Investigation On The Rotor Stator Interaction And The Aerodynamic Loads On The Impeller In Centrifugal Compressor With Variable Inlet Guide Vane Trailing-edge Blowing

As an important equipment,the centrifugal compressor has been widely used in many fields of national economy for transporting and increasing the pressure of gas.The impeller is the core part of a centrifugal compressor,as it suffers from the effect by of complex flow fields,such as the interaction between the guide vane wake and inlet flow distortion.These factors incur unsteady aerodynamic loads on the impeller,which is the main reason for impeller fatigue failure.The stator trailing edge blowing is an effective way to reduce the wake intensity,the aerodynamic loads on the impeller and the noise.Hence,it is significantly to investigate the flow field of trailing edge blowing,which leads to efficient and economical,safety and smooth operation of the centrifugal compressor.Combing the experiments and the numerical simulation,this paper investigates the aerodynamic loads distribution under the variable inlet guide vane(VIGV),radial inlet and guide vane trailing edge blowing.The main research contents and conclusions are divided into five aspects:1.A centrifugal compressor with VIGV is selected as the research object.The scaled VIGV with dual slot blowing construction is designed and investigated.The full circle VIGV experimental platform is built,and the bilinear interpolation calibration method based on polynomial fitting for seven holes probe is proposed,which increases the measurement accuracy.Compared with the experimental results,the numerical simulation is reliable for the subsequent research.2.The mechanism of the momentum less-wake caused by trailing edge blowing is studied.The blowing width and different blowing forms have been discussed by colparing the flow fields,such as velocity,mass flow,turbulence intensity and flow angle.Base on the theory,the experiments and the simulation results,the prediction model of blowing velocity under multi-variables with VIGV condition is constructed with the error less than 5%.3.The platform for rotor-stator interaction(RSI)simulation is built.Through the unsteady simulation,the mechanism of the RSI by VIGV wake are investigated.The results confirm that the trailing edge blowing is an effective way to reduce the wake intensity and the aerodynamic loads on the impeller significantly.4.The effective range of the trailing edge blowing under real compressor condition is investigated,and the impact of different wakes is verified.The structural design criterion of VIGV trailing edge blowing is proposed.A "C" shape self-induced blowing flow is found in the slot.It regulates the wake distribution at the VIGV trailing edge,and reduces the pure wake to weak wake,which further deceases the aerodynamic loads on the impeller.5.Taking a compressor with radial inlet as the research object,the inlet distortion caused by the radial inlet is studied.Based on the modal analysis and the RSI theory.guide vanes are added into the radial inlet.The arc shape guide vane improves the inlet distortion,and decreases the aerodynamic loads at rotational frequency.The trailing edge blowing is applied to the guide vane,which reduces the aerodynamic loads at impeller passing frequency.