Simulation research on dynamic performance of the new type high-pressure solenoid valve

To improve energy density,the transportation,storage,and operations of hydrogen,methane,and compressed air vehicles currently require high-pressure compression.High-pressure solenoid valve becomes the vital element to above system.In order to reduce leakage and aerodynamic force influence,a new type high-pressure solenoid valve was proposed.The simulation model which included electromagnetic model,aerodynamic force model was established by means of the nonlinear mathematic models.Using the software MATLAB/Simulink for simulation,the dynamic response characteristics of high-pressure pneumatic solenoid valve were obtained under different pulse width modulation(PWM)input control signals.Results show that,first of all,the new type of high-pressure solenoid valve can meet the switch requirement.Secondly,the opening movement and closing movement of the spool lags the PWM rising signal,and the coil current fluctuates significantly during the movement of the spool.Lastly,on/off status of high-pressure valve cannot be represented by the duty cycle.This research can be referred in the design of the high-pressure solenoid valve..

Dynamic spreading characteristics of droplet impinging soybean leaves

The study on the deposition efficiency of pesticide droplets on soybean leaves can provide the basis for reducing pesticide quantity and increasing pesticide efficiency during the application of soybean plant protection machinery.The movement behavior of droplet impinges on the plant leaf surface is affected by many factors,among which the most important and the easiest to adjust are spray droplet size and impingement velocity.By changing the droplet size and impact velocity and using Fluent simulation software,the pesticide droplet hitting the soybean leaf surface was simulated and a test platform was established to verify the simulation results.The conclusions are as follows:The longitudinal roughness of soybean leaves is higher than the transverse roughness,the longitudinal pressure of soybean leaves is higher than the transverse pressure during the impact process,and the velocity of droplet spreading along the longitudinal is lower than that of spreading along the transverse;although soybean leaf surface has high adhesion,droplet losses still exist when droplet impact velocity is relatively high.The maximum spreading diameter of the droplet increases first and then decreases with the increase of impact velocity.At the same time,the maximum spreading diameter of droplet increases with the increase of particle size.The droplet deposition was best at 1.34 m/s impact velocity and 985μm particle size.This conclusion can provide optimal operation parameters for soybean plant protection operation which can be used to guide soybean plant protection operation,improve control effect,reduce quantity and increase efficiency.