【作者】 郭建明；

【导师】 阎庆绂；

【作者基本信息】 太原理工大学 ， 水力学及河流动力学， 2004， 硕士

【摘要】 在许多行业的流体动力系统中，瞬变现象时有发生，全面探索整个系统的瞬变特性，找出其发生强瞬变的内在原因，提出防止和控制手段，是当前面临的重要课题。据此，本文在动力系统综合实验装置上对不同上游水位、运行流量、以及不同的运行管长进行了可调节与非调节工况的实验模拟，通过实验研究和理论分析，提出了瞬变强度系数与容性因子与惯性因子比的概念，主要内容和结论如下：不同流量和上游压头的组合情况下，系统表现出不同的瞬变特性，即而可将瞬变工况大致分为两类：强瞬变和弱瞬变，而瞬变强度可用瞬变强度系数来表示。是否发生强瞬变由系统内在因素决定，即h₀／q（v0）比值决定，比值越小发生瞬变的强度越大，而非调节工况的发生起到了诱导和催化作用。具有较大容积的液体容器具有容性特性，而管系内的运动流体具有惯性特性。本文中上游水箱水位可作为容性因子，管系内流量可作为惯性因子。而h0／q_v0代表了容性因子与惯性因子比值，它决定了系统的瞬变强度。实验研究和分析发现，从发生瞬变的时间来说，在非调节工况发生的同时和经过一段较短的时间，要出现两次强度不同的瞬变，本文称为即时瞬变与延时瞬变，这一新的研究成果，将会深化瞬变特性研究，拓展瞬变特性理论，具有学术意义和实际应用价值。本文还为减小瞬变强度和应继续研究的问题提供了方向。更多还原

【Abstract】 In the fluid dynamic systems of many industries, transient phenomena may occur frequently. So, presently, it is an important task to explore transient properties of the whole systems, find out the reasons that make the transient occur, presenting methods to prevent and control it. Hereby, this paper made experimental imitation in both adjustable and no adjustable operating modes, during which different water levels in the upper reaches, operation flow, and operation lengths in the experimental device were given. After having made experimental researches and theoretical analyses, this paper presented the concepts of transient intensity and the ration of volume factor to inertia factor. The main contents and conclusions are: the systems show the different transient properties when the different flow and pressures in the upper reaches are set. And that, the transient operating mode can be classified as two kinds: strong transient and weak transient. Transient intensity can be denoted by transient intensity coefficient. The inside factor, that is the ratio of ho to qv0 in the systems, is decisive to make the strong transient occur. Moreover, the smaller the ratio, the more intense the transient will be, in which the adjustable operating mode plays an inductive role. The fluid in a great container possesses property; the moving fluid inpipes possesses an inertia property insteadly. In this paper, water level in the upper tank can be seen as capacitive factor, flow in the pipes can be seen as an inertia factor. Furthermore h0/qv0 denotes the ratio of capacitive factor to inertia factor, and it determines the transient intensity. From the experimental researches and analyses, we found that the transient will occur twice at the same time and after a period of time when the no adjustable operating mode occurs, each of which has a different intensity. We name them as simultaneous transient and delayed transient respectively. This new research results will deepen the study on the transient properties and develop the theory of the transient properties. So it possesses science meaning and factual application value. Furthermore, this paper also point out a direction in reducing the transient intensity and those problems which should be studied fatherly.更多还原