Optimization And Test On Aerodynamic Performance Of Marine Steam Turbine Blade

Marine turbine is generally composed of two parts of the high-pressure and the low pressure turbine.Control its through-flow part of the blade is an important means to improve marine turbine efficiency.In order to effectively improve the efficiency of the marine turbine,it is necessary for the different characteristics of the high-pressure turbine and the low pressure turbine blade structure,used the appropriate method optimization and developed a new high-pressure turbine and the low pressure turbine blade profile,reduce the aerodynamic losses.Therefore,by the method of experiment and numerical simulation,the design of a new marine high-pressure turbine and the low pressure turbine blade profile and reduce the loss of pneumatic mechanism in-depth research.The main work of this paper can be summarized in the following four parts:In the first part,we improved the high pressure turbine of a marine eighth and ninth stage stationary blade,and changed the two prototype stationary blade which is uniform loaded to the aft loading blade by optimized.Do cascade aerodynamic performance test at 50%blade height of both prototype and remodel type.By the test,it can be seen that the optimized aft loading baldes can shorten the length of the segment of the suction side of the exports adverse pressure gradient,thus reducing the adverse pressure gradient value,and increase the angle of adaptability.Optimized aft loading blades can increase the basis pressure of wake flow,and also reduce the width of the wake flow.Different outlet Mach number and the angle of the experimental results showed that under the experimental conditions in the exit,Mach number is less than the critical Mach number,and the modification of the airfoil losses lower than the prototype.In the second part,we use a marine high pressure steam turbine level to improve the efficiency as the research object.By studied of final three stationary blade prototype and optimization of improved blade,we found the prototype high flow loss due to:the inner and outer ends strong lateral secondary flow near the wall and the stationary blade outer end wall imports meridian line sudden expansion caused boundary layer flow separation.The applications optimized design after loading the pneumatic vane able after the load further shift,this can be reduced both the inner and outer end wall of the first half of the horizontal pressure gradient flow path,and reduces both ends of the wall near the lateral secondary flow loss,but also can improve the entire blade the degree of expansion of the high-flow channel within the vapor stream,reducing the high total pressure loss in the entire blade.Also found that the final three stages to optimize the modification and the outer end wall the meridional repair type match,in order to more substantial in many conditions to reduce the final three flow loss.In the third part,we do improved research to the low-pressure steam turbine last stage and the final stage moving blade of a Marine.Prototype final two blades are straight blade,and the blade type is aft loading.After Improvement of the two rotor blades straight blade to optimize the design into a twisted blade,again leaves the suction side of the minimum pressure point further towards the rear and on both ends of the blade as much as possible after loading,matching of both cylindrical outer the end wall.Found optimization of rotor blades annular cascade experimental study of static aerodynamic performance.The results showed that:after optimized and improved,weakening the two cascade end wall region of the lateral pressure gradient,reduced outer end wall transverse secondary flow losses,reduce the blade aerodynamic losses.In the fourth part,we used a Marine low pressure turbine last stage and the final stage two as the research object.The application of experimental developed a new low pressure turbine moving blade gate while studying design corresponding new static blade gate,the prototypetwo and optimization studies after the end of the low pressure turbine design improved low pressure turbine end of two numerical simulation study.Numerical Simulation Study found through a number of options:optimization study program the weakened secondary flow loss,reducing the eddy current losses of the outer end wall of the flow separation,reasonable the static vane match design,weaken the positive angle of attack of the adverse influence the overall efficiency of the two than the prototype program has improved significantly.The research of marine high-pressure turbine and the low pressure turbine control blade loss is given in this paper,and we hoped to improve the structure of the unit efficiency design improvements to provide a reference to the improved marine turbine.