Research On Parameterization And Simulation Analysis Technology Of Passenger Car Cooling Fan Numerical Model

With the development of the automotive industry,the cooling system’s heat dissipation demand is continuously increasing.Increasing the cooling fan performance is a feasible way to improve the heat dissipation performance.With the gradual application of computer technology and computational fluid dynamics to model design analysis,a considerable amount of time and cost can be saved,simulation modeling can reduce the number of experiments,and parameterized models make it possible to simultaneously search for a large number of design solutions.This article mainly studies the parameterized modeling technology of cooling fans and the automatic simulation analysis method based on CFD software development.This article first introduces the relevant knowledge of cooling fans and the basic theory involved in simulation analysis.Then,based on the physical and three-dimensional models of the passenger car cooling fan provided by the enterprise,the numerical simulation analysis method of the cooling fan is studied.The steady-state simulation analysis of the cooling fan,including the impeller and stator parts,is performed using the fluid simulation software STAR-CCM+.A simulation model is established,including a mesh model,boundary condition settings,fluid solution models,and performance indicators such as fan power,static pressure efficiency,flow rate,average dipole noise,and maximum quadrupole noise under steady-state conditions.A corresponding automatic simulation Java script program is designed to improve the automation and efficiency of simulation.The basic structure of the parameterized model is defined according to the common axial fan.The flat airfoil is designed based on parameters such as chord length,airflow angle,installation angle,and publicly available NACA wing thickness data.Nine flat airfoils are projected onto a cylindrical surface,and the offset of the airfoil section is controlled by parameters such as blade deformation coefficient and blade bending deformation direction.Then,they are stacked into a three-dimensional blade.The fan hub and shroud are designed as a rotating body that can accommodate the blade tip and root section.The circumferentially non-uniform distribution position of the blade is calculated according to the dynamic balance theory.The design of the fan model is parameterized.By measuring the parameter values of the physical fan’s three-dimensional model corresponding to the numerical model,a parameterized numerical model of the physical fan is generated.The consistency of the performance curve between the parameterized numerical model and the physical model is compared through simulation analysis,verifying the reliability and practical value of the parameterized model.Finally,this article studies the impact of characteristic parameters of the parameterized model on fan performance,such as chord length,installation angle,hub-to-tip ratio,number of blades,circumferential distribution of blades,and parameters of the impeller and shroud.Under the condition of ensuring that other parameter conditions remain unchanged,the impact of the studied parameter changes on fan performance is analyzed,providing feasible directions for optimizing the fan.