The Numerical Research Of Aerodynamic Design Technology Of Steam Turbine Stage Through-Flow Part

With the continuous development of turbomachinery industry, reducing production costs and improving aerodynamic performance has become a designer's goal. This paper researches on a high-pressure cylinder-type pressure steam turbine stage group introduced from Mitsubishi, the stress level group has lower blades and stages, higher single-stage pneumatic load, lower production costs and lower aerodynamic performance than the conventional stage. Studing features and ideas of the design, digesting and absorbing of its design has great reference and guidance. In particular, the group uses of design method of bend-twist joint for stator in the repeatable level, which improves aerodynamic performance of the flow path in high-pressure stage.In order to understand the idea of every blade design, using basic theory and calculating method of S2 through-flow design, this paper analyses, searches and summarizes from the design method for forming turbine blade. It also gives the general idea of S2 through-flow calculation, which is based on calculation schemas for unary form flow and primaried by selecting flow pattern and computing method through S2 stream surface,programmes to calculate the equation of Euler and NS and reviews the flowing of local blade profile.This paper extracts the theory of controlled vortex design and joint design of bending and torsion ,Multi-stage turbine and a high load of transonic turbine design should adopt the higher ideal enthalpy drop leaf along a parabolic law and control of output power against the intensity distribution along the blade height design method of combining, then applied the theory to the comparising analysis of the results for S2, with the help of comparising it with full three-dimensional calculation, shows the rationality of the experience parameter used in S2 Flow calculation.This paper uses FINE/TURBO for full three-dimensional calculation of the passage and analyze comparative mach number, static pressure distribution and other calculating results of the whole meridianplane, the conclusion is similar to the distribution showed by the result of S2 through-flow calculating method, it validates the reliability of this calculating method again. At last, this paper analyzes the parameters of flow field of the second and third stages, through calculating static pressure distribution, ultimate streamline of blade surface, distribution rule of lost energy along the blade height, then points out the advantages and disadvantages of controling secondary flow in stationary blades, flow separation and losses distribution regularities of the produced stage group.