As the core component of car seat ventilation and heating systems,the performance of the centrifugal fan has a direct impact on the passenger experience.The pneumatic performance of a centrifugal fan is measured by the fact that it has a higher outlet static pressure at the same airflow or a higher airflow at the same outlet static pressure.With the development of Computational Fluid Dynamics(CFD),the application of CFD technology instead of traditional experimental sample testing to calculate the internal and external characteristics of the centrifugal fan can be a convenient way to shorten the calculation time and reduce costs for engineering product.However,current research on centrifugal fans is primarily concentrated on large centrifugal fans in the industrial refrigeration sector,with less research in the field of small seat fans,whose properties are still not known to be universal.In order to obtain a centrifugal fan with high aerodynamic performance,this paper investigated and optimized the impeller structure of a centrifugal fan based on traditional design using CFD,response surface methodology and optimization algorithms.First of all,CFD and the control variable method were used to study the influence of four parameters,namely the impeller blade number,blade outlet angle,blade inlet angle and blade thickness,individually on the external characteristics of the ventilator.It was found that the maximum static pressure value achievable by a centrifugal fan with an even blade number is higher than with an odd blade number.An increase in the blade number,blade inlet angle and blade outlet angle all bring about an increase in the outlet static pressure of the centrifugal fan,while the opposite is true for blade thickness.According to the single factor analysis,the response surface method is used to research the effect of the interaction of the above four parameters on the aerodynamic performance of the ventilator.The study shows that the interaction between the blade outlet angle and blade thickness has an significant effect on the outlet static pressure of the centrifugal fan,and the main order of influence of each parameter on the static pressure of the centrifugal fan is blade outlet angle,blade thickness,blade inlet angle and blade number.Eventually,the combination of parameters that can achieve the best aerodynamic performance of the centrifugal fan is optimized by genetic algorithm.In addition,the external characteristic curves and the internal flow field of the centrifugal fan before and after optimization were compared and analysed.It was found that the external characteristic curves of the optimized centrifugal fan were superior to those of the existing fan,and that the static pressure could be increased by 8.36% to26.68% in the high efficiency region,and that the internal pressure and flow velocity were more evenly distributed,which was more conducive to the entry of airflow.The research process and results are of guidance for the design and development of high performance centrifugal fans. |