# 4.4.4. Volume-Of-Fluid Material Properties

A volume-of-fluid simulation requires separate material models for the liquid and gas materials, and a top-level material model to tie them together. Any required reference values should be supplied in the top-level material, but the sub-materials can generally be any type (basic, Cantera, etc). In the finite element block, the top level material would be the one assigned to the blocks. Interface properties, such as surface tension, should be provided in the top-level material.

    BEGIN PROPERTY SPECIFICATION FOR FUEGO MATERIAL fluid_material
      VOF Gas Material = gas_material
      VOF Liquid Material = liquid_material

      INTERFACE_ABSORPTION = 1000
      SURFACE_TENSION = 0.073
      REFERENCE TEMPERATURE = 370.0
    END   PROPERTY SPECIFICATION FOR FUEGO MATERIAL fluid_material

    BEGIN PROPERTY SPECIFICATION FOR FUEGO MATERIAL gas_material
      density = "300/temperature"
      VISCOSITY = 1.98e-5
      SPECIFIC_HEAT = 1000
      THERMAL_CONDUCTIVITY = 0.025
      ENTHALPY = "1000*temperature"
      ABSORPTION = 0.1
    END   PROPERTY SPECIFICATION FOR FUEGO MATERIAL gas_material

    BEGIN PROPERTY SPECIFICATION FOR FUEGO MATERIAL liquid_material
      DENSITY = 1000
      VISCOSITY =  1e-3
      SPECIFIC_HEAT = 4184
      THERMAL_CONDUCTIVITY = 0.6
      ENTHALPY = "4184*temperature"
      ABSORPTION = 1.0
    END   PROPERTY SPECIFICATION FOR FUEGO MATERIAL liquid_material