### 1.5.3. Specific Heat Capacity

When the global option for Mixture Properties is set to `Non Ideal Mixture`, you can set the specific heat capacity for the mixture. The Specific Heat Type can be either `Constant Pressure` or `Constant Volume`. In addition to specific heat capacity, you also need to specify the specific enthalpy and the specific entropy.

CEL expressions may be used for defining the three parameters as functions of the mixture composition and the corresponding properties of the mixture components. The following quantities are available for use in the expressions:

- Specific Heat Capacity: pressure, temperature, component mass fractions, component mole fractions, component molar masses, component specific heat capacities

- Specific Enthalpy: pressure, temperature, component mass fractions, component mole fractions, component molar masses, component specific enthalpies

- Specific Entropy: pressure, temperature, component mass fractions, component mole fractions, component molar masses, component specific entropies

As an example, the text box below shows the CCL commands for defining a specific heat capacity for a mixture consisting of four components: H2, O2, H2O and N2. For demonstration purposes, the example resembles the ideal mixture rule.

    SPECIFIC HEAT CAPACITY:
      Option = Mixture Specific Heat Capacity
      Specific Heat Type = Constant Pressure
      Specific Heat Capacity = H2.Mass Fraction*H2.Cp + \
                               O2.Mass Fraction*O2.Cp + \
                               H2O.Mass Fraction*H2O.Cp + \
                               N2.Mass Fraction*N2.Cp
      Specific Enthalpy = H2.Mass Fraction*H2.Static Enthalpy + \
                          O2.Mass Fraction*O2.Static Enthalpy + \
                          H2O.Mass Fraction*H2O.Static Enthalpy + \
                          N2.Mass Fraction*N2.Static Enthalpy
      Specific Entropy  = H2.Mass Fraction*H2.Static Entropy + \
                          O2.Mass Fraction*O2.Static Entropy + \
                          H2O.Mass Fraction*H2O.Static Entropy + \
                          N2.Mass Fraction*N2.Static Entropy
    END

Release 18.2 - © ANSYS, Inc. All rights reserved.