| The cooling fan is the key component which plays the role of heat dissipation,cooling and energy conversion in the motor,the flow of the internal flow field directly reflects the working performance of the fan.The cooling fans on the different motors have a unique design for the structure according to the workplace.The fan model can be obtained directly by using reverse engineering,and improved or optimized on the basis of the original fan,shortening greatly the production cycle of the fan.At present,there are few studies on radial straight blades.The high speed motor cooling fan in the electric torque wrench is taken as the research object,the fan surface was reconstructed by reverse engineering,then the flow characteristics of the inverted fan model were analyzed by hydrodynamics and verified by experiments,the main contents are as follows:According to the point cloud data that cannot be scanned in the scanning process,the local holes were repaired according to the uniform distribution of the fan structure and the curvature of the surrounding mesh,the reconstructed model was evaluated accurately and finally the model reconstruction of the cooling fan was completed.The cooling fan test was designed according to GB/T1236-2017,and the internal flow rate of the pipe was adjusted through the throttle plate,whose error would affect the measurement results.Therefore,the structure of the porous throttle plate was designed and tested according to GB/T2624-2006,and the flow field of the radial straight blade was analyzed comprehensively.which provides reference for the subsequent experimental study of radial straight blade.Using FLUENT to simulate and calculate the flow field of the cooling fan,and were compared with the experimental results,it is found that the error is within the allowable range,proving the accuracy of inverse and simulation.By analyzing the flow conditions on the radial surface of the fan,the pressure inside the fan flow was studied,there is a high pressure area near the pressure surface at the top of the blade,blade has a big impact on the air when rotating and affects its work efficiency.The number of blades is the most direct influencing parameter of radial straight blades.By analyzing the influence of different blade numbers on fan flow,it is found that the pressure and efficiency of fans increase with the increase of blade numbers,and the static pressure,total pressure and static pressure efficiency have more obvious effects with the increase of blade numbers.Through the simulation of the flow field inside the fan,the results show that the gas accumulation and stress concentration phenomenon exist at the fan inlet,which reduces the efficiency of the fan.Aiming at this phenomenon,the front disk inlet structure of the fan was improved.The results show that the improved fan static pressure efficiency increases by 13.4%,and the total pressure efficiency increases by 12.3%. |
PDF Full Text Request