Performance Optimization of X3R: A New Reflected Shock Tunnel Mode for the X3 Expansion Tube

Abstract

Availability of reflected shock tunnels capable of testing large-scale models and producing long-duration test flows is currently limited. The X3R free-piston reflected shock tunnel is in the final stages of development as an alternate operating mode of the pre-existing X3 expansion tube at The University of Queensland. A set of analytical and numerical procedures have been developed to aid in optimization of new operating conditions. This paper summarizes the condition development process and provides details of three candidate Mach 7 operating conditions theoretically capable of generating at least 10 ms of test time for full-scale scramjet engine testing. The facility’s atypical geometry, arising from its original design as an expansion tube, and the required compromises made during condition development are discussed.