Research on aerodynamic performance and noise reduction of high-voltage fans on fuel cell vehicles

Due to the much higher cooling requirements of fuel cell vehicles, 350-Volt high-voltage fans are adopted instead of traditional 12-volt cooling fans, generating more aerodynamic noise. This paper is aimed at studying the aeroacoustic optimization methods of high-voltage fans on fuel cell vehicles on the basis of ensuring aerodynamic performance. The flow field and sound field characteristics of a high-voltage fan assembly are solved and analyzed by numerical simulation methods. The fan outer ring structure, blade installation angle, and circumferential blade spacing are adjusted to optimize the fan performance. Then, a bench test is conducted to verify the optimization results of the high-voltage fans. Under the premise of ensuring the same aerodynamic performance, the optimized fans can achieve a noise reduction of 1–1.5 dB at each speed. In order to enhance the optimization effect, an optimal design strategy of the surrounding layout parameters of a dual fan system is developed. Four key positional parameters between fans and surrounding components are selected, the flow rate and the sound pressure level of the entire fan system are used as evaluation indexes. According to the response surface method, a Box-Behnken test is designed and the quadratic regression agent model is adopted to construct relationships between fan performances and boundary parameters. A comprehensive evaluation function of fan performance is proposed and solved to obtain the optimal layout strategy of the dual fan system. The flow rate of the optimized fan system receives an increase of 12.8%, and the noise index shifts down by 0.98 dB. The proposed methods can provide reference significance for the design and optimization of high-voltage fans with low noise and high aerodynamic performance.