AFT Application Topics
Specific Heat Ratio
The specific heat ratio of a gas (symbolized as gamma “γ” but also known as “k”) is commonly defined as the ratio of the specific heat of the gas at a constant pressure to its specific heat at a constant volume (see Equation 1).
Equation 1: Simplified Specific Heat Ratio Equation
However, the complete definition of the specific heat ratio, from Bejan, A., Advanced Engineering Thermodynamics, John Wiley & Sons, New York, NY, 1988, is shown in Equation 2 below:
Equation 2: Complete Specific Heat Ratio Equation*
In many cases, engineers use the simplified equation in their compressible flow calculations. While this is an appropriate assumption in the vast majority of cases, situations do arise in which it is necessary to use the complete definition.
AFT Arrow allows users to model their systems using both the simplified and the complete definition of the specific heat ratio.