This paper presents the results of flow and turbulence characteristics measured by a down-looking 16 MHz micro acoustic Doppler velocimeter around partially submerged spur dyke founded in a clay–gravel sediment mixture. Velocity and turbulence data were collected at various cross-sections at the wake and upstream sides of the spur dyke within and outside of the scour hole. The longitudinal velocity, turbulence intensities and Reynolds stresses were measured and quantitative analysis was carried out. Very small values of the longitudinal velocity component (negative) were obtained within the scour hole whereas larger values were obtained beyond the scour hole region. Turbulence intensities and Reynolds stresses were larger within the scour hole in the wake zone of the spur dyke. Bursting events, including outward interaction, ejection, inward interaction and sweep, were also analysed around the spur dyke. Quadrant analysis of the velocimeter data showed that the values of outward and inward interaction were higher within the scour hole around the spur dyke compared with the values of ejection and sweep events, while outside of the scour hole, the values of ejection and sweep events were higher than the values of outward and inward interaction events.

中文翻译：

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由粘性沉积混合物形成的丁坝周围的流动特性

本文介绍了由向下看的16 MHz微型多普勒测速仪在黏土-砾石沉积混合物中部分淹没的丁坝周围测得的流动和湍流特性的结果。在冲刷孔的内部和外部，在丁坝的尾流和上游侧的各种横截面处收集速度和湍流数据。测量了纵向速度，湍流强度和雷诺应力，并进行了定量分析。在冲孔内获得了非常小的纵向速度分量（负值），而在冲孔区域之外获得了较大的值。丁坝尾流区的冲刷孔内湍流强度和雷诺应力较大。突发事件，包括向外交互，弹出，内向的相互作用和掠过，也分析了丁坝周围。速度计数据的象限分析表明，与顶冲和扫掠事件的值相比，在丁坝周围的冲刷孔内向外和向内相互作用的值更高，而在冲刷孔之外，喷出和扫掠事件的值分别为高于向外和向内互动事件的值。