Numerical Simulation And Performance Analysis On Centrifugal Fans

The centrifugal fan,an important turbomachinery,has been extensively applied in industrial production.Meanwhile,the centrifugal fan is also a member of main power consumption equipment in industrial production.At present,the research and develop of centrifugal fan is mainly by the means of experiments in domestic factories,by comparing with a large number of experimental data to get relatively better results.Although experimental methods in most cases can meet the production requirements,the experiment process is inevitably accompanied by amount of the loss of human and financial resources,long cycle of designing and developing of new product,and many other adverse factors.Using advanced numerical simulation method t can solve the above problem.In this paper,we carried the numerical simulation on centrifugal fan of a ventilation equipment company in zhejiang province with the optimization goal of static pressure and the efficiency,by using the Gridgen and Ansys CFX numerical simulation software.In the second chapter,the experimental study of centrifugal fan was introduced.Firstly,the working principle and the basic parameters of centrifugal fan were introduced.Then,the experimental study of centrifugal fan was performed with the help of the company's fan experimental platform,and a curve of fan performance,under the condition of experiment,was obtained after the experimental data analyzed.The third chapter is mainly about the research of centrifugal fan numerical simulation.At first,the basic principle of numerical simulation,the conservation equation,turbulence model and the mesh generation technology were introduced.Then,using Solidworks and Gridgen software,three-dimensional solid model centrifugal fan and full 3-D mesh model were established.Boundary conditions was set up and solved by Ansys CFX.The results of numerical simulation were analyzed in the fourth chapter.First of all,SST turbulence was selected as a more suitable model for this centrifugal fan by comparing the results of numerical simulation and experiments.Next,curves of flow static pressure and flow efficiency of centrifugal fan were drew under the numerical simulation.Through analyzing static nephogram and velocity contours under the cases of fixed conditions and variable condition,we could analyze the internal flow velocity contours.Studies of the effects of volume loss on centrifugal fan properties are showed in the fifth chapter.We optimized the impeller radial clearance “?” and the depth of the end of current collector stretching into the impeller “ l ”,which can affect the internal leakage.The results showed that the centrifugal fan not only has higher static pressure efficiency,but also has wider range of operating conditions,when ?-4mm and l-25mm .After optimization,the static pressure increased by 49.2 Pa and the efficiency increased by 2.5% under the rated conditions of the centrifugal fan(3.15 kg/s).The sixth chapter summarized the full text and showed work prospect.