High-Pressure Rocket Engine Turnaround Duct Computational Fluid Dynamics Analysis,
PRATT AND WHITNEY AIRCRAFT GROUP WEST PALM BEACH FL
Pagination or Media Count:
Current and projected high-pressure, staged-combustion rocket engine designs, such as the XLR129 and SSME, have introduced a type of turnaround duct flowpath wherein the turnaround is accompanied by an increase in mean radius and a decrease in fluid velocity through a subsequent diffuser. This turnaround duct flowpath is needed in the rocket engine to conduct high-pressure turbopump turbine discharge gases toward the main injector while maintaining a compact turbomachinery and powerhead flowpath. Current experience in the SSME shows that this type of turnaround duct can experience flow separation with an attendant increase in flow turbulence levels. A version of the TEACH code developed by at Pratt and Whitney Engineering Division has been used to analyzed three representative turnaround duct configurations. One configuration is similar to the current SSME high-pressure fuel turbopump turnaround duct and the other two are P and W-designed configurations being studied under NASA Contract, Space Shuttle Engine Study. In addition to overall configurational differences, the study included the effects of fluid properties, inlet velocity flowfields, solution grid mesh size, and numerical solution algorithm upon calculated flow. Results include flow streamline comparisons, velocity profiles, and calculated total pressure losses. The results showed that turnaround ducts of the type studied can exhibit separation but that appropriately designed turnaround ducts can be made to function without suffering from internal flow separation.