Research Of Model Optimization And Noise Control On A High Efficiency And Low Noise Of9-19Type Centrifugal Fan

Recently years, under the general trend of energy saving, the products which havehigh efficiency and low noise are much favored by the users and enterprises. This articleaimed at the problem of high noise and inefficient during the operation of the series9-19centrifugal fan which was used widely to expand research. The method combined withsimulation and test were used to on the impeller flow channel, volute flow channel and thewhole machine channel. The main factors of the noise and inefficiency had been analyzed,and the aerodynamic noise had been forecasted. This article aims to provide somereferences and basis for the study of energy efficiency and noise on centrifugal fan. themain works are as following:To analyze the internal flow field, come to the information of the flow field irrationalstructure, this article modeled the three-dimensional model and meshed the full flowchannel of the original forward curved centrifugal fan in considering the premise of theboundary layer, carried out numerical simulation on steady.For the aerodynamic noise, based on the steady calculation of the original fan, theFLUENT broadband noise model was used to analysis the turbulent noise of the fan.Taking the steady calculation as the foundation, the methods combined CFD and thethird acoustic software was used to analysis the amplitude and near field noise on theblade surface and the inner surface of the casing, the far field noise also had been got byusing numerical calculation and aerodynamic noise prediction. The accuracy of the noiseprediction was verified. According to the results of the noise prediction, analyzed themainly cause of the noise on the fan.According to the parameter of structure and performance, the existing performanceoptimization methods on centrifugal fan had been summarized. Combined the informationcome from the numerical simulation on the internal flow field of the original fan, thedesign modification of the centrifugal fan had been presented. By controlling the distribution of the average relative velocity in the impeller, the impeller blades had beenredesigned. Velocity distribution and design criteria were proposed based on the goal toweaken the structure of the jet-stream and secondary flow，control the flow loss. Afterforming the impeller, the volute is designed based on the impeller and finally create thewhole structural model of the centrifugal fan. Total pressure performance and efficiencyhad been predicted, and the design modification had been processed and tested to verifythe accuracy of the results.