Optimization Of Blade Number Based On CFD For 9-26-8D Centrifugal Fan

Centrifugal fan is a widely used fluid machine,which is extremely important in the fields of national life and industrial production.Therefore,the optimization design of the centrifugal fan and the improvement of the fan have great significance in energy saving,loss reduction and noise reduction.In this paper,the internal flow field of 9-26-8D high-pressure centrifugal fan is analyzed by numerical simulation method,and its aerodynamic performance and characteristic parameters are studied.In order to improve the total pressure and efficiency of the fan,the number of blades of the centrifugal fan is optimized.The following work is mainly carried out and conclusions are drawn:This paper takes 9-26-8D centrifugal fan as the research object,introduces the basic structure and main performance parameters of the fan,and analyzes the energy loss that affects the working performance of the fan.Based on the semi-empirical formula of the number of centrifugal fan blades,the numerical simulation scheme of the centrifugal fan is determined.The original fan was modeled and meshed by the cooperative simulation software ANSYS Workbench.The original fan was numerically simulated under full working condition using FLUENT software.The feasibility of the numerical simulation scheme was determined by comparing the characteristic parameter tableof the fan.Find out the best operating point of the fan under the numerical simulation method is the speed of 2900 rpm and the flow rate of 2094700 m/h.The internal flow field static pressure,dynamic pressure,full pressure,speed and speed direction of the meridional surface and the rotary surface of the fan under the optimal working conditions are analyzed in an all-round way to understand the internal flow of the fan.According to the change of the number of blades,the fans with different number of blades were re-modeled.Under the conditions of maximum flow,minimum flow and optimal working conditions,the numerical simulation of seven different number of blades was carried out by orthogonal experiment.By comparing the total pressure and efficiency,a total law is obtained.As the number of blades increases,the total pressure also increases,and the efficiency increases first and then decreases.The number of 20 blades is selected as the optimal solution.Finally,the 20-blade number model is numerically simulated under full working conditions.After comparison with the original fan,the efficiency of the fan can be improved by up to 3.8% and the minimum by 0.3%.,Average efficiency can be increased by more than 1%?...