Centrifugal fans,due to their high pressure coefficient and small size,are widely used in the field of vehicle-mounted vacuum cleaners.However,during operation,they often suffer from low efficiency and surge problems,affecting the fan’s performance.This paper focuses on the comprehensive performance of centrifugal fans for vehicle-mounted vacuum cleaners,based on numerical simulation combined with experimental verification research methods,studies the flow field state of the air duct and the impeller deformation and vibration characteristics,aiming to improve the aerodynamic performance and operational stability of the fan.This paper proposes an optimization design method for the impeller and stator guide vane structure,reveals the mechanical characteristics of the impeller under different working conditions,and provides guidance for the optimization design of the fan duct structure and suitable working conditions.The main contents of the work are as follows:(1)According to the working characteristics of the C45 centrifugal fan model and the aerodynamic performance experimental scenario,a flow field model is established.The RNG k-ε turbulence calculation method is used to predict the aerodynamic performance of the prototype fan.The reliability of the numerical simulation method is verified by comparing the experimental data,and a visualization analysis of the internal flow field of the fan is conducted.The research results point out the shortcomings in the prototype fan’s duct structure.(2)The impact of impeller structure on the aerodynamic performance of the fan is studied through numerical simulation under different blade shapes and unequal blade numbers.A new structure is proposed,in which the guide vane and stator blades are designed as one integrated stamped part.The flow field state inside the guide vane and stator blade duct is simulated,and the stator blade shape is fitted according to the airflow trajectory.The fan’s aerodynamic performance is analyzed under different blade chord lengths,blade heights,and blade numbers.The feasibility of the duct optimization scheme is verified through aerodynamic performance experiments.The research results show that the vacuum degree at the design operating point of the optimized fan has increased by 1%,and the fan efficiency has improved by 4%.(3)The impeller strength is checked at the design operating point,and the dynamic characteristics of the impeller under aerodynamic load and absolute vacuum conditions are compared and analyzed.The main causes of stress deformation in the impeller are studied in conjunction with the modal response under different states,and the rules for stress deformation and aerodynamic performance changes of the impeller under varying rotational speeds are derived.The simulation results are verified through experiments on the impeller’s limit rotational speed,and the limit rotational speed value when the impeller fractures is determined,providing a reference for the allowable critical rotational speed design of the impeller.The research results show that the aerodynamic load does not have a significant impact on the stress deformation of the impeller,while the effect caused by the centrifugal force due to rotation is more pronounced.It is suggested to consider increasing the rotational speed appropriately to improve the aerodynamic performance of the fan,provided that the allowable stress of the impeller is met. |