Accession Number : ADA299590

Title :   Thrust Vector Control of Rectangular Jets using Counterflow.

Descriptive Note : Final rept. 1 Feb 94-30 Apr 95,

Corporate Author : FLORIDA STATE UNIV TALLAHASSEE DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Krothapalli, A. ; Forliti, D. J.

PDF Url : ADA299590

Report Date : 07 JUL 1995

Pagination or Media Count : 135

Abstract : This research studied the flow generated by a rectangular convergent-divergent Mach 2 nozzle operated in a free jet and a counterflow thrust vectored configuration. Particle Image Velocimetry was used to obtain 2D velocity fields and total and static pressures were measured. In the free jet configuration, the nozzle was operated at ideal, over, and underexpanded conditions. The growth of shear layers was unaffected by shock cells for mildly off-design conditions. The thrust vector configuration is similar to an ejector, where suction is applied to one side of the jet. This creates a cross-stream pressure gradient resulting in a vectoring of the jet. The application of suction creates counterflow. This gives the jet a streamwise curvature, the destabilizing nature of which causes an increase in the growth of the non- suction side of the shear layer. The suction side shear layer experiences counterflow and both destabilizing and stabilizing curvature. It becomes thicker with suction, suggesting a self-excited state.The development of large scale structures when suction is applied gives further evidence of self-excitation. These structures cause enhanced mixing resulting in the cross-stream pressure gradient which leads to vectoring.

Descriptors :   *THRUST VECTOR CONTROL SYSTEMS, *CROSS FLOW, *CONVERGENT DIVERGENT NOZZLES, STABILIZATION, PRESSURE GRADIENTS, EXCITATION, SHOCK WAVES, BOUNDARY LAYER, FLOW VISUALIZATION, PRESSURE MEASUREMENT, COMPRESSIBLE FLOW, FLOW FIELDS, EXPANSION, MACH NUMBER, VELOCIMETERS, CONVECTION(HEAT TRANSFER), FREE STREAM, SUCTION, STATIC PRESSURE, STAGNATION TEMPERATURE, NOZZLE GAS FLOW, SCHLIEREN PHOTOGRAPHY, SHEAR FLOW, EXHAUST GASES, JET MIXING FLOW.

Subject Categories : Fluid Mechanics
      Rocket Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE