Simulation And Optimization Of Fan And Impeller Flow Field Based On CFD Analysis

This research mainly focuses on analysis and optimization of two rotating impellers, which include an axial fan and a centrifugal impeller. Working principles of the two objects are similar, and the two objects both work inside fluid and push fluid through rotation of blades. The fan operates in the air while the impeller works in the liquid, which is the only variation between the two objects.The first object is an axial fan working inside the refrigerator, which plays the role of increasing air circulation inside the cooling chamber. The second object is an impeller of a pump, which is used to drain sewage out of the washing machine. This paper launches work according to these two objects respectively as follows.For research concerning the axial fan, an experimental setup is built based on working environment of the fan, then CFD model of the flow field is built according to the experimental bench. Experiments and CFD simulations are taken simultaneously to analyze features of the prototype fan. Optimum proposals are proposed from several aspects:blade number, blade sweep direction, blade installation angle and blade section shape. Results show that optimization of those aspects previously mentioned can improve efficiency of the fan. The final optimum fan realizes a 5.8% flow rate lift of the prototype fan with the same magnitude of power.For work concerning analysis and optimization of the pump impeller, experimental setup is built according to working environment of pump inside the washing machine at first. Meanwhile, simulation model is built to analyze flow field of the pumping system according to the experiment setup. Through comparison between experiment and simulation results, reliability of the simulation is ensured. The comparison also offers guidance for optimization proposal. Optimization proposal makes improvements on blade height and blade installation angle. Increasing height of the impeller advances highest efficiency point of the pump to actual working condition of the washing machine. Adapting installation angle of the blades makes the flow field distribution more uniform. Final result shows that the new impeller realizes a 6.62% promotion of the flow rate and 4.16% increase of the efficiency on the original impeller.Through analyses and optimizations of two rotating blades working inside two different fluids, the present study systematically summarizes main aspects influencing performance of the blades and the main direction for optimization, which can provide reference for future research on rotating blades.