Effect Of Curvature Continuous Leading Edge On The Aerodynamic Performance In Compressor Static Blade

As one of the most important components of gas turbine,how to improve compressor performance is always the main research direction.The size of the leading edge of the blade is small,but the variation of its geometry will affect the distribution of the whole flow field.So reasonable optimization of the leading edge can effectively restrain the flow separation and improve the overall performance of the compressor.In this paper,the typical blade shape with DMU37 90%blade height is chosen as the research object,by programming with VS,the arc leading edge is designed into different curvature leading edges.Then the numerical research is carried out by the CFX numerical software.Through the analysis of the parameters of the total pressure loss coefficient,the suction peak and the leading edge flow line distribution,compared the flow field performance of the circular leading edge and the curvature continuous leading edge,then seeking the optimal continuous curvature design scheme.First,used Numeca software to divide the grid and carried out the grid independent verification,then the best turbulence model is selected on the basis of experimental results in order to ensure the accuracy of numerical results.The numerical analysis of the flow field of the prototype cascade shows that under the same incidence,the flow loss will aoso increases when the Mach numberincreases,and the upper and lower end wall is the main area.Under the same Mach number,the separation bubble appears on the side of the pressure surface in-6°incidence and disappear in-3°incidence,then it will appears on the side of the suction surface in 0°incidence,and the degree of separation increases will increases with the further increasing of the incidence.Then,adopted a method to design continuous curvature.After the circular leading edge is designed as three different curvature continuous leading edges,analyzed and compared the flow field with the circular leadingt edge under different working conditions.The results show that when the total pressure loss coefficient of the circular leading edge scheme is small,the curvature continuous design is not good for reducing the total pressure loss coefficient.The greater the total pressure loss coefficient of the(?)circular leading edge scheme,the more obvious the reduction effect of the curvature continuous design on the total pressure loss coefficient;The smaller the incidence is,the better the curvature continuous design weakens the suction peak effect.At the same incidence,the deeper the connection point is chosen when designing,the better the weakening effect of curvature continuous front edge.When the circular leading edge separation bubble is small,the continuous curvature design can effectively reduce the separation bubble,then the curvature continuous leading edge with deeper connecting point can even completely eliminate the separation bubble,and the continuous curvature leading edge can still effectively restrain the separation bubble when the circular leading edge is separated.Finally,a continuous curvature continuous leading edge scheme with large curvature change in leading edge is added.The analysis shows that the total pressure loss coefficient of this scheme is larger than that of the best optimized 4.5r scheme and even larger than the prototype under some working conditions.But the effect of this scheme reducing the suction peak and reducing the effect of leading edge flow separation can compared with the 4.5r scheme.The comprehensive comparison analysis shows that there is an optimal location for the selection of connection points when the curvature continuous leading edge is designed.Even though the curvature continuous leading edge above this position can weaken the suction peak,it will increase the loss.