The flow around the so-called HSVA Tanker hull, experimentally studied by Dr. J. Kux [1] at the Institute of Shipbuilding in Hamburg, is considered by the hydrodynamical community as one of the best documented testcases among all the available experimental ship flow databases. Dspite the relative geometric simplicity of the body, the flowfield around this hull is the result of many complicated features involving convergence and divergence of streamlines, a strong thickening of the boundary layer due to rapid changes in cross-sectional shape leading to the development of an intense longitudinal vortex which is slowly relaxed in the wake at large distances downstream from the ship. A more accurate understanding of the flow is provided by the analysis of the limiting streamlines (Figure 1 from [1]). This figure indicates the existence of two lines of convergence located in the aftpart of the hull. the first S-shaped line delimits a vertical wall flow region and a limited zone of flow reversal. The second line of convergence is almost rectilinear and situated slightly above the keel plane of symmetry. It indicated the existence of a region characterized by a large normal velocity which, in that case, is correlated with the development of an intense longitudinal vortex. Figure 2 from [1] shows the axial velocity contours at x/L=0.978. It enables a complementary interpretation of the print provided by the previous figure. The longitudinal velocity contours are characterised by a "hook" shape in the central part of the wake illustrating the interaction between the velocity and vorticity fields, the longitudinal isovels being significantly distorted by the longitudinal vorticity.
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机译：汉堡造船研究所的J. Kux博士[1]通过实验研究了所谓的HSVA油轮船体周围的水流，被流体力学界视为所有可用实验船流中记录最充分的测试案例之一。数据库。尽管船体的相对几何简单性，但船体周围的流场是许多复杂特征的结果，这些特征包括流线的会聚和发散，由于横截面形状的快速变化而导致边界层的强烈增厚，从而导致流线型的发展。强烈的纵向涡流，该涡流在尾流中在船下游较远处缓慢释放。通过分析极限流线可以更准确地了解流量（[1]中的图1）。该图表明位于船体后部的两条会合线的存在。第一条S形线界定了垂直壁流动区域和有限的逆流区域。会聚的第二条线几乎是直线的，位于龙骨对称平面的上方。它表明存在一个以大法向速度为特征的区域，在这种情况下，该速度与强烈的纵向涡旋的发展有关。 [1]中的图2显示了x / L = 0.978时的轴向速度轮廓。它可以对上图提供的打印内容进行补充解释。纵向速度轮廓的特征是在尾流的中心部分呈“钩”形，说明了速度场与涡旋场之间的相互作用，纵向等静线因纵向涡旋而明显变形。
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