Study On Drag Reduction Capability Of Bionic Dimple Impeller And Dynamic Characteristics Of Centrifugal Pump

With increasing requirements in energy consumption and acoustic abilities for universal fluid machinery,it is more concerned about the energy conservation,efficiency enhancement,vibration and noise reduction for centrifugal pumps.Traditional method is limited to its performance enhancement and high manufacture cost.Bionic non-smooth drag-reduction is a new method,which is easier to be realized and operated.It has been used in many fields and obtains good results,which can be explained by controlling boundary layer.This paper has employed bionic non-smooth theory to a single-suction centrifugal pump and carried out bionic drag-reduction exploratory research.The main contents are as follows:The drag coefficient of dimple plate are simulated and compared with theory results.Based on the bionics design rule,the centrifugal pump blades are designed with non-smooth unit parametrically,which has fully considered the operation principle and structure feature of pump.Dimple units are distributed in the exit of blades.The flow filed of the centrifugal model pump,which is designed with dimples on pressure surface,are simulated.The space between dimples is regarded as main parameters,and the external characteristic are analyzed.The flow and pressure fluctuation of dimple region are investigated.The forces exerted on impeller are analyzed by FFT method,focusing on the change of amplitudes in certain frequency.The suction surface on impeller is designed with dimples,the flow and drag-reduction characteristics are analyzed.The performance characteristics and the forces exerted on impeller are calculated for dimples with different radius.The flow of dimple region are investigated,and the results are compared with the case of dimples on pressure surfaces.The shaft model is established to calculate twist vibration and torsion response are analyzed with dimple impeller.The vibration characteristics of pump structure is analyzed and FEM model is corrected by model test results.Then,the response exerted on smooth impeller forces is calculated and validated by comparing with test results.The response of dimple impeller models is calculated.