Flow Control Technology For Helical Axial Flow Influence Of Drag Reduction In Internal Flow Of Gas-liquid Mixed Pump

Because the helical axial flow gas-liquid mixing pump has the great advantage of conveying gas-liquid two-phase mixed medium,it has become the main core equipment for deep-sea oil and natural gas exploitation.The gas phase aggregation and bubble movement trajectory in the impeller channel have been widely studied,but the increase in the medium flow resistance caused by the flow separation has not been deeply discussed.Combined with the Euler multiphase flow model and the SST turbulence model,the numerical calculation of the helical axial flow gas-liquid mixed pump is carried out.The effects of the bionic waveform leading edge structure,the vortex generator groove structure and the diversion groove structure on the drag reduction of the internal flow of the helical axial flow gas-liquid mixed pump were explored under the design flow conditions.The main research conclusions are as follows:（1）By designing the blades with different amplitude and wavelength leading edge structures,the separation of the mixed medium and the suction surface is effectively suppressed,and the flow resistance of the medium in the 1/10 area of the inlet end of the blade is reduced.Under the design flow conditions,when the amplitude A=0.25%L and the wavelength λ=1.25%L,the maximum drag reduction rate in this area is 52.6%,the maximum increase in the efficiency of the mixed pump is 2.2%,and the maximum increase in the head is 3.4%.（2）By arranging vortex generators with different relative depths in the area of X/L=0.3～0.5,the separation of the mixed medium and the suction surface is suppressed,and the flow resistance in the area where the vortex generators are arranged on the suction surface is reduced.Under the design flow condition,when the relative depth（δ1/D1）=3/40,the maximum drag reduction rate in this area is 36.7%,the maximum increase in the efficiency of the mixed pump is 2.1%,and the maximum increase in the head is 4.3%.（3）By arranging different relative depths and different numbers of guide grooves on the suction surface of the blade,the dissipation vortex is reduced,and the flow resistance in the rear 1/5 area of the suction surface is reduced.Under the design flow conditions,when the relative depth of the groove（δ₂/D₂）=1/7 and the number of diversion grooves is 5,the maximum drag reduction rate in this area is 64.4%.When the relative depth of the diversion groove（δ₂/D₂）=1/7 and the number of diversion grooves is 3,the performance of the mixed pump is improved the most,the efficiency increment is 1.9%,and the head increment is 4.2%.In this paper,the influence of the waveform leading edge structure,the vortex generator groove structure and the guide groove structure blade on the drag reduction of the internal flow of the helical axial flow gas-liquid mixed pump is obtained,which can be used for the flow drag reduction in the gas-liquid mixed pump.Provide technical support.