vhlle/src/trancoeff.h

0001 class EoS ;
0002
0003 // this class contains the information about the transport coefficients
0004 // of the fluid: eta/s, zeta/s and the corresponding relaxation times,
0005 // taupi (\tau_\pi) and tauPi (\tau_\Pi)
0006 class TransportCoeff
0007 {
0008  double etaS, zetaS, taupi, tauPi ;
0009  EoS *eos ; // EoS instance is needed optionally for zeta/s parametrization, which depends on the speed of sound
0010  public:
0011  TransportCoeff(double _etaS, double _zetaS, EoS *_eos) ;
0012  ~TransportCoeff() {} ;
0013  // returns (optionally temperature dependent) eta/s and zeta/s
0014  void getEta(double e, double T, double &_etaS, double &_zetaS) ;
0015  // returns shear and bulk relaxation times
0016  void getTau(double T, double &_taupi, double &_tauPi) ;
0017  // isViscous tells whether the fluid is viscous or inviscid
0018  inline bool isViscous() { if(etaS>0. || zetaS>0.) return true ; else return false ; }
0019 } ;