rksgasmodel.h

气体热力性质计算程序

/*============================================================
                        Introduction
  This is the computation of O.Redlich - J.N.S.Kwong's model,
which is revised from ver de Waals equation. The form of this 
equation is like this:
		
		     p=RgT/(v-b)-a/[T^0.5*v(v+b)]

This equation is much acute than the var de Waals. But the 
square root is induced into this one. The computation on this 
equation should become much more complex. The accuracy of this
equation is so satisfactory when when the temperature is above
the critical temperature under any pressure. Besides, the 
brevity of this equation also attracts many attentions on it.
------------------------------------------------------------*/
#pragma once

#ifndef x_RKSGAS
#define x_RKSGAS
#endif

#include "GasBase.h"

namespace XZGas
{    
    class RKSGasModel:public GasModel
    {
    public:
        RKSGasModel(const GasData &gas);
        ~RKSGasModel();

        inline double Cp(double TT,double pp);
		inline double Cv(double TT,double vv);
	
		inline double Gama(double TT,double pp);

		inline double h(double TT,double pp);
		inline double u(double TT,double vv);
		inline double s(double x,double y,Pid id);
		
        inline double p(double TT,double vv);
        inline double v(double TT,double pp);
        inline double T(double pp,double vv);	

		inline double Alphav(double pp,double vv);
		inline double KT(double TT,double vv);
		inline double Beta(double pp,double vv);
    
	private:
		//the derivative of p above v with T as a constant
		inline double dpdvT(double TT,double vv);
		//the derivative of p above T with v as a constant
		inline double dpdTv(double pp,double vT,double TT=-1.0);
		
		double a;
        double b;
    };
}