ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

5aNS8. Sound due to flow through a nozzle with time-dependent throat area.

Paul R. Moran

David Swanson

Acoust. Program, Appl. Res. Lab., Penn State Univ., P.O. Box 30, State College, PA 16804

An unsteady compressible Euler code was developed for flow through a nozzle. Method of characteristic boundary conditions were used to permit the unsteady pressure to be nonzero downstream of the exit boundary. The flow is perturbed by modulating the cross-sectional area in the midsection of the nozzle. The far-field unsteady pressure was determined for both steady and unsteady inlet velocities and compared to experimental results.