weakly_compressible_fluid.h

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/* -------------------------------------------------------------------------*
 *                              SPHinXsys                                   *
 * --------------------------------------------------------------------------*
 * SPHinXsys (pronunciation: s'finksis) is an acronym from Smoothed Particle    *
 * Hydrodynamics for industrial compleX systems. It provides C++ APIs for   *
 * physical accurate simulation and aims to model coupled industrial dynamic *
 * systems including fluid, solid, multi-body dynamics and beyond with SPH  *
 * (smoothed particle hydrodynamics), a meshless computational method using *
 * particle discretization.                                                 *
 *                                                                          *
 * SPHinXsys is partially funded by German Research Foundation              *
 * (Deutsche Forschungsgemeinschaft) DFG HU1527/6-1, HU1527/10-1                *
 * and HU1527/12-1.                                                         *
 *                                                                           *
 * Portions copyright (c) 2017-2020 Technical University of Munich and      *
 * the authors' affiliations.                                               *
 *                                                                           *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may   *
 * not use this file except in compliance with the License. You may obtain a *
 * copy of the License at http://www.apache.org/licenses/LICENSE-2.0.        *
 *                                                                           *
 * --------------------------------------------------------------------------*/
#ifndef WEAKLY_COMPRESSIBLE_FLUID_H
#define WEAKLY_COMPRESSIBLE_FLUID_H

#include "base_material.h"

namespace SPH
{
    class WeaklyCompressibleFluid : public Fluid
    {
    protected:
        Real c0_, p0_; 
    public:
        explicit WeaklyCompressibleFluid(Real rho0, Real c0, Real mu = 0.0)
            : Fluid(rho0, mu), c0_(c0), p0_(rho0 * c0 * c0)
        {
            material_type_name_ = "WeaklyCompressibleFluid";
        };
        virtual ~WeaklyCompressibleFluid(){};

        Real ReferenceSoundSpeed() { return c0_; };
        virtual Real getPressure(Real rho) override;
        virtual Real DensityFromPressure(Real p) override;
        virtual Real getSoundSpeed(Real p = 0.0, Real rho = 1.0) override;
        virtual WeaklyCompressibleFluid *ThisObjectPtr() override { return this; };
    };

    template <class WeaklyCompressibleFluidType>
    class WeaklyCompressibleFluidFreeSurface : public WeaklyCompressibleFluidType
    {
    protected:
        Real cutoff_pressure_, cutoff_density_;

    public:
        template <typename... ConstructorArgs>
        explicit WeaklyCompressibleFluidFreeSurface(Real cutoff_pressure, ConstructorArgs &&...args)
            : WeaklyCompressibleFluidType(std::forward<ConstructorArgs>(args)...),
              cutoff_pressure_(cutoff_pressure),
              cutoff_density_(WeaklyCompressibleFluidType::DensityFromPressure(cutoff_pressure))
        {
            WeaklyCompressibleFluidType::aterial_type_ += "FreeSurface";
        };
        virtual ~WeaklyCompressibleFluidFreeSurface(){};

        virtual Real getPressure(Real rho) override
        {
            return rho < cutoff_density_ ? cutoff_pressure_ : WeaklyCompressibleFluid::getPressure(rho);
        };
    };

    class SymmetricTaitFluid : public WeaklyCompressibleFluid
    {
    protected:
        int gamma_; 
    public:
        explicit SymmetricTaitFluid(Real rho0, Real c0, int gamma)
            : WeaklyCompressibleFluid(rho0, c0), gamma_(gamma)
        {
            material_type_name_ = "SymmetricTaitFluid";
        };
        virtual ~SymmetricTaitFluid(){};

        virtual Real getPressure(Real rho) override;
        virtual Real DensityFromPressure(Real p) override;
        virtual Real getSoundSpeed(Real p = 0.0, Real rho = 1.0) override;
    };

    class Oldroyd_B_Fluid : public WeaklyCompressibleFluid
    {
    protected:
        Real lambda_; 
        Real mu_p_;   
    public:
        explicit Oldroyd_B_Fluid(Real rho0, Real c0, Real mu, Real lambda, Real mu_p)
            : WeaklyCompressibleFluid(rho0, c0, mu), lambda_(lambda), mu_p_(mu_p)
        {
            material_type_name_ = "Oldroyd_B_Fluid";
        };
        virtual ~Oldroyd_B_Fluid(){};

        Real getReferenceRelaxationTime() { return lambda_; };
        Real ReferencePolymericViscosity() { return mu_p_; };
        virtual Oldroyd_B_Fluid *ThisObjectPtr() override { return this; };
    };
}
#endif // WEAKLY_COMPRESSIBLE_FLUID_H