有压管道瞬变流的非恒定摩阻模型改进  

Improvement of unsteady friction model of transient flow in pressurized pipeline

作　　者：黄海 郭鹏程[1,2] 颜建国 徐燕 李江 HUANG Hai;GUO Pengcheng;YAN Jianguo;XU Yan;LI Jiang(School of Water Resources and Hydroelectric Engineering,Xi’an University of Technology,Xi'an 710048,China;State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048,China;Xinjiang Cold and Arid Regions Water Resources and Ecological Water Engineering Research Center(Academician Workstation),Urumqi 830000,China)

机构地区：[1]西安理工大学水利水电学院,西安710048 [2]西安理工大学省部共建西北旱区生态水利国家重点实验室,西安710048 [3]新疆维吾尔自治区寒旱区水资源与生态水利工程研究中心(院士专家工作站),乌鲁木齐830000

出　　处：《农业工程学报》2024年第8期80-89,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(51839010);陕西省创新能力支撑计划资助(2024RS-CXTD-31);陕西高校青年创新团队(2020-29);新疆水专项(2020.C-001)。

摘　　要：有压管道流动系统运行中经常发生水锤现象,极易导致爆管甚至人员伤亡,因此准确预测有压管道内的水锤现象对于保证系统安全运行具有重要意义。在有压管道内的水锤模拟中,以ZIELKE摩阻模型为代表的基于加权函数的非恒定摩阻模型能够描述有压管道瞬变流中的摩阻效应,但存在计算效率低下的问题。为提高计算效率,该研究提出了“先分段,后整体”的两阶段最小二乘拟合方法,建立了包含19个指数项的近似加权函数,并与已有近似加权函数进行对比,同时开展关阀水锤试验,对比了建立的摩阻模型与已有模型的计算效率和精度。结果表明,该研究建立的近似加权函数能够很好地拟合ZIELKE加权函数,其与ZIELKE加权函数的相对百分比误差近似为0;且其适用范围更宽,能够对无量纲时间在t∈[10-9,∞)范围内的非恒定流进行有效模拟。在计算精度方面,建立的模型与ZIELKE模型在阀门和中点处水头的最大相对百分比误差较小,分别为0.17%和0.15%,与URBANOWICZ模型的表现基本相同;在计算效率方面,建立的模型能够使ZIELKE模型计算效率提升约90%,能够使URBANOWICZ模型计算效率提升约30%。该研究建立的模型在适用范围、计算精度和计算效率方面具有较好的综合表现,能够在保证较宽适用范围和较高计算精度的前提下,提升计算效率。研究可为有压管道瞬变流的准确高效模拟提供理论支撑与参考。Water hammer can often occur in a pressurized pipeline flow system,leading to the pipeline explosions and even casualties.Therefore,it is of great significance to accurately predict the water hammer in the pressure pipelines for the safe operation.Among them,the weighting function-based(WFB)unsteady friction can be represented by the ZIELKE model in the simulation of water hammer,in order to effectively describe the frictional effects in the transient flow.However,the flow rates are required from all previous time steps at each time.In computational efficiency,the ZIELKE weighting function has been utilized to approximately sum a finite number of exponential terms,and then combine with the recursive formulas for the unsteady friction terms.But,the existing approximation models have also been limited to the low range of applicability or high computational costs.In this study,a two-stage least squares fitting(TSLSF)has been introduced to simulate the unsteady friction of transient flow in the pressurized pipeline.The initial parameters were obtained to fit the segmentation-based least squares segmentation of the ZIELKE weighting function in dimensionless time.After that,the new approximate weighting function was followed by a global least square fitting over the entire dimensionless time.Finally,19 exponential terms were included in the TSLSF approximate weighting function.The TSLSF approximate weighting function was better fitted the ZIELKE weighting function than before,indicating the relative percentage error close to 0.Moreover,a broader range of applicability was also achieved to effectively simulate the unsteady flows.The experiment of water hammer was carried out in a reservoir-pipeline-valve system,in order to compare the computational efficiency and accuracy of the TSLSF friction model with the existing WFB.The computational accuracy of TSLSF model was closely aligned with the ZIELKE in the pressure wave curves at the midpoint and valve.Furthermore,the maximum relative percentage errors of the pressure hea

关 键 词：瞬变流 水锤 管道 非恒定摩阻模型 加权函数 

分 类 号：TV134.1[水利工程—水力学及河流动力学]