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不同動態(tài)水壓模式下迷宮流道內(nèi)顆粒物運動特性研究
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中國科學(xué)院西部之光人才培養(yǎng)計劃項目、西北農(nóng)林科技大學(xué)基本科研業(yè)務(wù)費專項資金項目(2014YB061)和“十二五”國家科技支撐計劃項目(2015BAD22B01-02)


Particles Movement Characteristics in Labyrinth Channel under Different Dynamic Water Pressure Modes
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    摘要:

    采用PTV技術(shù),觀測三角函數(shù)、三角、臺階、矩形波形動態(tài)水壓模式下迷宮流道內(nèi)顆粒物的運動情況,分析不同動態(tài)水壓模式下迷宮流道內(nèi)單個顆粒物運動軌跡、運動速度及流體流場,揭示動態(tài)水壓抗堵塞機理。結(jié)果表明:相對于三角、臺階及矩形波形動態(tài)水壓模式,三角函數(shù)波形動態(tài)水壓模式下顆粒物滯留滯止區(qū)內(nèi)的時間最短,顆粒物的沉積概率最小,水流對顆粒物的輸移能力最大;三角函數(shù)波形動態(tài)水壓模式下流道內(nèi)產(chǎn)生的水流波動效應(yīng)不斷沖擊流道滯止區(qū)內(nèi)存在的低速漩渦,加劇了滯止區(qū)水流紊動,進入滯止區(qū)的顆粒物隨水流不斷運動,并對滯留甚至沉積在滯止區(qū)內(nèi)的顆粒物發(fā)生強烈沖擊,使得顆粒物離底懸浮,返回主流區(qū),并迅速通過流道,增大了水流對顆粒物的輸移能力,增強了流道的抗堵塞性能。

    Abstract:

    The movements of tracer particles in a labyrinth channel were observed by using the PIV technique. The pressure was in dynamic modes with trigonometric function, triangular, step and rectangular waveforms. The trajectories, velocity of single particle as well as the overall flow field in the channel were analyzed to reveal the anti-clogging mechanism of dynamic water pressure. The results showed that when compared with constant water pressure, flow rates in the channel under trigonometric function, triangular, step and rectangular waveforms dynamic pressure modes were not decreased significantly. Therefore, effect of dynamic water pressure on water delivery capacity of drip irrigation system was not obvious. Among the different dynamic water pressure modes mentioned above, the trigonometric function type demonstrated the shortest particles residence time in the flow stagnation region. The deposition probability of particles was the lowest under this mode, indicating a better particles transport capacity in the channel. Fluctuation effect generated by the water under pressure of trigonometric function form produced effect on the lowspeed swirl in the stagnation region, and aggravated the turbulence of flow in this region. The turbulent flow was enhanced and the ability to carry the particles retained or even deposited in the stagnation zone was improved. As a result, the particles were suspended from the bottom and returned back to the main flow path. The transport capacity of the flow got strengthened, and the anticlogging performance of the channel was improved.Therefore, the trigonometric function waveform dynamic water pressure model can most effectively improve the anticlogging performance in the labyrinth channel.

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鄭超,吳普特,張林,朱德蘭,趙笑,安伯達.不同動態(tài)水壓模式下迷宮流道內(nèi)顆粒物運動特性研究[J].農(nóng)業(yè)機械學(xué)報,2017,48(3):294-301. ZHENG Chao, WU Pute, ZHANG Lin, ZHU Delan, ZHAO Xiao, AN Boda. Particles Movement Characteristics in Labyrinth Channel under Different Dynamic Water Pressure Modes[J]. Transactions of the Chinese Society for Agricultural Machinery,2017,48(3):294-301.

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  • 收稿日期:2016-11-08
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  • 在線發(fā)布日期: 2017-03-10
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