Interferometric study of unsteady passing shock flow in a turbine cascade

To further advance the state of the art in axial turbomachinery, a better u nderstanding of unsteady phenomena within transonic turbines (including pot ential flow interaction, wake passing, and shock-wave passing) is required, Recently, the transonic turbine cascade facility at Virginia Polytechnic I nstitute and State University was modified to allow the study of unsteady p assing shock flow. The steady interferometric system in place was updated t o allow for a time-resolved, quantitative study of the density field produc ed by a single shock passing event. Variations in both the cascade inflow a nd flow through the transonic blade passages were quantized during the shoc k passage. The full density field in the cascade is presented at six discre te time intervals. A significant rise in the flow density, both upstream an d on the suction side of the blade passage, was noted.