Effects Of Variable Geometry On Turbine Stage Performance

Due to the complexity of the gas turbine working environment, it is often necessary tochange working conditions, so the variable geometry technology has been applied in a widerange. Relative to the fixed geometry engine, gas turbine variable geometry technologyimprove the working conditions effectivly in the non-design conditions, the gas turbine tobetter match the performance between the various components. This article focuses bychanging the first stage blades of a turbine stator blade installation angle of the turbinevariable geometry technology research. Adjustable guide vane mechanism and the drive shaftbodies in the process of using variable turbine geometry technology typically causes the bladetip portion of a certain gap, caused by the changes, the current status of the end portion offluid flow around and leakage phenomenon such losses turbine efficiency will have a greaterimpact. Therefore, the study transduction leaves the drive shaft institutions in varyinggeometric conditions on flow-field is the study of how to reduce the impact of the loss ofturbine efficiency, has a very important value and significance.First, from the point of view of the turbine blade design to complete the full radialequilibrium equation and simple radial equilibrium equation as a starting point leaves the ringdesign method, alpha1angle design, controlled vortex design methods and the pressurecontrollable vortex blade design theoretical methods. Comparative study showed that in leafexport static and dynamic axial velocity, the absolute export flow angle outlet circulation anddegree of reaction presents a different distribution of the five different design methods, eachhaving advantages of different turbine blade design shortcomings and adaptability. On thebasis of analysis and research, we use a pressure controlled vortex blade design turbine bladedesign.Subsequent article for the first stage stator blade of the turbine guide vane mechanismcan be transferred, focusing on the flow field under three different scenarios, and thencomplete the analysis of turbine performance. Explores the factors that affect turbineefficiency, focusing on interpretation of the role played by the horizontal pressure gradient inthe gap flow loss and leakage vortex formation and development. Vanes as the research object,has compared the gap stationary blade gap stationary blade with drive shaft vanes three options parameter distribution. On the basis of the different options, and further study theimpact of the of vanes export parameter variation on the rotor blades. The initial studycompared three options under the rotor blade tip clearance leakage, one after another afteranalysis of the outlet flow angle of the vanes, rotor blades changes in the inlet flow angle, aseries of changes in the parameters of entropy cloud images.Finally, the turbine stator blade-6,-3,0,+3,+6degrees five kinds of different openingson the first level of the turbine of the numerical simulation. Contrast of pressure transductionleaves in the five case distribution, flow distribution and total pressure loss coefficientdistribution, in-depth to explore the similarities and differences of the different options understatic and dynamic distribution of the leaves of various parameters, analysis arrived at adifferent angle leakage vortex development The condition that the vanes can be transferredleakage vortex caused by the energy loss in the turbine changes.