Research On Matching Characteristics Of Two-stage Axial Compressor Components

The multi-stage axial compressor is widely used in the fields of electric power,chemical industry,metallurgy,ship and aviation due to its aerodynamic characteristics of large flow rate and high-pressure ratio.The performance of multi-stage axial compressor can be affected by the matching characteristics of upstream components,downstream components and internal components of the compressor during operation,so it is necessary to study the matching characteristics of two-stage axial compressor components.In the paper,an industrial two-stage axial compressor was selected as the research object,and the performance of multi-stage axial compressor under the influence of variable stator vane,upstream 90-degree bend and downstream tapered tube outlet was studied by numerical simulation and experiment testing.The CFD flow passage model was set up for the two-stage axial compressor firstly.The performance of the compressor was obtained with numerical method,and the results were consistent with experiments,the simulation method applied in the paper was verified for subsequent analysis.The installation angle of inlet guide vane,first stator and second stator of the compressor were adjusted respectively,the performance and internal flow field of the compressor were obtained correspondingly.With the analysis on the performance variation of the compressor under the effect of variable stator vane,the blade arrangement of compressor with strong through-flow capability,high pressure and high efficiency was obtained.Based on the analysis of the matching characteristics of variable stator vane,the blade arrangement of compressor with highest efficiency was selected,and the matching characteristics of upstream 90-degree bend of the compressor were studied then.With numerical method and experiment testing,the flow field inside 90-degree bend was analyzed,the non-uniform outflow of bend led to the complicated distortion at the entrance of the compressor.With full passage simulation,the performance deterioration of the compressor under the effect of upstream 90-degree bend was found,it was related with the length of bend outlet extension.Compared with the flow field in the compressor under uniform inlet condition,the propagation characteristics of inlet distortion induced by 90-dergree bend along streamwise direction were obtained.Due to the high consumption of simulation resource by using full passage simulation method,a simplified numerical method with single passage model and unsteady simulation was proposed,the propagation characteristics of inlet distortion and the variation of the compressor performance were found as similar with full passage simulation results,while the simulation cost was significantly reduced.After the analysis on the matching characteristics of upstream component,the matching characteristics of downstream tapered pipe outlet were studied.Affected by the downstream tapered pipe outlet,the flow direction of the compressor outlet was changed,the flow loss was increased then,and the overall performance of the compressor was deteriorated correspondingly.With the analysis on the performance matching of multi-stage axial compressor under the influence of variable stator vane,upstream 90-degree bend and downstream tapered tube outlet,the performance adjustment of industrial multi-stage axial compressor during operation can be guided,and the ideas for the design of high performance multi-stage axial compressor can be provided.