Structural Parameter Optimization Of Low-noise Amplitude Fans For Rail Transit

The disturbance flow fan is a special fan for rail transit bus,which has the characteristics of uniform air supply and low noise.With the increasing demand and requirements of fan equipment,high efficiency,low noise and engineering practicability of disturbance flow flow fan become the main research objectives.Aiming at the comprehensive performance improvement of the disturbance flow fan for rail transit passenger cars,this paper puts forward a variety of impeller,hood structure parameters,and dynamic disturbance frequency based on different indexes,and optimizes the structure parameters of the disturbance flow fan through the combination of numerical calculation and experiment.The steady flow field with different blade number,camber angle,thickness,and end radius was simulated,and the total pressure efficiency,impeller efficiency,and static pressure velocity nephogram with different impeller parameters were analyzed and compared.Based on the research of steady flow field,the influence of bionic blade on aerodynamic performance and noise of amplitude flow fan is studied.The flow field and discrete noise in the blade area of prototype fan and bionic fan,and the broadband noise of hood are simulated and compared;combined with the actual project,the dynamic disturbance frequency optimization of disturbance flow fan is carried out.The difference of each index between the working condition with or without the loading of the disturbance flow fan and the working condition with different frequency disturbance field functions is compared and analyzed.The results show that the impeller structure parameters are the sensitive parameters affecting the performance of the fan,and are the key factors affecting the internal flow characteristics of the fan.The primary and secondary order of the influence of the hood structure parameters on the air volume and total pressure efficiency is the outlet width,the right hood radius,and the left hood radius.The bionic blade in this paper can improve the performance of the fan,reduce the noise effectively,and provide a reference for the selection and design of the impeller airfoil of the fan.After loading disturbance flow fan,the thermal comfort is better,and the dynamic disturbance frequency is lower,which is closer to the natural wind.Through the analysis and comparison of the research results,the structure of the high efficiency and low noise disturbance flow fan is summarized,and the dynamic disturbance frequency products in line with the actual engineering are proposed.The results can be used to improve the series products of disturbance flow fans in the rail transit passenger car system.