Droplet size and spray pattern characteristics of PWM-based continuously variable spray

作     者：Deng Wei He Xiongkui Ding Weimin 

作者机构：College of ScienceChina Agricultural UniversityBeijing 100193China College of EngineeringNanjing Agricultural UniversityNanjing 210031China 

出 版 物：《International Journal of Agricultural and Biological Engineering》 (国际农业与生物工程学报（英文）)

年 卷 期：2009年第2卷第1期

页      面：8-18页

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

主　　题：Pulse Width Modulation(PWM) continuously variable spray droplet size spray distribution pattern spray angle 

摘      要：A Pulse-Width-Modulation-based(PWM-based)continuously variable sprayer was developed using a proportional regulating solenoid *** flow-rate was obtained by varying the duty cycle of the actuating signal with 24 kHz ***-rate regulating ranges of the PWM-based continuously variable spray(*** turndown ratio responding to 100%-40%duty cycle)are 7.14:1,3.57:1,and 3.70:1 for flat-fan,hollow-cone and solid-cone nozzles,*** purpose of the study was to evaluate the PWM-based continuously variable *** method was to quantify the effects of flow-rate control on spray characteristics in terms of droplet size spectra,spray distribution patterns,and spray angle for flat-fan,hollow-cone,solid-cone *** all nozzles tested,spray distribution concentrated on the center of the spray field with the decrease of *** the spray shape is still *** sensitivities of the spray angles to flow-rate were 0.83,0.67,and 0.58(o)/%respectively for flat-fan,hollow-cone and solid-cone *** with the sensitivities of spray angle for PWM-based intermittent variable spray,they are somewhat *** flow-rate was reduced from the maximum(100%flow-rate)to the minimum controllable rate,the observed median diameter of spray droplets decreased by 5.4%,9.8%,and 9.9%for flat-fan,hollow-cone and solid-cone nozzles,*** indicates that spray droplet size was affected slightly by flow-rate control.