Experiment research on deep double squealer tip clearance leakage flow in linear turbine cascade

Experiment research was carried out on the tip clearance leakage flow characteristics of a linear turbine cascade in a low-speed wind tunnel with a series of deep double squealer at three kind of clearance. Theaerodynamics parameters were measured at outlet by a five-hole probe with high resolution and precisionto comparelyanalyse the flow characteristics and the distribution ofspan normalized loss, beyond that the Ink-Trace flow visualization was carried out on the cascade surface and the upper endwall. The results prove that the deep double squealer tip is applicable. Pressure side squealercutted near the trailing edge makes contributions to the decrease of leakage loss, while squealer cutted near the leading edge only have a little influence on the leading upper endwall locally. The whole passage vortex is mainly affected by the leakage flow. The cutted size match between near the leading and trailing edge will strongly inuencethe leakage loss.