【摘要】：繞流葉片的非穩(wěn)態(tài)流動及其尾跡渦結構是誘發(fā)水力機械振動的主導因素。以橫向布置的一對平板葉柵為研究對象,基于LES計算雷諾數在4.8×104下的三維繞流流場,分析繞流流場渦演化結構、升阻力及壓力脈動等特性,以揭示尾跡干涉下平板繞流的流場結構及其激勵機制。結果表明:該雷諾數下,單平板繞流平板表面存在錯列布置的發(fā)卡渦結構,繞流尾跡呈現出高度的三維特性;雙平板葉柵繞流狀態(tài)下,上、下游平板間的間隙流動結構有明顯抑制上游平板表面渦結構演化的作用;平板受力在模式H和模式L之間不斷切換,且升力波動的幅值隨阻力的增大而增大,尾跡干涉下下游平板受力的模式切換頻率升高,升力波動幅值也增大;平板表面壓力脈動的主要激勵源為平板尾渦脫落。尾跡干涉下平板繞流及受力分析,可為水力機械葉片尾跡干涉下的流動主動控制提供參考。
[Abstract]:The unsteady flow around the blade and its wake vortex structure are the leading factors to induce the hydro-mechanical vibration. Taking a pair of transversely arranged flat cascade as the research object, the three-dimensional flow field around Reynolds number at 4.8 脳 10 ~ 4 is calculated based on LES, and the characteristics of vortex evolution structure, lift resistance and pressure pulsation around the flow field are analyzed. In order to reveal the flow field structure and excitation mechanism of the plate flow under wake interference. The results show that there is a staggered hairpin vortex structure on the surface of a single plate flow around the Reynolds number, and the wake of the flow around the plate presents a high three-dimensional characteristic. Under the condition of double plate cascade flow, the gap flow structure between upstream and downstream plates can obviously inhibit the evolution of vortex structure on the upstream plate surface. The amplitude of lift fluctuation increases with the increase of resistance, and the mode switching frequency of downstream plate forces increases under wake interference, and the amplitude of lift fluctuation increases. The main source of pressure pulsation on plate surface is plate wake shedding. The flow around the plate under wake interference and its force analysis can provide a reference for the active control of the flow under the wake interference of the blade of hydraulic machinery.
【作者單位】： 江蘇大學能源與動力工程學院;
【基金】：國家自然科學基金項目(51576090) 江蘇高校優(yōu)勢學科建設工程項目
【分類號】：TV136
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本文編號：2368199