The perfect-gas assumption leads smoothly to Mach-number relations which are very convenient (and tabulated). This is not so for a real gas such as steam. To illustrate, let steam at T0 = 500°C and p0 = 2 MPa expand isentropically through a converging nozzle whose exit area is 10 cm2. Using the steam tables, find
(a) The exit pressure and
(b) The mass flow when the flow is sonic, or choked. What complicates the analysis?