双向对冲流灌水器水力性能和消能机理模拟与验证  

Numerical simulation and verification of hydraulic performance and energy dissipation mechanism of two-ways mixed flow emitter

作　　者：郭霖[1] 白丹[1] 王新端[1] 何靖[1] 周文[2] 程鹏[2] Guo Lin Bai Dan Wang Xinduan He Jing Zhou Wen Cheng Peng(Institute of Water Resources and Hydroelectric Engineering, Xi ＇an University of Technology, Xi＇an 710048, China School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou 450011, China)

机构地区：[1]西安理工大学水利水电学院,西安710048 [2]华北水利水电大学水利学院,郑州450011

出　　处：《农业工程学报》2017年第14期100-107,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(51279156;41571222);高等学校博士学科点专项科研基金联合资助课题(20116118110010)

摘　　要：为研究双向对冲流灌水器的水力性能和消能机理,安排25组试验方案,开展流量测试与模拟计算,选取模拟精度较高的湍流模型计算不同压力区间的流态指数、正反向水流流量比,分析正反向水流分布情况。结果表明,RNG k-ε模型的流量计算值与实测值的相对误差为1.656%~3.151%,与其他模型相比,RNG k-ε模型的相对误差较小;灌水器的流态指数为0.414~0.483,水力性能良好,尤其在低压区间,流态指数为0.414~0.456,正反向水流流量比趋近于1,水力性能更加突出;随压力的增大,反向水流的流量增幅较快,流量比减小,水力性能降低;正反向水流在挡水装置的齿尖形成对冲与混掺是消能的核心,而水流分布不均会影响灌水器的消能效果;在灌水器边壁增加多个改变流向的挡水装置,可优化双向水流配比,提高水力性能,从而验证不同压力区间、不同流量比与水力性能的内在关系。研究可对灌水器结构优化、水力性能提高提供参考。The two-ways mixed flow emitter is a new kind of drip irrigation emitter. The main working principle is forming the mixed phenomenon of forward and backward flow to increase more local head loss and eliminate extra inlet pressure. Computational Fluid Dynamics （Fluent software） plays an important role in analyzing hydraulic performance, flow field characteristic and energy dissipation mechanism of drip irrigation emitter. In order to study the hydraulic performance and the energy dissipation mechanism, we chose 5 key geometric parameters as factors and designed 25 sets of experimental schemes according to the orthogonal experimental design method. The flow rate and flow index under different pressures were determined by testing and simulating. Laboratory experiments were carried out in State key laboratory Base of Eco-hydraulic Engineering in Arid Area, Xi＇an University of Technology. In this paper, 5 turbulence models including standard k-e model, RNG k-e model, realizable k-e model, standard k-co model and SST k-co model were chosen and compared, respectively. Based on the flow rate of each experimental scheme within the range of 50-250 kPa, the relative errors of the experimental and simulated flow rate of these 5 models were compared, respectively. The more precision turbulence model was chosen. The flow index, the flow ratio of the forward flow to the backward flow, and the flow field distribution in different pressure were calculated and analyzed, and the relationship between them was explored. The results showed that the simulated results of RNG k-e model were better than that of the other 4 models. The relative error between the test value and the simulated value of RNG k-e model was from 1.656% to 3.151%, which was the minimum error among these 5 models. Especially, when the pressure was in the range of 50-150 kPa, the simulated values were much closer to the test values with the determination coefficient of 0.998 and the relative error of 1.28%-1.89% in the pressure of 50-150 kPa, which could accur

关 键 词：消能 数值分析 流量 灌水器 水力性能 

分 类 号：S275.6[农业科学—农业水土工程]