56 temperature = clamp(temperature, 1e-9, 500.0);
57 pressure = clamp(pressure, 0.0, 1e8);
63 const Scalar M_x = 1e3*Xylene::molarMass();
64 const Scalar M_a = 1e3*Air::molarMass();
65 const Scalar Tb_x = 412.0;
66 const Scalar sigma_a = 3.711;
67 const Scalar T_scal_a = 78.6;
68 const Scalar V_B_x = 140.4;
69 const Scalar sigma_x = 1.18*pow(V_B_x, 0.333);
70 const Scalar sigma_ax = 0.5*(sigma_a + sigma_x);
71 const Scalar T_scal_x = 1.15*Tb_x;
72 const Scalar T_scal_ax = sqrt(T_scal_a*T_scal_x);
75 Scalar T_star = temperature/T_scal_ax;
76 T_star = max(T_star, 1e-5);
78 const Scalar Omega = 1.06036/pow(T_star, 0.1561) + 0.193/exp(T_star*0.47635)
79 + 1.03587/exp(T_star*1.52996) + 1.76474/exp(T_star*3.89411);
80 const Scalar B_ = 0.00217 - 0.0005*sqrt(1.0/M_a + 1.0/M_x);
81 const Scalar Mr = (M_a + M_x)/(M_a*M_x);
82 const Scalar D_ax = (B_*pow(temperature,1.5)*sqrt(Mr))
83 /(1e-5*pressure*power(sigma_ax, 2)*Omega);