本文選題：非恒定流 + 低濃度�。� 參考：《水科學進展》2017年03期

【摘要】：管道中固液兩相流水擊對管道和輸送系統(tǒng)可能產(chǎn)生嚴重的破壞,而固液兩相在這種非恒定流中的運動特性是計算最大水擊壓力變化的重要依據(jù)。采用粒子圖像測速技術(shù)(Particle Image Velocimetry,PIV),通過試驗研究水擊發(fā)生時,水平圓管中不同平均流速、顆粒粒徑條件下,流體介質(zhì)和粗顆粒在管道斷面的速度分布以及粗顆粒跟隨性的變化規(guī)律。研究結(jié)果表明:(1)在水擊發(fā)生的不同時刻,圓管流中粗顆粒的流速在管道斷面分布呈不規(guī)則的拋物線型分布,主要表現(xiàn)為靠近管道壁面底部的顆粒流速略小于靠近管道頂部流速,當顆粒粒徑大于1.5 mm,平均流速小于2.5 m/s時,粗顆粒表現(xiàn)出明顯的沉降特性;(2)粗顆粒的跟隨性與顆粒受力有密切關(guān)系,其中顆粒速度與流體速度的變化量是影響顆粒受力的重要參數(shù);(3)基于試驗數(shù)據(jù)擬合得到了水擊條件下粗顆粒跟隨性系數(shù)k的經(jīng)驗公式,并分析了顆粒粒徑、管道直徑、兩相流平均流速以及水擊發(fā)生時間等不同參數(shù)對粗顆粒跟隨性系數(shù)的影響,公式計算值與實測值之間的誤差在5%以內(nèi)。
[Abstract]:The solid-liquid two-phase flow impingement may cause serious damage to the pipeline and transportation system, and the motion characteristics of the solid-liquid two-phase in this unsteady flow are the important basis for calculating the maximum water hammer pressure change. Particle Image velocimetry technique is used to study the velocity distribution of fluid medium and coarse particle in pipeline section and the variation of coarse particle following property under the condition of different average velocity of velocity and particle size in horizontal circular pipe during the occurrence of water hammer. The results show that at different times of water hammer, the velocity distribution of coarse particles in the pipe flow is irregular parabola distribution, which mainly shows that the velocity of particle near the bottom of the wall of the pipe is slightly lower than that near the top of the pipe. When the particle size is larger than 1.5 mm and the average velocity of velocity is less than 2.5 m / s, the coarse particle has obvious subsidence characteristics. Among them, the variation of particle velocity and fluid velocity is an important parameter affecting the force of particles. Based on the experimental data fitting, the empirical formula of the coefficient k of coarse particle following under water hammer condition is obtained, and the particle size and pipe diameter are analyzed. The effect of different parameters such as the average velocity of two-phase flow and the time of water hammer occurrence on the coarse-particle follow coefficient is found. The error between the calculated value and the measured value is less than 5%.
【作者單位】： 中央民族大學環(huán)境系;
【基金】：國家自然科學基金資助項目(51339008;51209238)~~
【分類號】：TV134

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