双向对冲流灌水器模拟精度综合评价指标  

Comprehensive evaluation indicator of simulation accuracy for two-way mixed flow emitter

作　　者：郭霖[1,2] 白丹 王新端[1] 王程[1] 周文 程鹏 GUO Lin;BAI Dan;WANG Xinduan;WANG Cheng;ZHOU Wen;CHENG Peng(Institute of Water Resources and Hydroelectric Engineering,Xi'an University of Technology,Xi'an,Shaanxi 710048,China;Management Committee of Xi'an Chanba Ecological District,Xi'an,Shaanxi 710024,China;School of Water Conservancy,North China University of Water Resources and Electric Power,Zhengzhou,Henan 450011,China)

机构地区：[1]西安理工大学水利水电学院,陕西西安710048 [2]西安浐灞生态区管理委员会,陕西西安710024 [3]华北水利水电大学水利学院,河南郑州450011

出　　处：《排灌机械工程学报》2020年第8期848-854,共7页Journal of Drainage and Irrigation Machinery 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项目(20116118110010)。

摘　　要：为了评价数值模拟方法对双向对冲流灌水器的计算精度和适用性,设计3种灌水器样机,以试验测得的流量值与PIV测得的流速值为依据,提出评价模拟精度的宏观流量评价指标和微观流速评价指标.从宏观和微观2个角度评价15种数值模拟组合方案与试验结果的吻合程度,并建立综合评价指标模型,采用变异系数法计算2个评价指标的权重系数.结果表明:采用宏观评价指标得到增强壁面函数和RNG k-ε模型的流量偏差率最小,其宏观评价指标值为1.592%;采用微观评价指标得到增强壁面函数和SST k-ω模型的流速偏差率最小,其微观评价指标值为2.095%,2个指标的权重系数分别为0.6和0.4;对其进行综合评价,其中增强壁面函数和SST k-ω模型的综合评价指标值最小,为2.031%;进一步验证综合评价模型,其验证样机的模拟值与实测值的综合评价指标值为1.307%,证明了灌水器模拟精度综合评价指标的准确性.综合评价指标的建立提供了一种分析数值模拟精度的思路.In order to evaluate the calculation accuracy and applicability of the numerical simulation method for two-way mixed flow emitter,3 kinds of emitter prototypes were designed.Based on the measured flow rate and fluid velocity measured by particle image velocimetry(PIV)technology,the values of flow rate and fluid velocity were obtained under different pressures.The macroscopic flow rate evaluation indicator and microscopic fluid velocity evaluation indicator were proposed.From the aspects of macroscopic and microscopic respectively,the precision about 15 kinds of numerical simulation combination schemes in numerical simulation software was contrasted and analyzed.The comprehensive evaluation indicator model of different evaluation items was established,and the weight coefficients of two evaluation indicators were calculated by using variation coefficient method from a point of view of objective weighing.The analysis results show that numerical simulation accuracy of the enhanced wall function is higher and better.First,on the basis of macroscopic evaluation indicator,the numerical simulation value using the enhanced wall function and RNG k-ε physical model can more accurately reflect the real flow rate of emitter,and the value of macroscopic evaluation indicator is 1.592%,which is minimal with the flow rate deviation ratio.Secondly,on the basis of the microscopic evaluation indicator,the fluid velocity deviation ratio using the enhanced wall function and SST k-ω physical model is minimal,and the value of microscopic evaluation indicator is 2.095%.Thirdly,the weight coefficients of macroscopic evaluation indicator and microscopic evaluation indicator are 0.6 and 0.4,respectively.Evaluating two indicators comprehensively,the value of comprehensive evaluation indicator using the enhanced wall function and SST k-ωphysical model is minimal,which is 2.031%.Further verifying the precision of the comprehensive evaluation indicator model,the comprehensive evaluation indicator between the measure value and numerical simul

关 键 词：滴灌灌水器 模拟精度 流量 流速 评价指标 

分 类 号：S275.6[农业科学—农业水土工程]