机构地区:[1]江苏大学流体机械工程技术研究中心,镇江212013 [2]华盛顿州立大学农业灌溉研究发展中心,美国普罗瑟99350
出 处:《农业工程学报》2015年第15期26-31,共6页Transactions of the Chinese Society of Agricultural Engineering
基 金:国家高技术研究发展计划(863)项目(2011AA100506);国家自然科学基金(51309117);中国博士后科学基金特别资助(2014T70484);中国博士后科学基金(2015M570415)
摘 要:喷灌动能是评价喷头水力性能优劣的重要指标之一。该文在0.15、0.20、0.25、0.30和0.35 MPa工作压力下,采用激光雨滴谱仪测量技术(laser precipitation monitor,LPM)对全射流喷头的水滴直径、速度和水量分布等参数进行试验,研究了单个水滴动能、单位体积水滴动能、动能强度分布规律及动能强度均匀性系数与组合间距之间的关系。结果表明:全射流喷头的单个水滴动能分布与水滴直径之间的关系与该文所建立的模型拟合较好,呈幂函数关系;单位体积水滴动能沿径向呈一次函数关系增大,与压力的-0.556次方呈正比关系;动能强度沿径向逐渐增大,而在射程末端迅速减小至0,随压力增大而减小,且沿径向距离的增大而动能强度减小程度越大;在各工作压力下,全射流喷头的矩形最佳组合间距分别为1.2、1.0、1.1、1.0、1.1倍喷头射程;所对应的动能强度均匀性系数分别为56.6%、71.1%、76.2%、77.2%、72.9%。该结果对研究喷头外特性、优化喷头结构、喷灌系统优化配置提供了一定的理论价值。The kinetic energy of sprinkler spraying is an important factor to evaluate sprinkler hydraulic performance, and has a great significance to study soil and water conservation. The kinetic energy of sprinkler spraying mainly includes the droplet kinetic energy, the kinetic energy per unit volume, the kinetic energy intensity and the uniformity coefficient of kinetic energy intensity. All of them are closely related to the hydraulic parameters of sprinkler. The hydraulic parameters contain the water distribution, the droplet diameter and the droplet velocity. To study the kinetic energy distribution of PXH, PXH10 sprinkler hydraulic parameters were tested under the no wind condition, with the operating pressure of 0.15, 0.20, 0.25, 0.30 and 0.35 MPa, respectively. The single sprinkler water distribution was measured by catch cans. The catch cans were placed on the testing stand with a spacing of 2 m × 2 m. The laser precipitation monitor(LPM) was used to measure the droplet diameter and velocity. The results showed that the kinetic energy of sprinkler spraying distribution of PXH was different from the other types of sprinklers. The droplet kinetic energy increased with the increase of the droplet diameter. The relationship between droplet kinetic energy and droplet diameter of PXH was indicated by the power function model. The correlation coefficients for the model were up to 0.9 in different pressures. It increased by an average of 20% compared with the other models which were used to show the droplet kinetic energy distribution of PXH. Under different pressures, both the droplet kinetic energy and the kinetic energy per unit volume reached a maximum at the end of the spraying wetted radius. When the pressure increased, the maximum of the kinetic energy per unit volume decreased. The kinetic energy per unit volume increased linearly with the distance from the sprinkler increasing. There were proportional relationships between kinetic energy per unit volume and operating pressures. The proportional function m
关 键 词:喷灌系统 动能 喷洒 水滴 全射流喷头 动能强度 动能强度分布均匀性系数
分 类 号:S277.94[农业科学—农业水土工程]
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