Research On Cavitation Characteristics Of Automobile Cooling Water Pump

Automobile cooling water pump is an important component in the engine system,and its performance determines whether the engine can run normally.With the rapid development of the automotive industry,the demand for automobiles is increasing.As an important equipment for the stable operation of automobiles,automotive cooling water pumps cause problems such as low efficiency and high energy consumption due to cavitation.Therefore,this paper conducts related research on water pumps.This paper takes a certain type of automobile cooling water pump as the research object,adopts the numerical simulation technology to carry out steady and unsteady constant value simulation on the inside of the automobile cooling water pump,then conducts cavitation research on the inside of the water pump,and finally analyzes the pressure pulsation characteristics.The main research contents and results of this article are as follows:1.Carry out the single-phase steady calculation of the water pump.From the external characteristic curve,it can be seen that the highest efficiency point appears at the design condition point,and the efficiency is 80.41%;then the pressure and speed distribution in the pump are analyzed separately,from the pressure and velocity clouds can be drawn: the pressure distribution of the pump is uniform under different working conditions,the lowest pressure area is located at the inlet of the impeller and the highest pressure at the outlet of the volute;when the liquid flows into the impeller,its speed gradually increases and reaches the maximum value at the outlet of the impeller.After flowing through the volute,the speed gradually decreases and decreases to the lowest value at the outlet of the volute.2.Carry out cavitation analysis of the water pump,mainly to study the pressure and streamline distribution of water pump,the distribution of cavitation on the impeller cut surface,and the distribution of cavitation on the middle section of the impeller.Under the design conditions,by reducing the inlet pressure,the critical cavitation margin is obtained,which can be obtained from the pressure distribution diagram: under the critical cavitation margin,the low-pressure region in the impeller is larger;from the streamline distribution diagram,it can be obtained: as the cavitation margin decreases,The low-speed area in the impeller is increasing,and under the critical cavitation margin,each blade is distributed with vortices of the same size,indicating that the flow in the impeller is quite complicated at this time;from the distribution of cavitation in the impeller cut surface and the middle section,it can be concluded that the cavitation is mainly distributed at the position of the head of the suction surface of the blade,and as the cavitation margin decreases,the cavitation even diffuses into the intermediate flow channel.and has now developed into a complete cavitation3.A comparative analysis of the pressure pulsation with or without cavitation under the design conditions of the water pump.The main frequency of the pressure pulsation at each monitoring point in the circumferential direction of the volute is the leaf frequency,and it presents a strong period during both rotation cycles.The amplitude of the pressure pulsation under cavitation of the volute is larger than that without cavitation.The main frequency of pressure pulsation at each monitoring point on the suction surface and pressure surface of the impeller is the leaf frequency,which is mainly concentrated in the low frequency area.Cavitation mainly occurs at the inlet of the impeller,so the pressure pulsation coefficient at the first monitoring point of the blade suction surface is 0.