FREE STANDING PYROLYTIC GRAPHITE THRUST CHAMBERS FOR SPACE OPERATION AND ATTITUDE CONTROL. PHASE II: SMALL SCALE TESTING
Abstract
This Phase II report presents the results of a test firing evaluation of small scale (100-pound thrust), free standing, pyrolytic graphite(PG) thrust chambers for application to high energy upper stage and attitude control liquid rocket engines. Propellant combinations used in the test firings were LF2/ BA1014, LF2/GH2, and N2O4/0.5N2H4-0.5UDMH. The results of large scale (1000- pound thrust) test firings will be reported in a future final (Phase III) report. The results of previous analyses and material studies conducted prior to the small scale test firings are presented in the Phase I report. Forty- seven pyrolytic graphite thrust chambers were fabricated in a variety of configurations to evaluate design concepts developed under the Phase I work. During test firings with N2O4/0.5N2H4-0.5UDMH, eleven sea level PG chambers were tested at 100 psia chamber pressure, with a maximum accumulated duration on one chamber of 300 seconds, including one run of 200 seconds. During some of these tests, the PG chamber wall was film cooled by fuel supplied from orifices in the injector. The erosion rate at the throat during the 200 second run was less than 0.08 mil/sec. The accumulated firing time with sea level chambers was 1022 seconds. Three altitude PG chambers with 40:1 expansion nozzles each failed after about 16 seconds of test firing with N2O4/0.5N2H4-0.5UDMH. The probable cause of failure was the combined effects of thermal stresses and axial residual stresses on the outside of the throat.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1967
- Accession Number
- AD0382057
Entities
People
- C. D. Coulbert
- J. G. Campbell
- M. L. Haas