3.125d-5 ! mu0 [Kg/m/s] - reference viscosity for power law or First Sutherland Constant 650.d0 ! Tref [K] - Reference temperature for power or Sutherland law -0.6861d0 ! < 0: exponent for power law, > 0: Second Sutherland Constant, = 0: viscosity filled with one (non-dim only) 0.660d0 ! Prandtl number