Effects of Periodic Incoming Wakes on the Aerodynamics of a High-Speed Low-Pressure Turbine Cascade

The influence of unsteady wakes incoming from the upstream stages is high relevance in modern high-speed, low-pressure turbines (LPT) operating at transonic exit Mach numbers and low Reynolds for their potential to trigger transition separation boundary layer on blade suction side. aim this paper experimental characterization 2D aerodynamics a high-speed LPT cascade number number. A detailed analysis status flow along under investigation its impact profile loss are presented range 0.70 0.95 70k 120k steady inflow conditions. Tests were conducted on- off-design engine realistic conditions VKI S-1/C wind tunnel SPLEEN C1 cascade. an row have been replicated using set rotating bars, which shed engine-representative reduced frequency (f+=0.95) coefficient (Φ=0.80). densely instrumented traversable blades used sample surface pressure distributions. development layers side examined through quasi-wall shear stress obtained with surface-mounted hot-film sensors. Wake traverses carried out downstream miniaturized L-shaped five-hole probe characterize losses. introduction periodic promotes variations topology over blade. effect bubble shown depend At numbers, determine reduction size bubble; contrast, not registered as increases. Consistently, dependence wake demonstrated.