A High-Speed Disk Rotor Rig Design for Tip Aerothermal Research

The relative casing motion can greatly vary the over-tip-leakage (OTL) flow structure and aerothermal performance. The existing tip experimental research facilities including stationary linear cascade, cascade rigs with low-speed moving belt, or high-speed rotor rigs are either not capable of reproducing the high relative casing Mach number or extremely expensive and still difficult for optical measurement. This paper presents a high-speed disk rotor design that can simulate the high casing relative speed. The unique feature of this rig design concept is that it enables full optical access of the tip surface under the engine-representative OTL flow condition. In this paper, the feasibility of the design concept is demonstrated and assessed by Reynolds-averaged Navier-Stokes computational fluid dynamics (RANS CFD) simulation, both in component level and in whole rig system level. First-of-its-kind experimental results of spatially resolved tip heat transfer coefficient distribution at high relative casing Mach number are reported. The disk rotor rig design demonstrated in this paper can also be useful for other tip leakage flow studies.