RECENT ADVANCES IN SIMULATING UNSTEADY-FLOW PHENOMENA BROUGHT ABOUT BY PASSAGE OF SHOCK-WAVES IN A LINEAR TURBINE CASCADE

High-pressure-ratio turbines have flows dominated by shock structures that pass downstream into the next blade row in an unsteady fashion. R ecent numerical results have indicated that these unsteady shocks may significantly affect the aerodynamic and mechanical performance of tur bine blading. High cost and limited accessibility of turbine rotating equipment severely restrict the quantitative evaluation of the unstead y flowfield in that environment. Recently published results of the Vir ginia Tech transonic cascade facility indicate high integrity in simul ation of the steady-state flow phenomena. The facility has recently be en modified to study the unsteady effects of passing shock waves. Shoc k waves are generated by a shotgun blast upstream of the blade row. Sh adow graph photos and high-response pressure data are compared to prev iously published experimental and numerically predicted results. Plots are included that indicate large fluctuations in estimated blade lift and cascade loss.