| Most of the energy conversion depends on the impeller machinery,including solar,wind,water,electricity,heat,mechanical energy,etc..The impeller machinery has been widely used in many fields,such as chemical industry,agriculture,metallurgy,mine,pharmacy,electric power and so on.The impeller machinery is a very important kind of machinery is the fan.Relevant data show that the proportion of China’s energy consumption of fans accounted for about 12% of coal consumption.Axial fan has many advantages relative to the centrifugal fan,now,in many key industries and the key position,the centrifugal fan is gradually replaced by the axial fan.Therefore,it is of great significance to improve the research capacity and design level of the axial flow fan to save energy and protect the environment.In order to deeply understand the flow characteristics of the axial flow fan in the internal and external flow field,and put forward a reasonable method to optimize the axial flow fan to improve the axial flow fan aerodynamic performance,in this paper,two stage axial fan is studied,the method of numerical simulation is adopted,the influence of the fan structure on the aerodynamic performance and flow field distribution of the axial flow fan is studied in depth.The main research results are divided into the following three aspects:(1)The flow condition between the two stage axial fan is studied.The results show that the flow characteristics are mainly determined by the rotating parts.In other words,the first stage impeller has a greater influence on the flow between the impeller-vane stage,and the wake interference of the first stage impeller is stronger than the potential flow interference of guide vane;the second stage impeller has greater influence on the flow between the guide vane and the impeller stage.The interference of the potential flow of the second stage impeller is stronger than wake interference of the guide vane.(2)The influence of blade thickness on the aerodynamic performance of the fan is studied.The results show that the change of blade thickness has a great influence on the aerodynamic performance of the fan,In contrast,thin blade fan has better dynamic performance,but thickblades more stable working range;the change of blade thickness mainly changes the flow condition of leading edge and the pressure distribution on the blade surface.(3)Taking the blade installation angle in each section as the optimization parameters,the axial impeller was optimized by the orthogonal test optimization,the aerodynamic performance of impeller after optimized is improved.The entire flow interval,static pressure,total pressure,efficiency has greatly improved.In the design flow point,the total pressure increased by 16.1pa,the relative increment was 7%,the static pressure increased by 12.5pa,the relative increment was 20%,the efficiency increased by 2.38%,the relative increment was 4.6%.Moreover,it is found that the installation angle of the section near the tip has a great effect on the impeller’s total pressure,and the angle of the section near the blade root has a great effect on the impeller efficiency. |
