| Popis: |
This Phase I Analysis Report presents the results of stress analyses, heat transfer analyses, and a vendor product survey and evaluation. The analytical stress calculations which included the effects of PG anisotropy, creep, and growth showed the structural feasibility of fabricating and firing free standing PG thrust chambers up to 5000 pounds thrust. Operation at chamber pressures up to 300 psia appears feasible. However, the effects of growth and creep at high operating temperatures may be critical and experimental data are required to establish valid design criteria. The heat transfer studies investigated the transient and steady state temperature distributions within the PG chambers for each of the propellants considered. Five pyrolytic graphite vendors supplied samples of their pyrolytic graphite products in the form of free standing, thin walled tubes 2 inches in diameter and 4 inches long. A total of 78 tubes was evaluated by burst testing in order to evaluate their structural capability. The critical effect of nodule size on maximum tube strength was confirmed. Maximum tube strengths were achieved with boron alloying and with regenerative microstructure. A burst pressure of 1000 psig appears to be a reasonable target for currently available pyrolytic graphite at room temperature. |
