Valve-induced flow characteristics were often concerned in many fluid transportation and control industries. In this paper, the eccentric jet-flow characteristics induced by a gate valve have been studied by considering the influence of valve opening regulation. The experimental setup of monitoring the downstream pressures along the pipeline was developed, and corresponding numerical simulation was employed. The downstream-monitoring pressure distribution caused by valve opening regulation was investigated to verify the flow simulation. The generation mechanism of eccentric jet-flow was revealed as a strong pressure gradient caused by the throttling effect at the valve throat. It was found that the eccentric jet-flow evolved in the pipeline was accompanied by shearing vortices, extremely under a small valve opening. The pressure and axial velocity distributions at various downstream cross-sections of the eccentric jet-flow evolving in the pipeline were analyzed. The axial velocities on four monitoring lines in downstream cross-sections were extracted, and the radial location of the maximum axial velocity was derived to assess the eccentric characteristics of jet-flow. A dimensionless parameter of velocity eccentric ratio was introduced to quantify the eccentric intensity of the evolving jet-flow in the downstream pipeline, and its correlation with the pipeline length could be adequately expressed by a natural decreasing exponential curve via fitting analysis. By virtue of that correlation, the critical pipeline length was proposed that can be used as the judgment to the terminal of the eccentric jet-flow evolving in the downstream pipeline. This study was helpful to characterize the valve-induced flow characteristics in scientific research and provide useful insight into fluid and mechanical engineering.

阀门引起的流动特性在许多流体运输和控制行业中经常受到关注。在本文中，研究了闸阀引起的偏心射流特性，并考虑了开阀调节的影响。建立了监测管道下游压力的实验装置，并进行了相应的数值模拟。研究了由阀门开度调节引起的下游监控压力分布，以验证流量模拟。偏心喷射流的产生机理显示为由阀喉处的节流作用引起的强压力梯度。结果发现，在管道中产生的偏心喷射流伴随着剪切涡流，在很小的阀门开度下非常明显。分析了管道中偏心射流下游各横截面的压力和轴向速度分布。提取下游横截面上的四条监测线的轴向速度，并推导出最大轴向速度的径向位置，以评估射流的偏心特性。引入了一个无量纲的速度偏心率参数来量化下游管道中不断发展的射流的偏心强度，并通过拟合分析通过自然减小的指数曲线来充分表达其与管道长度的相关性。借助于这种相关性，提出了临界管线长度，可以用作对下游管线中偏心喷射流末端的判断。