Spray performance downward the plain orifice injector was numerically simulated by using Fluent. The primary breakup and the secondary breakup were both focused. To capture the instantaneous interface of two-phase flo...Spray performance downward the plain orifice injector was numerically simulated by using Fluent. The primary breakup and the secondary breakup were both focused. To capture the instantaneous interface of two-phase flow and multiscale structure of liquid spray more accurately,an adaptive mesh refinement(AMR) method was adopted. Firstly,the velocity distribution and jet structure were obtained. Then,with different coupled VOF(Volume of Fluid)-DPM(Discrete Phase model)strategies,the jet trajectory,the column breakup point,and the time-average SMD distribution were analyzed and compared. Meanwhile,the experimental data and several empirical formulas were applied to verify the numerical value. The results suggested that the numerical simulation could accord well with experimental data and a certain formula.展开更多
The most usual way of using chemical method to protect crop against weed, insects, and fungi is spraying the mixture of chemicals and water onto crop through the nozzles. Sprayers usually moved on the field by tractor...The most usual way of using chemical method to protect crop against weed, insects, and fungi is spraying the mixture of chemicals and water onto crop through the nozzles. Sprayers usually moved on the field by tractor, and tractor induced unwanted vibration to sprayer because of uneven soil or terrain. This oscillation leads to over-doses and under-doses of chemical sprayed on the field. For this reason, many commercial and some theoretical suspension were made to reduce undesirable vibration. Therefore, in this study a finite element based model was established to represent the dynamic behavior of spray boom structure with 8m width. The first tenth natural frequencies were obtained between 9.25 Hz to 1,182.5 Hz. Also, a passive vertical suspension was designed to remove unwanted vibration with 0.5 vibration transmissibility. Finally, the suspension system was simulated to be as certain of its efficiency. The results of simulation have good agreement to the proposed aim.展开更多
基金supported by the National Natural Science Foundation of China(No. 91741118)
文摘Spray performance downward the plain orifice injector was numerically simulated by using Fluent. The primary breakup and the secondary breakup were both focused. To capture the instantaneous interface of two-phase flow and multiscale structure of liquid spray more accurately,an adaptive mesh refinement(AMR) method was adopted. Firstly,the velocity distribution and jet structure were obtained. Then,with different coupled VOF(Volume of Fluid)-DPM(Discrete Phase model)strategies,the jet trajectory,the column breakup point,and the time-average SMD distribution were analyzed and compared. Meanwhile,the experimental data and several empirical formulas were applied to verify the numerical value. The results suggested that the numerical simulation could accord well with experimental data and a certain formula.
文摘The most usual way of using chemical method to protect crop against weed, insects, and fungi is spraying the mixture of chemicals and water onto crop through the nozzles. Sprayers usually moved on the field by tractor, and tractor induced unwanted vibration to sprayer because of uneven soil or terrain. This oscillation leads to over-doses and under-doses of chemical sprayed on the field. For this reason, many commercial and some theoretical suspension were made to reduce undesirable vibration. Therefore, in this study a finite element based model was established to represent the dynamic behavior of spray boom structure with 8m width. The first tenth natural frequencies were obtained between 9.25 Hz to 1,182.5 Hz. Also, a passive vertical suspension was designed to remove unwanted vibration with 0.5 vibration transmissibility. Finally, the suspension system was simulated to be as certain of its efficiency. The results of simulation have good agreement to the proposed aim.
