CUI Ying-tao,QIN Chao-bin,ZHANG Zhi,et al.Experimental Study on the Impact of Droplets on the Surface of Soybean Leaves [J].Soybean Science,2018,37(06):961-968.[doi:1011861/jissn1000-98412018060961]
液滴撞击大豆叶片表面研究
- Title:
-
Experimental Study on the Impact of Droplets on the Surface of Soybean Leaves
- Keywords:
- Droplet; High speed camera; We number; Spread diameter
- 文献标志码:
- A
- 摘要:
-
为提高大豆植保机械施药过程中的农药利用率,本文通过观察大豆叶片表面特征,分析大豆叶片生物性状,测量液滴在大豆叶片表面的接触角,测试大豆叶片表面的粘附性,进一步利用高速摄像机记录单液滴撞击大豆叶片过程。结果表明,液滴撞击的动态压力会使得液滴嵌入叶表结构当中,毛状结构亦能刺透并使液滴破裂,影响液滴撞击过程的破碎规律。随着液滴撞击速度的增加,液滴粒径大小为225 mm时,液滴铺展直径表现为先增加后减少,其中撞击速度134 m·s-1时,撞击We数5557,最大铺展直径为394 mm,当撞击速度≥103 m·s-1时液滴出现破碎喷溅,随着撞击速度增加液滴破碎、喷溅、弹离叶片表面的数量迅速增加,当撞击We数>3283时液滴撞击过程中出现不同程度的破碎、喷溅,当撞击We数<3283时液滴未出现破碎现象。改变粒径大小,随着粒径增大液滴铺展直径随之增加,当液滴粒径<219 mm时液滴撞击叶片表面后出现反弹,当液滴≥219 mm时液滴撞击过程有反弹趋势,但是撞击动能不足、叶片高粘附性等因素影响,液滴未弹离叶片表面。因此,当撞击速度在134 m·s-1,粒径219 mm时达到最佳值。
- Abstract:
- In order to improve the utilization rate of pesticides in soybean plant protection machinery, this paper analyzed the surface characteristics of soybean leaves, the biological characteristics of soybean leaves, measured the contact angle of droplets on the surface of soybean leaves, tested the adhesion of soybean leaf surface, and further utilized a high speed camera recorded the process by which a single droplet hited the soybean leaf The results showed that the dynamic pressure of the droplet impact caused the droplet to be embedded in the leaf surface structure, and the hairy structure could also penetrated and ruptured the droplet, which affected the breaking law of the droplet impact process With the increase of the droplet impact velocity and the droplet size of 225 mm, the diameter of the droplet spread increased firstly and then decreased When the impact velocity was 134 m·s-1, the impact number was 5557, the maximum spreading diameter was 394 mm When the impact velocity was ≥103 m·s-1, the droplets appeared to be broken and splashed As the impact velocity increased, the number of droplets breaks, splashes and bounces off the surface of the blade increased rapidly When the number was >3283, there were different degrees of crushing and splashing during the impact of the droplets When the impact number was <3283, the droplets did not break The particle size was changed As the particle size increased, the droplet spreading diameter increased When the droplet size was <219 mm, the droplet rebounds after hitting the surface of the blade When the droplet ≥219 mm, the droplet impact process had a rebound trend, but the impact of insufficient kinetic energy, high adhesion of the blade and other factors, the droplets did not bounce off the surface of the blade Therefore, the optimum value was obtained when the impact velocity was 134 m·s-1 and the particle diameter was 219 mm
参考文献/References:
备注/Memo
收稿日期:2018-07-10