 
    max_disp = sqrt(max_disp);
 
    // increment the iteration counter
    cnt++;
}
 
int main(int argc, char* argv[])
{
    // initialize the library
    openfpm_init(&argc,&argv);
 
    // Here we define our domain a 2D box with internals from 0 to 1.0 for x and y
    Box<3,double> domain({-0.05,-0.05,-0.05},{1.7010,0.7065,0.5025});
    size_t sz[3] = {207,90,66};
 
    // Fill W_dap
    W_dap = 1.0/Wab(H/1.5);
 
    // Here we define the boundary conditions of our problem
    size_t bc[3]={NON_PERIODIC,NON_PERIODIC,NON_PERIODIC};
 
    double skin = 0.25 * 2*H;
    double r_gskin = 2*H + skin;
 
    // extended boundary around the domain, and the processor domain
    // by the support of the cubic kernel
    Ghost<3,double> g(r_gskin);
    
    // Eliminating the lower part of the ghost
    // We are using CRS scheme
    g.setLow(0,0.0);
    g.setLow(1,0.0);
    g.setLow(2,0.0);
 
    particles vd(0,domain,bc,g,BIND_DEC_TO_GHOST);
 
    // You can ignore all these dp/2.0 is a trick to reach the same initialization
    // of Dual-SPH that use a different criteria to draw particles
    Box<3,double> fluid_box({dp/2.0,dp/2.0,dp/2.0},{0.4+dp/2.0,0.67-dp/2.0,0.3+dp/2.0});
 
    // return an iterator to the fluid particles to add to vd
    auto fluid_it = DrawParticles::DrawBox(vd,sz,domain,fluid_box);
 
    // here we fill some of the constants needed by the simulation
    max_fluid_height = fluid_it.getBoxMargins().getHigh(2);
    h_swl = fluid_it.getBoxMargins().getHigh(2) - fluid_it.getBoxMargins().getLow(2);
    B = (coeff_sound)*(coeff_sound)*gravity*h_swl*rho_zero / gamma_;
    cbar = coeff_sound * sqrt(gravity * h_swl);
 
    // for each particle inside the fluid box ...
        while (fluid_it.isNext())
    {
        // ... add a particle ...
        vd.add();
 
        // ... and set it position ...
        vd.getLastPos()[0] = fluid_it.get().get(0);
        vd.getLastPos()[1] = fluid_it.get().get(1);
        vd.getLastPos()[2] = fluid_it.get().get(2);
 
        // and its type.
        vd.template getLastProp<type>() = FLUID;
 
        // We also initialize the density of the particle and the hydro-static pressure given by
        //
        // rho_zero*g*h = P
        //
        // rho_p = (P/B + 1)^(1/Gamma) * rho_zero
        //
 
        vd.template getLastProp<Pressure>() = rho_zero * gravity *  (max_fluid_height - fluid_it.get().get(2));
 
        vd.template getLastProp<rho>() = pow(vd.template getLastProp<Pressure>() / B + 1, 1.0/gamma_) * rho_zero;
        vd.template getLastProp<rho_prev>() = vd.template getLastProp<rho>();
        vd.template getLastProp<velocity>()[0] = 0.0;
        vd.template getLastProp<velocity>()[1] = 0.0;
        vd.template getLastProp<velocity>()[2] = 0.0;
 
        vd.template getLastProp<velocity_prev>()[0] = 0.0;
        vd.template getLastProp<velocity_prev>()[1] = 0.0;
        vd.template getLastProp<velocity_prev>()[2] = 0.0;
 
        // next fluid particle
        ++fluid_it;
        }
 
    // Recipient
    Box<3,double> recipient1({0.0,0.0,0.0},{1.6+dp/2.0,0.67+dp/2.0,0.4+dp/2.0});
    Box<3,double> recipient2({dp,dp,dp},{1.6-dp/2.0,0.67-dp/2.0,0.4+dp/2.0});
 
    Box<3,double> obstacle1({0.9,0.24-dp/2.0,0.0},{1.02+dp/2.0,0.36,0.45+dp/2.0});
    Box<3,double> obstacle2({0.9+dp,0.24+dp/2.0,0.0},{1.02-dp/2.0,0.36-dp,0.45-dp/2.0});
    Box<3,double> obstacle3({0.9+dp,0.24,0.0},{1.02,0.36,0.45});
 
    openfpm::vector<Box<3,double>> holes;
    holes.add(recipient2);
    holes.add(obstacle1);
    auto bound_box = DrawParticles::DrawSkin(vd,sz,domain,holes,recipient1);
 
    while (bound_box.isNext())
    {
        vd.add();
 
        vd.getLastPos()[0] = bound_box.get().get(0);
        vd.getLastPos()[1] = bound_box.get().get(1);
        vd.getLastPos()[2] = bound_box.get().get(2);
 
        vd.template getLastProp<type>() = BOUNDARY;
        vd.template getLastProp<rho>() = rho_zero;
        vd.template getLastProp<rho_prev>() = rho_zero;
        vd.template getLastProp<velocity>()[0] = 0.0;
        vd.template getLastProp<velocity>()[1] = 0.0;
        vd.template getLastProp<velocity>()[2] = 0.0;
 
        vd.template getLastProp<velocity_prev>()[0] = 0.0;
        vd.template getLastProp<velocity_prev>()[1] = 0.0;
        vd.template getLastProp<velocity_prev>()[2] = 0.0;
 
