Study Of Flow Rate Control Performance Of A Venturi Tube

Hydrodynamic cavitation has the advantages of pollution-free,high efficiency,and larger amount of instantaneous power.A Venturi tube has the characteristics of simple structure,safety and durability and working without external energy.Venturi tubes are used in petrochemical industry,coal chemical industry,nuclear and other industries.The cavitation flow in a Venturi tube used as a nuclear steady flow rate equipment was simulated based on the Realizable k-? turbulence model and Zwart cavitation model in this paper to calculate the flow rate.The hydrodynamics characteristics and flow rate control performance of Venturi tubes were studied combined the experimental research from other literatures by using the CFD methods and FLUENT software.The simulation of the flow rate were well fitted with the experimental data and the maximum error was 5.5%.The Venturi tube has obvious stabilizing effect on the flow rate growth,and the hydraulic cavitation is the internal force of the steady flow rate effect on different pressure difference conditions.The throat diameter is the key size to the performance of Venturi tube steady flow rate.The more sensitive of the Venturi tube to the growth and fluctuation of flow rate with a smaller throat diameter,and gasification phase transition is easier to occur.The flow rate growth is small and the steady flow effect is better.The throat length has a maj or impact on the sensitivity of flow rate control effect.The sensitive and timeliness of the Venturi tube flow rate control performance is better with a smaller throat length.The pressure level affects the generation of cavitation phase transformation.Low pressure condition make the sensitive of Venturi tube flow rate control performance is better,and high pressure make the flow development more stable with a smaller increment of flow rate.Internal surface roughness of Venturi tube affects the performance of steady flow rate by the direct action on the formation and development of cavitation phase change.The sensitivity and performance of steady flow rate effect is better with a smaller Ra,and the gasification phase transition is easier to occur.The vapor volume fraction of the cavitation area is changing by the water temperature increases from 5? to 90? with the inlet pressure is 0.2MPa and the outlet pressure is 0.1 MPa.Gas content of water plays a leading role in the affection of vapor volume fraction on the temperature range of 15? to 30?.On the other temperature range,the saturated vapor pressure is the main influence.The cavitation steady flow rate performance is studied by numerical simulation method in this paper.The research results of this paper provide some theoretical basis to the application of Venturi tube in the related industries and other fields,which have great value and importance in engineering practice and analytical theory.