Hypersonic Nozzle/Afterbody Performance at Low Mach Numbers
Abstract
The propulsion system for an airbreathing vehicle that operates over a wide Mach number range, subsonic to hypersonic speeds, must be highly integrated into the airframe. The most promising design concept for hypersonic speeds is an airframe-integrated supersonic combustion ramjet (scramjet) which blends aircraft forebody and afterbody functions in combination with the engine (combustors) modules. The low speed performance of a generic 2-D hypersonic nozzle/afterbody configuration was studied experimentally. Wind tunnel tests were conducted at simulated flight Mach numbers of 0.6, 0.8, 1.9, and 3.0, in a Two-Foot Trisonic Gasdynamics Facility (TGF). Parametrics included four cowl configurations and simulated propulsion variations with high pressure, cold (ambient temperature) air. The exhaust flow characteristics, the pressure distributions, pressure coefficients, and pressure drags, were determined. The nozzle/afterbody exhaust flows were overexpanded for all of the configurations and conditions, and produced a pressure drag (thrust loss). The exhaust flow characteristics of the subsonic and supersonic flight Mach numbers were different. The subsonic condition resulted in higher pressure drag levels than for the supersonic conditions. The subsonic pressure drag levels increased with increased with increasing nozzle pressure ratios (NPR), while for the supersonic conditions, the pressure drag levels wer nearly constant or decreased with increasing NPR. Theses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1989
- Accession Number
- ADA216223
Entities
People
- Robert B. Cochran
Organizations
- Air Force Institute of Technology