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目的是研究在隧道施工中有限空间附壁射流运动的规律 ,通过大量的试验研究并结合理论分析 ,得出如下结论 :在有限空间内 ,附壁射流的流动区域可分成 3部分 :附壁射流区、回流区和涡流区 ;有限空间附壁射流边界近似为直线 ,射流扩散角约为 7.6 7°;在射流的初始段和主体段流动都具有相似性 ;有限空间附壁射流的断面最大速度沿程衰减 ,且比半无限空间内衰减得快 ;有限空间附壁射流回流区长度随风管出口流量的增加而增长 ,并给出了计算公式。
The purpose of this study is to study the law of the motion of the Coanda jet in a limited space in the tunnel construction. Through a large number of experimental studies and theoretical analysis, the following conclusions are drawn: In a limited space, the Coanda Jet flow area can be divided into three parts: The boundary of the Coanda jet in a finite space is approximately a straight line with a jet divergence angle of about 7.67 °. It has similarities in both the initial section and the main section of the jet. The maximum section velocity of the Coanda jet in a finite space Which attenuates along the way and decays faster than the semi-infinite space. The length of the recirculation zone of the Coanda jet in limited space increases with the increase of the duct exit flow rate, and the formula is given.