A new method for calculating ducted flows

The present investigation is concerned with a new one-dimensional method for calculating steady flows in ducts, such as expansion nozzles, shock diffusers, or ejectors. The derivation of the flow equations is based on an explicit presentation of the force/momentum balance in the duct. Derivations for single-flow applications are considered and the case of the expansion nozzle is explored. The obtained results are compared with those provided by a procedure reported by Shapiro (1953), who uses the concept of influence coefficients to calculate flows in ducts. One of the advantages of the new method is that it does not become undetermined at Mach 1.