A complex
flow prevails at the tip gap between the rotating blade tip
and the stationary shroud.The leakage flow with a high
velocity will impinge on the blade tip.As the hot gas leaks
through the tip clearance from the pressure side to the
suction side,the blade tips also may be broken because the
thin boundary layer and the associated high heat transfer
coefficient. A squealer is essentially a recessed cavity on the
blade tip