Pressure surface separations in low-pressure turbines-Part 1: Midspan behavior

Abstract

This paper describes an investigation into the behavior of the pressure surface separation at midspan in a linear cascade. It is found that the pressure surface separation can be a significant contributor to the profile loss of a thin, solid, low-pressure turbine blade that is typical of current engine designs. Numerical predictions are first used to study the inviscid behavior of the blade. These show a strong incidence dependence around the leading edge of the profile. Experiments then show clearly that all characteristics of the pressure surface separation are controlled primarily by the incidence. It is also shown that the effects of wake passing, freestream turbulence and Reynolds numbe..