Numerical Simulation Of Aerodynamic Performance Of The Compressor's Typical Stages

As an important component of gas turbine, compressor plays a decisive role on the efficiency and power of gas turbine. Modern high-power gas turbine sets higher requirements on performance of compressor, such as high pressure ratio, high speed, high efficiency, but requires high reliability, long life and low weight.Based on the comprehensive research on simulation of aerodynamic performance of axial multistage compressor at home and abroad, the current developing status of numerical simulation of axial multistage compressor was reviewed. This paper gave a brief introduction about CFD chief characters and application in our country at present.In order to study the aerodynamic performance and configuration of axial multistage compressor, Numeca was used to carry out three-dimensional numerical simulation at No.14, 15, 16 stage of the multi-stage axial compressor. The meshes were generated by IGG, and used the single equation Spalart-Alimaras model to numerically simulate three stages of the compressor in FINE.Through three-dimensional numerical simulation of three stages of the axial compressor, total performance analysis for the stages of compressor was carried out firstly; analyzed blade design feature through studied profile static pressure, profile limit streamline, as well as the entropy contours on S3 section in three compressor operating conditions: design condition, surge condition, and choking condition.The three stages of compressor were studied by unsteady numerical solution of Harmonic method which applied for multi-stage axial turbo machinery. The unsteady flow field of the 14, 15, 16 stage was analyzed. The interference between the blades under unsteady condition and periodicity changes of the aerodynamic loads on blade surface were studied by contrast entropy and pressure in a cycle. This paper calculated aerodynamic load on each blade, analyzed the fluctuations and amplitude of the changes of aerodynamic force, aerodynamic torque and aerodynamic angle in different times in a cycle.The result showed that with the increase of the outlet pressure, the flow got more complex. Because of large negative incidence in inlet the of stator , rotor and stator matching should be improved in design. The flow of the end-wall deviated from the design condition because of the role of viscous friction and flow of the previous stage accumulation, so total performance could be improved by better match of flow angle between stages. Pressure fluctuations induced by the wake and the potential flow would clearly reflect in unsteady fluctuations of the aerodynamic load on the blade.