Design method of endwall profiling based on Bezier curves

With the purpose to deeply research the effect of improving aerodynamic performance and flow field in turbine stator, and to preliminarily understand the influence on turbine stage performance caused by non-axisymmetric endwall, according to the basic principle of non-axisymmetric endwall profiling technology, a novel design method of non-axisymmetric endwall profiling was developed based on the Bezier curves in combination with trigonometric functions. This design method was applied to the hub of one high pressure (HP) turbine stator to construct six different non-axisymmetric endwalls by changing the amplitude values. Subsequently, the three-dimensional flow in original and profiled HP turbine stator were simulated in the condition of whole stage. The analysis results indicate that the appropriately profiled non-axisymmetric endwall can effectively reduce the flow losses in the stator passage and there is an optimum amplitude 6 mm, i. e. 10% span when applying this method to the hub of this stator. While the total pressure loss coefficient decreases by 0.94% thanks to the non-axisymmetric endwall, the interaction between stator and rotor is also affected as a consequence of the reduction in the stage performance.