Analysis And Optimized Design Of Vibration Characteristics Of Vacuum-pumped Impeller

The vacuum non-destructive excavation and aspiration vehicle is a new type of construction equipment,and it is rapidly developed because it will not cause damage to the environment during the construction process.The vacuum suction impeller is the core working part of the excavation and aspiration vehicle,and its structural strength directly affects the safety of the equipment.Therefore,the structural strength of the vacuum suction impeller that ensures high-speed operation is of great significance for ensuring the safe operation of the system.In this paper,the analysis of inlet flow field and internal flow field,analysis of vibration characteristics and optimization of stress and strain are studied for vacuum suction impeller.The main contents of the study are as follows:(1)Analyze the inlet and outlet flow passages of the linear and curved type of the vacuum suction impeller,and compare the straight flow passage with the curved flow passage from the inlet flow field distribution and the centrifugal fan efficiency.It is more suitable for the inlet flow channel scheme of the vacuum non-destructive suction car;the flow field distribution in the suction impeller under four different working conditions is studied,and the relationship between the distribution of the inner flow field of the impeller and the rotational speed is obtained,and the theory is obtained.The comparison between the full pressure value and the simulated value verifies the correctness of the calculation model.(2)The stress-strain analysis of the vacuum suction impeller is mainly divided into three parts: the stress and strain analysis of the impeller under aerodynamic loading,the stress and strain analysis of the impeller under centrifugal force,and the stress and strain analysis of the impeller under fluid-solid coupling.The influence of aerodynamic loads on the stress and strain of the impeller is studied,and the stress and strain of the impeller are obtained.(3)Aiming at the possible vibration problems of the vacuum suction impeller during operation,the modal analysis of the impeller and the harmonic response analysis of the hammer modal test were carried out respectively,and the vibrationstate of the impeller in actual operation was studied.(4)Response surface analysis method is used to optimize the impeller.Then,according to the stress and strain trend of the impeller,an optimization method based on blade chamfering is proposed.Finally,the two optimization methods are combined to obtain the final optimization scheme.The calculation shows that the maximum equivalent stress of the vacuum suction impeller is reduced by 21.42%,the maximum strain value is reduced by 16.30%,and the total mass is reduced by 16.84%.The optimized impeller not only has a significantly reduced mass,but also has a very good structural strength,which is of great significance for the stable and efficient operation of vacuum non-destructive dredging vehicles.