Aerodynamic Spike Experiments on a Sphere in Supersonic Flow.
Abstract
In order to estimate the potential usefulness of an aerospike for reduction of reentry observables, preliminary tests were conducted to determine the effective body shape created by an aerodynamic spike on a hemisphere in supersonic flow. The tests were performed in a 200-kW air arc tunnel on a 1-in.-diam sphere with an internal forward-facing supersonic nozzle through which nitrous oxide gas was injected. The wind tunnel flow Mach number was 4.5 and the aerospike initial Mach number was 2.2. The aerospike nozzle exit diameter was 0.104 in. The mixing region of nitrous oxide gas and air was visible due to chemiluminescence, permitting photographic determination of the approximate effective body shape. Three characteristic regimes of aerospike behavior were observed, in which the effective body shape ahead of the hemisphere progressed from nearly-conical to nearly spherical. The maximum aerospike length in the nearly-conical body regime was one-half of the sphere diameter; this length was strongly dependent upon angle of attack beyond 3.5-deg angle of attack. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 1969
- Accession Number
- AD0854313
Entities
People
- William E. Welsh Jr.
Organizations
- The Aerospace Corporation