Accession Number : ADA336232

Title :   Time Accurate Computation of Unsteady Hypersonic Inlet Flows with a Dynamic Flow Adaptive Mesh.

Descriptive Note : Final rept. 15 Apr 94-14 Nov 97,

Corporate Author : NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MECHANICAL AND AEROSPACE ENGINEERING

Personal Author(s) : McRae, D. S. ; Neaves, Michael

PDF Url : ADA336232

Report Date : 13 JAN 1998

Pagination or Media Count : 38

Abstract : Completed research is reported for an dynamic numerical investigation of unsteady flow in supersonic and hypersonic aircraft inlets. An explicit dynamic solution adaptive mesh computational code was further developed and used to obtain dynamic solutions for an axisymmetric mixed compression inlet and a generic dual mode scramjet inlet isolator diffuser combination. To improve robustness, an existing implicit code was modified for time accuracy and the solution adaptive mesh algorithm was installed. The inlet unstart phenomenon was simulated through perturbation of freestream and downstream conditions (axisymmetric inlet) and through downstream throttling for the dual mode 3-D configuration. Axisymmetric unstart could be induced by a 10% freestream temperature increase or a 5% backpressure increase. Comparison of the results with experiment, where available, indicate that stability margins assessed through inviscid design or quasi-steady experiment may need revision when dynamics are considered. Conclusions are drawn concerning specifics of the flow phenomena and directions for future research are suggested. Lack of highly resolved dynamic experimental data is a pacing item and will prevent full verification of future work.

Descriptors :   *COMPUTATIONAL FLUID DYNAMICS, *JET ENGINE INLETS, *HYPERSONIC FLOW, ALGORITHMS, THROTTLING, PERTURBATIONS, UNSTEADY FLOW, INVISCID FLOW, FREE STREAM, SUPERSONIC INLETS, THREE DIMENSIONAL FLOW, AXISYMMETRIC FLOW.

Subject Categories : Fluid Mechanics
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE