The Calculation of Reheat and Expansion Efficiency: The Calculation of Reheat in Gases Expanding in Converging Passages by Temperature or Pressure Measurement only

For any convergent nozzle passing a compressible fluid and discharging against a pressure below the expanding power of the nozzle, there is a unique pressure and temperature distribution both of which depend upon the overall resistances to flow and the reheating effect incurred. By measurement of a single function of state along the flow path it is theoretically possible to calculate the reheat and expansion efficiency. The following analysis for one‐dimensional irrotational flow is an attempt to predict on a basis of theory the probable difficulties which would arise in practice and the accuracy to be expected. It is found that the pressure distribution is insensitive to reheat, but that the temperature distribution provides a fair indication.