        ++bound_box;
    }
 
    auto obstacle_box = DrawParticles::DrawSkin(vd,sz,domain,obstacle2,obstacle1);
 
    while (obstacle_box.isNext())
    {
        vd.add();
 
        vd.getLastPos()[0] = obstacle_box.get().get(0);
        vd.getLastPos()[1] = obstacle_box.get().get(1);
        vd.getLastPos()[2] = obstacle_box.get().get(2);
 
        vd.template getLastProp<type>() = BOUNDARY;
        vd.template getLastProp<rho>() = rho_zero;
        vd.template getLastProp<rho_prev>() = rho_zero;
        vd.template getLastProp<velocity>()[0] = 0.0;
        vd.template getLastProp<velocity>()[1] = 0.0;
        vd.template getLastProp<velocity>()[2] = 0.0;
 
        vd.template getLastProp<velocity_prev>()[0] = 0.0;
        vd.template getLastProp<velocity_prev>()[1] = 0.0;
        vd.template getLastProp<velocity_prev>()[2] = 0.0;
 
        ++obstacle_box;
    }
 
    vd.map();
 
    //
    //
    //
 
    size_t tot_part = vd.size_local();
 
    auto & v_cl = create_vcluster();
    v_cl.sum(tot_part);
    v_cl.execute();
    std::cout << "SUM: " << tot_part << std::endl;
 
    // Now that we fill the vector with particles
    ModelCustom md;
 
    vd.addComputationCosts(md);
    vd.getDecomposition().decompose();
    vd.map();
 
    vd.ghost_get<type,rho,Pressure,velocity>();
 
    auto NN = vd.getVerletCrs(r_gskin);
    size_t write = 0;
    size_t it = 0;
    size_t it_reb = 0;
    double t = 0.0;
    double tot_disp = 0.0;
    double max_disp;
    while (t <= t_end)
    {
        Vcluster<> & v_cl = create_vcluster();
        timer it_time;
 
        it_reb++;
        if (2*tot_disp >= skin)
        {
            vd.remove(to_remove);
 
            vd.map();
 
            if (it_reb > 200)
            {
                ModelCustom2 md;
                vd.addComputationCosts(md);
                vd.getDecomposition().redecompose(200);
 
                vd.map();
 
                it_reb = 0;
 
                if (v_cl.getProcessUnitID() == 0)
                    std::cout << "REBALANCED " << std::endl;
 
            }
 
            // Calculate pressure from the density
            EqState(vd);
 
            vd.ghost_get<type,rho,Pressure,velocity>();
 
            vd.updateVerlet(NN,r_gskin,VL_CRS_SYMMETRIC);
            tot_disp = 0.0;
 
            if (v_cl.getProcessUnitID() == 0)
                std::cout << "RECONSTRUCT Verlet " << std::endl;
        }
        else
        {
            // Calculate pressure from the density
            EqState(vd);
 
            vd.ghost_get<type,rho,Pressure,velocity>(SKIP_LABELLING);
        }
 
        double max_visc = 0.0;
 
        // Calc forces
        calc_forces(vd,NN,max_visc);
 
        // Get the maximum viscosity term across processors
        v_cl.max(max_visc);
        v_cl.execute();
 
        // Calculate delta t integration
        double dt = calc_deltaT(vd,max_visc);
 
        // VerletStep or euler step
        it++;
        if (it < 40)
            verlet_int(vd,dt,max_disp);
        else
        {
            euler_int(vd,dt,max_disp);
            it = 0;
        }
 
        tot_disp += max_disp;
 
        t += dt;
 
        if (write < t*100)
        {
            vd.deleteGhost();
            vd.write_frame("Geometry",write,VTK_WRITER | FORMAT_BINARY);
                        vd.getDecomposition().write("dec" + std::to_string(write));
            vd.ghost_get<type,rho,Pressure,velocity>(SKIP_LABELLING);
            write++;
 
            if (v_cl.getProcessUnitID() == 0)
                std::cout << "TIME: " << t << "  write " << it_time.getwct() << "   " << v_cl.getProcessUnitID() << "  TOT disp: " << tot_disp << "    " << cnt << std::endl;
        }
        else
        {
            if (v_cl.getProcessUnitID() == 0)
                std::cout << "TIME: " << t << "  " << it_time.getwct() << "   " << v_cl.getProcessUnitID() << "  TOT disp: " << tot_disp << "    " << cnt << std::endl;
        }
    }
 
    openfpm_finalize();
}