考虑不确定性因素的弹性管道水锤模型及实验验证
WATER HAMMER MODEL FOR ELASTIC PIPELINES CONSIDERING UNCERTAINTY FACTORS AND EXPERIMENTAL VALIDATION
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摘要: 在长距离引调水、城市供水等有压输水管道, 系统启停和工况切换等均会引起水锤现象, 导致管线结构破坏甚至爆管现象, 因此精准高效水力瞬变计算对于系统水力安全、智慧调控至关重要. 然而, 现有的水力计算主要是基于传统的弹性水锤理论, 忽略且低估了不确定性因素对能量耗散和水锤压力的衰减效应. 针对弹性管道水锤问题, 提高计算的精确性和可靠性, 考虑实际管道中难以用机理表达的不确定因素, 包括流体的轴向运动、管道锚固约束、流体惯性效应等, 提出两种适用于弹性管道的水锤模型: 广义Kelvin-Voigt模型与Zielke动态摩阻结合的耦合模型、基于广义Kelvin-Voigt模型的水锤模型, 可通过时域全波形反演方法对蠕变函数进行参数率定. 为了验证本文模型的正确性, 搭建了水锤模型实验台. 结果表明, 耦合模型可有效提高弹性管道水锤瞬态模拟的准确性, 但其效率较低; 而广义Kelvin-Voigt模型, 计算模拟与蠕变函数反演的计算效率大幅增加, 且仍然能够有较高的精度, 通过误差分析可知, 得到的蠕变函数对同一管线系统中其余的实验工况依然适用. 因此, 为水锤计算提供了一种精准、高效的计算方法.Abstract: In pressurized water transmission pipelines such as long-distance water diversion and urban water supply systems, operational events such as system start-up, shutdown, and transitions can induce water hammer effects, leading to pipeline structure damage and even pipe bursts. Therefore, accurate and efficient hydraulic transient calculation is crucial for system hydraulic safety and intelligent regulation and control. However, the existing hydraulic calculations are mainly based on the traditional elastic water hammer theories, which tend to overlook and underestimate uncertainties related to energy dissipation and pressure attenuation. In addressing the issue of water hammer in elastic pipelines and aiming to enhance the precision and reliability of computations, this study considers uncertainties that are difficult to express in actual pipelines, including the axial movement of the fluid, the anchoring constraints of the pipeline, and the inertial effects of the fluid. Two water hammer models tailored for elastic pipelines are proposed: a coupling model integrating the generalized Kelvin-Voigt model with from the Zielke unsteady friction model, and a water hammer model based on the generalized Kelvin-Voigt model. Both methods allow for parameterization of creep functions through time-domain full waveform inversion methods. In order to substantiate the accuracy of the models discussed in this paper, an experimental setup was meticulously assembled to simulate the water hammer phenomenon. The results show that the coupled model can effectively improve the accuracy of transient simulation of water hammer in elastic pipelines, but its efficiency is relatively low. In contrast, the generalized Kelvin-Voigt model significantly increases the computational efficiency of both the simulation and the inversion of creep functions, while still maintaining high accuracy. Through error analysis, it can be concluded that the derived creep functions are applicable to other experimental conditions within the same pipeline system. Therefore, this study provides a precise and efficient computational approach for water hammer analysis.