nonLinearCF.hpp

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/*------------------------------- phasicFlow ---------------------------------
      O        C enter of
     O O       E ngineering and
    O   O      M ultiscale modeling of
   OOOOOOO     F luid flow       
------------------------------------------------------------------------------
  Copyright (C): www.cemf.ir
  email: hamid.r.norouzi AT gmail.com
------------------------------------------------------------------------------  
Licence:
  This file is part of phasicFlow code. It is a free software for simulating 
  granular and multiphase flows. You can redistribute it and/or modify it under
  the terms of GNU General Public License v3 or any other later versions. 
 
  phasicFlow is distributed to help others in their research in the field of 
  granular and multiphase flows, but WITHOUT ANY WARRANTY; without even the
  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 
-----------------------------------------------------------------------------*/
 
#ifndef __nonLinearCF_hpp__
#define __nonLinearCF_hpp__
 
#include "types.hpp"
 
namespace pFlow::cfModels
{
 
template<bool limited=true>
class nonLinear
{
public:
 
    struct contactForceStorage
    {
        realx3 overlap_t_ = 0.0;
    };
 
    struct nonLinearProperties
    {       
        real    Yeff_   = 1000000.0;
        real    Geff_   = 8000000.0;
        real    ethan_= 0.0;
        real  mu_   = 0.00001;
 
        INLINE_FUNCTION_HD
        nonLinearProperties(){}
 
        INLINE_FUNCTION_HD
        nonLinearProperties(real Yeff, real Geff, real etha_n, real mu ):
            Yeff_(Yeff), Geff_(Geff), ethan_(etha_n), mu_(mu)
        {}      
 
        INLINE_FUNCTION_HD
        nonLinearProperties(const nonLinearProperties&)=default;
 
        INLINE_FUNCTION_HD
        nonLinearProperties& operator=(const nonLinearProperties&)=default;
 
        INLINE_FUNCTION_HD
        ~nonLinearProperties() = default;
    };
 
protected:
 
    using NonLinearArrayType =  symArray<nonLinearProperties>;
 
    int32                       numMaterial_ = 0;
 
    ViewType1D<real>            rho_;
 
    NonLinearArrayType          nonlinearProperties_;
 
    bool readNonLinearDictionary(const dictionary& dict)
    {
        auto Yeff = dict.getVal<realVector>("Yeff");
        auto Geff = dict.getVal<realVector>("Geff");
        auto nu = dict.getVal<realVector>("nu");
        auto en = dict.getVal<realVector>("en");
        auto mu = dict.getVal<realVector>("mu");
 
        auto nElem = Yeff.size();
 
        if(nElem != nu.size())
        {
            fatalErrorInFunction<<
            "sizes of Yeff("<<nElem<<") and nu("<<nu.size()<<") do not match.\n";
            return false;
        }
 
        if(nElem != en.size())
        {
            fatalErrorInFunction<<
            "sizes of Yeff("<<nElem<<") and en("<<en.size()<<") do not match.\n";
            return false;
        }
 
 
        if(nElem != mu.size())
        {
            fatalErrorInFunction<<
            "sizes of Yeff("<<nElem<<") and mu("<<mu.size()<<") do not match.\n";
            return false;
        }
 
        
        // check if size of vector matchs a symetric array
        uint32 nMat;
        if( !NonLinearArrayType::getN(nElem, nMat) )
        {
            fatalErrorInFunction<<
            "sizes of properties do not match a symetric array with size ("<<
            numMaterial_<<"x"<<numMaterial_<<").\n";
            return false;
        }
        else if( numMaterial_ != nMat)
        {
            fatalErrorInFunction<<
            "size mismatch for porperties. \n";
            return false;
        }
 
 
        realVector etha_n("etha_n",nElem);
        
        ForAll(i , en)
        {
            //K_hertz = 4.0/3.0*Yeff*sqrt(Reff); 
            //-2.2664*log(en)*sqrt(meff*K_hertz)/sqrt( log(en)**2 + 10.1354);
 
            // we take out sqrt(meff*K_hertz) here and then consider this term 
            // when calculating damping part. 
            etha_n[i] = -2.2664*log(en[i])/
                    sqrt(pow(log(en[i]),2.0)+ pow(Pi,2.0));
 
