3-DIMENSIONAL NAVIER-STOKES ANALYSIS OF TIP CLEARANCE FLOW IN LINEAR TURBINE CASCADES

A three-dimensional viscous flow code was used to study the tip clearance flow in linear turbine cascades. Two test cases with detailed measurements were used for validation. The flow properties inside the tip gap, such as static pressure, velocity, and angle, were compared with the data. The blade loading at different span locations and the downstream flowfield properties, such as loss and angle, were also compared with the data. The clearance flow phenomena, such as leakage vortex, changing of loss distribution, and flow underturning, were predicted by the numerical code. This code not only can be used as an analysis tool to study tip clearance effects in real turbine blade rows but also can be used as a design tool to design the turbine components.