Research On Solid-liquid Two-phase Flow Of Water Jet Propulsion Pump

Water jet propulsion pump is the core driving equipment of water jet propulsion system,which has been widely used in ship thrust and other fields.However,its design method is often based on a single-phase purification pump,and its thrust performance in actual river-containing sediment water cannot be measured.Therefore,it is of great significance to study the external characteristics,internal flow rate and thrust characteristics of the solid-liquid two-phase flow of the water jet propulsion pump.In this paper,through theoretical analysis,similar conversion of external characteristics,thrust test and numerical calculation,the effect of the pump solid-liquid two-phase flow is systematically studied.The main work and innovation results are as follows:The performance of river water jet propulsion pumps with different sediment concentrations was studied for the first time.The numerical calculation method of hydraulic mechanical solid-liquid two-phase flow is introduced into the research of water jet propulsion pump.The reliability of the numerical calculation method can be verified by similar conversion of the test results of pump external characteristics and thrust characteristics.By comparing the numerical results of different turbulence models,it is determined that the standard k-? model is the most suitable turbulence model for water jet propulsion pumps.Based on this,single-phase numerical calculation and solid-liquid two-phase flow numerical calculation were performed.The results show that as the pump speed increases and the pump flow decreases,the pump thrust value shows an upward trend.Under the condition of 2000 r/min,the pump thrust can reach 1.9 times of the rated working condition.At the same time,the efficiency value changes with the change of pump speed and flow rate,and generally shows a trend of first rising and then falling.For low volume fraction and low particle size precipitation water,the effect of solid volume fraction and solid particle size on pump performance is limited.Compared with pure water,when the solid volume fraction is 3%,the pump thrust decreases by 7%,and when the solid particle size is 0.3 mm,the pump thrust decreases by 4%.In addition,the effects of different pump speeds on thrust values under solid-liquid two-phase flow conditions are basically consistent with single-phase numerical calculations.