Researches On Aerodynamic Noise Reduction Technology Of Centrifugal Fan

Noise has become one of the three major industrial pollution. As an important equipment in industrial,fan is becoming more and more get the attention of the people caused by its noise problem. people need low noise fan to used to reduce the noise interference in the work and learning environment anxiously. As an important type of fan, centrifugal fan is a focus in the study of noise reduction. In this paper, centrifugal fan producted by HuaWei company as analysis object, through the theoretical research, numerical simulation and experimental verification method, flow field and acoustic field characteristics of the centrifugal fan are analyzed, and put forward the corresponding aerodynamic noise optimization scheme, its concrete content includes:(1)Study on the working principle of the centrifugal fan, concentrated in two aspects mainly: flow field characteristics and acoustic field characteristics. Study the type of centrifugal fan and vocal mechanism of aerodynamic noise, analysis of the source of centrifugal fan noise and noise distribution characteristics. Using cylindrical disturbed flow and agitator model to study the influence of the turbulence model selection, near wall treatment, the activity field distribution and noise source selection on the simulation results, determine suitable simulation methods for centrifugal fan.(2)Analyzes HuaWei fan by using the SSPM method. Geometric modeling is obtained by reverse engineering modeling; The fluid computational domain of fan imply dividing grid strategy. Use Fluent software for simulation calculation, get the flow field and acoustic field data, comparing with the existing test data to verify the correctness of the simulation method.(3)Using the method of numerical simulation to study centrifugal fan active noise reduction, proposed anti-vortex ring noise reduction optimization scheme, analyzes the scheme PQ characteristics and the influence of the aerodynamic noise of the fan. Analysis PQ characteristics and the influence of the noise characteristic of guide-fluid plate scheme. Study the influence of commutation network on aerodynamic noise centrifugal fan, and the interpreter noise reduction mechanism. Summarizes PQ performance and noise value change of the different position of the fan impeller, find out the suitable position of the impeller Analyzes PQ characteristics and noise characteristics under different rotational speed fan, the speed optimization suggestions are put forward.(4)Study on passive noise reduction scheme, based on the characteristics of sound-absorbing material to reduce the high frequency noise and sound insulation materials to reduce low-frequency noise, proposed the noise reduction scheme that sporous sound absorption materials cooperated with sound insulation materials, using multiple acoustic chamber and the combination of sound absorption volute noise reduction scheme, and completes the design of the noise reduction scheme.(5)Designing, processing and testing of centrifugal fan flow, focus on flow field characteristics and acoustic field characteristics, summarize each optimization schemes for PQ performance and aerodynamic noise contribution, obtains the effective noise reduction scheme.