The Mach number, Ma, is the velocity of the gas divided by the velocity of the sound in the gas and can be expressed as:
The exit Mach number for compressible isothermal fluid has been shown to be Ma ≠ 1, but , where k is the ratio of the fluid-specific heat capacitites at constant pressure to that at constant volume. Table 4-23 shows the k values for some common gases. The following cases are such:
Case 3 is produced under certain operating conditions ...