Structure Optimization Of Driveing Impeller By Aero-engine Blade Grinding Instrument

The small blade damage repair without disassembly of the engine can usually be completed by pneumatic sander.However,the driving impeller of pneumatic sander works under open conditions.It is not enough to provide sufficient torque,which makes the grinding work difficult to complete efficiently.Therefore,in view of the defects in the original structure,this article designs a drive structure with good sealing performance.It effectively improves the aerodynamic efficiency and at the same time obtains a better aerodynamic grinding effect.First of all,the drive structure was designed through professional three-dimensional modeling software to make it have a good seal.Secondly,through the special software for fluid analysis,combined with the data measured in the rotating speed experiment,the threedimensional unsteady flow in the entire flow channel of the drive structure was simulated.After analyzing the results,the time domain and frequency domain characteristics of the pressure pulsation at the three main positions of the impeller inlet,impeller flow passage and impeller outlet under different flow conditions were obtained.Then,based on the above characteristics,noise data was extracted to obtain the sound power spectrogram of the impeller.The accuracy of the numerical simulation method of aerodynamic noise was verified by comparison with the experiment,and the impeller structure was improved by combining the results of the flow field analysis.The research results show that when the number of grids is more than 3 million,the numerical simulation results are basically consistent with the model test results.And the accuracy of the physical quantities solved by the numerical simulation method is higher.Under different flow conditions,the pressure pulsation values corresponding to different monitoring points all have shown strong regularity.The pressure pulsation in the impeller channel is the most complicated,and the impeller rotation frequency is the main frequency of the pressure pulsation.The secondary frequency is twice the rotating frequency of the impeller,among which there are more frequency divisions under large flow conditions.When there is too much deviation from the design conditions,more energy loss occurs in the impeller flow channel.By improving the structure of the impeller,and comparing the simulation data of the impeller with different characteristic parameters under the same structural characteristic.The geometric parameters of the impeller when the aerodynamic performance is the best are obtained,and the structure optimization of the driving impeller is finally realized.