.. _gas_const_sec: Gas constant value properties ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ An example to define a gas with constant properties is given below: :: EOS GAS SURFACE_DENSITY 1.2 kg/m^3 DENSITY CONSTANT 200.00d0 kg/m^3 ENTHALPY CONSTANT 1.8890d0 J/kmol VISCOSITY CONSTANT 0.03 cP END The units are optional, if not entered they will take the following defaults: * density units : :math:`kg/m^3` * enthalpy units : :math:`J/k\mbox{mol}` * viscosity units : :math:`Pa.s`