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mie.hpp 3.28 KiB
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#pragma once

#include "teqp/models/multifluid.hpp"
#include <Eigen/Dense>

namespace teqp {
namespace Mie{

    /**
     Equation of state for the Mie ($\lambda_{\mathrm{r}}$,6) fluid with a repulsive exponent from 11 to 13
     Pohl, S.; Fingerhut, R., Thol, M.; Vrabec, J.; Span, R.
     */
    class Mie6Pohl2023 {
        
    private:
        using EArray6 = Eigen::Array<double, 6, 1>;
        using EArray4 = Eigen::Array<double, 4, 1>;
        
        const EArray6 c1_pol = (EArray6() << -0.0192944,1.38,-2.2653,1.6291,-1.974,0.40412 ).finished();
        const EArray6 c1_exp = (EArray6() <<  0.1845,-0.3227,1.1351,2.232,-2.344,-0.4238 ).finished();
        const EArray4 c1_gbs = (EArray4() <<  -4.367,0.0371,1.3895,2.835 ).finished();
        const EArray6 c2_pol = (EArray6() <<  0.26021,-5.525,8.329,-19.492,25.8,-3.8133 ).finished();
        const EArray6 c2_exp = (EArray6() <<  -5.05,2.7842,-9.523,-30.383,17.902,2.2264 ).finished();
        const EArray4 c2_gbs = (EArray4() <<  48.445,-5.506,-11.643,-24.36 ).finished();
        const EArray6 t_pol = (EArray6() <<  1,0.236,0.872,0.313,0.407,0.703 ).finished();
        const EArray6 t_exp = (EArray6() <<  1.78,2.99,2.866,1.2,3.06,1.073 ).finished();
        const EArray4 t_gbs = (EArray4() <<  1.50,1.03,4.02,1.57 ).finished();
        const EArray6 d_pol = (EArray6() <<  4,1,1,2,2,3 ).finished();
        const EArray6 d_exp = (EArray6() <<  1,1,3,2,2,5 ).finished();
        const EArray4 d_gbs = (EArray4() <<  2,3,2,2 ).finished();
        const EArray6 p = (EArray6() <<  1,2,2,1,2,1 ).finished();
        const EArray4 eta = (EArray4() <<  0.362,0.313,1.17,0.957 ).finished();
        const EArray4 beta = (EArray4() <<  0.0761,0.143,0.63,1.32 ).finished();
        const EArray4 gam = (EArray4() <<  1.55,-0.0826,1.505,1.07 ).finished();
        const EArray4 eps = (EArray4() <<  -1,-1,-0.195,-0.287 ).finished();
        
        const double m_lambda_a;
        const EArray6 n_pol, n_exp;
        const EArray4 n_gbs;
        const double Tc, rhoc; // In simulation units
    public:
        
        Mie6Pohl2023(double lambda_a) : m_lambda_a(lambda_a),
        n_pol(c1_pol + c2_pol / m_lambda_a),
        n_exp(c1_exp + c2_exp / m_lambda_a),
        n_gbs(c1_gbs + c2_gbs / m_lambda_a),
        Tc(0.668 + 6.84 / m_lambda_a + 145 / pow(m_lambda_a, 3)), // T^*
        rhoc(0.2516 + 0.049 * log10(m_lambda_a)) // rho^*
        {}
        
        auto get_lambda_a() const { return m_lambda_a; }

        // We are in "simulation units", so R is 1.0, and T and rho that
        // go into alphar are actually T^* and rho^*
        template<typename MoleFracType>
        double R(const MoleFracType &) const { return 1.0; }

        template<typename TTYPE, typename RHOTYPE, typename MoleFracType>
        auto alphar(const TTYPE& Tstar, const RHOTYPE& rhostar, const MoleFracType& /*molefrac*/) const {
            auto tau = Tc / Tstar; auto delta = rhostar / rhoc;
            auto alphar_ = (
                (n_pol * pow(tau, t_pol) * pow(delta, d_pol)).sum() +
                (n_exp * pow(tau, t_exp) * pow(delta, d_exp) * exp(-pow(delta, p))).sum() +
                (n_gbs * pow(tau, t_gbs) * pow(delta, d_gbs) * exp(-eta * pow(delta - eps, 2) - beta * pow(tau - gam, 2))).sum()
            );
            return forceeval(alphar_);
        }

    };

};
};