STEADY, ISENTROPIC FLOWS OF DENSE GASES

Steady isentropic flows of fluids in their dense gas regime are examined. It is shown that the Mach number may increase, rather than decrease, with density or pressure if the specific heats of the fluid are sufficiently large. Conditions are also reported under which isentropic expansions through converging-diverging nozzles are not possible, regardless of the imposed exit pressure. In such cases, the nozzle must be replaced with one having multiple throats. Applications to external transonic flows are briefly considered.