Experimental An Numerical Research On The Aerodynamic Characteristic Of A 1.5 Stage Axial Transonic Compressor

Modern axial compressor is developing to high load, high pressure ratio, and wide operating range direction. In the supersonic and transonic compressor, the pressure ratio is very high, the flow in the compressor is complex, and there is phenomenon of interaction between shock waves and boundary layer, passage vortex in the blade passage. So the research on axial transonic compressor is very important.This paper studies the one and a half stage transonic compressormodelling the F class gas turbine first stage, experimental and numerical approaches are the important methods. In the aspect of experimental study, measurement schemes include three subsystems, measuring system of the performance of compressor, stall and surge detection system, static pressure measuring system, including the casing static pressure distribution along the axial direction, and the static pressure in the rotor casing. In the aspect of numerical calculation, CFD computation is done in 2 aspects: the steady and unsteady numerical simulation. And analyzing flow condition and characteristic of the compressor is carried out in this paper.Experimental research shows that: the performance of the measurement system is reliable enough that it meets the requirement of the experimental study. Stall cell at 10000 rpm is measured in the leading rotor, and its speed in circumferential direction is about 0.67 times of the compressor rotate speed. The distribution of the casing static pressure along the axial direction shows that air is accelerated in IGV and the compression process ofair is mainly carried out in stage of compressor. Using BP neural grid method can reproduce the distribution of the rotor casing static pressure relatively better. The intensity of the TLV will increase with the decrease of the flow and the increase of the rotor speed. The time domain wave of un-steady pressure fluctuation was transformed into frequency spectral curves by Fast Fourier Transform. Peak value in dominant frequency shows that the fluctuation of static pressure mainly locates in the first half rotor, and this fluctuation increase with increase of the rotor speed and the increase of the flow.Numerical simulation shows that: via comparing the steady predicted results with the available experimental data, it turns out that this numerical approach can match the total performance map of the compressor well. This paper analyzes the flow characteristics of three typical performances, including the near chock point, near peak efficiency point, near stall point and studies the shock wave and flow separation in different passage. This paper studies the aerodynamic parameters alone the blade height changing with the flow condition. In the rotor, the tip leakage flow includes the tip leakage vortex(TLV) starting from leading of the rotor suction side, the tip leakage flow located middle of the rotor, impinging the neighboring blade, and the tip leakage flow located the trailing of the rotor. The intensity of the TLV will increase with the decrease of the flow and the increase of the tip gap of the rotor. Unsteady numerical simulation shows that the tip leakage flow propagates in circumferential direction against the rotor turning direction along the rotor blade row(referred to the relative frame), 2 times of blade passing speed.