            // no damping for tangential part 
 
        }
 
        Vector<nonLinearProperties> prop("prop",nElem);
        ForAll(i,Yeff)
        {
            prop[i] = {Yeff[i], Geff[i], etha_n[i], mu[i]};
        }
 
        nonlinearProperties_.assign(prop);
 
        return true;
 
    }
 
    static const char* modelName()
    {
        if constexpr (limited)
        {
            return "nonLinearLimited";
        }
        else
        {
            return "nonLinearNonLimited";
        }
        return "";
    }
 
public:
 
    TypeInfoNV(modelName());
 
    INLINE_FUNCTION_HD
    nonLinear(){}
 
    nonLinear(
        int32 nMaterial,
        const ViewType1D<real>& rho,
        const dictionary& dict)
    :
        numMaterial_(nMaterial),
        rho_("rho",nMaterial),
        nonlinearProperties_("nonLinearProperties",nMaterial)
    {
 
        Kokkos::deep_copy(rho_,rho);
        if(!readNonLinearDictionary(dict))
        {
            fatalExit;
        }
    }
    
    INLINE_FUNCTION_HD
    nonLinear(const nonLinear&) = default;
 
    INLINE_FUNCTION_HD
    nonLinear(nonLinear&&) = default;
 
    INLINE_FUNCTION_HD
    nonLinear& operator=(const nonLinear&) = default;
 
    INLINE_FUNCTION_HD
    nonLinear& operator=(nonLinear&&) = default;
 
 
    INLINE_FUNCTION_HD
    ~nonLinear()=default;
 
    INLINE_FUNCTION_HD
    int32 numMaterial()const
    {
        return numMaterial_;
    }
 
 
    INLINE_FUNCTION_HD
    void contactForce
    (
        const real dt,
        const uint32 i,
        const uint32 j,
        const uint32 propId_i,
        const uint32 propId_j,
        const real Ri,
        const real Rj,
        const real ovrlp_n,
        const realx3& Vr,
        const realx3& Nij,
        contactForceStorage& history,
        realx3& FCn,
        realx3& FCt
    )const
    {
 
        auto prop = nonlinearProperties_(propId_i,propId_j);
 
 
        real vrn = dot(Vr, Nij);    
        realx3 Vt = Vr - vrn*Nij;
 
        history.overlap_t_ += Vt*dt;
 
        real mi = 3*Pi/4*pow(Ri,static_cast<real>(3))*rho_[propId_i];
        real mj = 3*Pi/4*pow(Rj,static_cast<real>(3))*rho_[propId_j];
        real Reff = 1.0/(1/Ri + 1/Rj);
 
        real K_hertz = 4.0/3.0*prop.Yeff_*sqrt(Reff);
        real sqrt_meff_K_hertz = sqrt((mi*mj)/(mi+mj) * K_hertz);
 
        FCn = (static_cast<real>(-4.0/3.0) * prop.Yeff_ * sqrt(Reff)* pow(ovrlp_n,static_cast<real>(1.5)) - 
               sqrt_meff_K_hertz*prop.ethan_*pow(ovrlp_n,static_cast<real>(0.25))*vrn)*Nij;
 
        FCt = (- static_cast<real>(8.0) * prop.Geff_ * sqrt(Reff*ovrlp_n) ) * history.overlap_t_;
 
        real ft = length(FCt);
        real ft_fric = prop.mu_ * length(FCn);
 
        // apply friction 
        if(ft > ft_fric)
        {
            if( length(history.overlap_t_) >0.0)
            {
                if constexpr (limited)
                {
                    real kt = static_cast<real>(8.0) * prop.Geff_ * sqrt(Reff*ovrlp_n);
                    FCt *= (ft_fric/ft);
                    history.overlap_t_ = - (FCt/kt);
                }
                else
                {
                    FCt = (FCt/ft)*ft_fric; 
                }
                
            }
            else
            {
                FCt = 0.0;
            }
        }
 
    }
   
 
};
 
} //pFlow::CFModels
 
#endif