Macroscopic Balance Model for Wave Rotors

A mathematical model for wave rotors is described. The wave processes that affect energy exchange within the rotor passages are modeled using one-dimensional gasdynamics. Macroscopic balances relate volume-averaged thermodynamic properties in the rotor passage control volume to the mass, momentum, and energy e uxes at the ports. Simple loss models are used to estimate entropy production in boundary layers and in separating e ows caused by blade-blockage, incidence, and the gradual opening and closing of rotor passages. The mathematical model provides a basis for designing port and rotor geometry, and for predicting design-point wave rotor performance. Model predictions are evaluated through comparisons with computational e uid dynamics calculations and three-port wave rotor experimental data. A fourport wave rotor design example is provided to demonstrate model applicability. The modeling approach is amenable to wave rotor optimization studies and rapid assessment of the tradeoffs associated with integrating wave rotors into gas turbine engine systems.