Venturi Fertilizer Hydraulics Performance Test And Numerical Simulation

By the CT scanning methods,this paper get three kinds of throat structure and 14 kinds of flow channel in the form of Venturi injector.After modeling with the scan files,import to the CFD numerical simulation.Finally,make comparative analysis with experimental data,the rationality of the numerical simulation method are verified.After testing some different of inner field structure of Venturi injector,explore the influence of fertilization performance in different throat structure and regulation mechanism.Proposes an improved scheme on the basis of completing test and numerical simulation,executes tests and analysis last.The following conclusions:(1)To the different structure of venturi injector,with the increase of inlet flow,fertilization efficiency will decrease trend,and with the increase of import of throat diameter,decreasing trend of fertilization efficiency has gradually become slow;The smaller throat inlet diameter,with the increase of flow rate,the more rapidly on fertilization efficiency.When the inlet flow is constant and ?= 1.27,the fertilization efficiency of throat is largest.(2)Under the same inlet flow,the fertilization efficiency of T throat is largest;In the same inlet flow interval,decreasing rate of fertilization efficiency of T throat is the largest.To the different structure of throat,with the increase of inlet flow,in the absence of sucking,the negative pressure gradually reaches the minimum and keep the lowest constant.The fertilizer suction amount of T can be effectively improved,but with the increase of inlet flow,the pressure between inlet and outlet will increase.(3)To different venturi injector,inlet flow rate had a great influence on its performance smaller proportional control in the outlet valve.For Venturi injectors that have the same reducing-tube and expanding-tube,smaller the throat diameter is,the more flexible;With the increase of diameter of import throat,the greater impact on the outlet valve.Within the scope of the small flow,throat diameter are the main factors influencing throat negative pressure,with the increase of inlet flow,the influence of the outlet valve gradually appear.When ?= 1,the performance of T throat is stronger within the scope of the regulation of outlet valve,and stronger than C and E throat;When ?= 1.33,the T throat has the most stable performance.(4)When the Venturi injector have sucting and outlet valve in the fully open position,fertilization efficiency is often showed a trend of decrease after the first increase.Under the large flow,fertilization efficiency of T throat has smaller affected by outlet valve than C and E.Comprehensive contrast ?= 1 and ? = 1.33 in both cases,T throat has the most stable performance,compare to C and E,the influence of the outlet valve is small.When the throat diameter is constant,suitable for use T throat in Venturi injector.(5)The results of numerical solution show that the best convergent angle is about 40°.