隔水管附属管控制流动的离散涡模拟分析

采用离散涡方法对单隔水管和带附属管的隔水管的二维绕流问题分别进行了数值模拟分析.首先对4种不同附属管管数的配置情况进行了模拟,结果表明,除了管数为4、来流角度为45°的情况外,附属管能在一定程度上降低升阻力,并抑制漩涡脱落,在附属管管数较多的情况下,抑制效果更好;然后对附属管管数分别为4和10的2种布局,进行了来流方向的敏感性分析并与实验结果对比,发现多管数对来流方向的敏感性要低得多,相对于单隔水管,10根管能使时均阻力系数和脉动升力系数分别获得约26%和79%的降低.采用离散涡方法,不仅计算时间短,而且模拟结果比较可靠,具有较好的参考价值,丰富了控制隔水管绕流流动的研究手段.

Numerical Simulation of Flow Control of a Riser Attached with Axial-Rod Shrouds Using Discrete Vortex Method

Abstract： In this paper, a two dimensional flow around a riser and the one attached with axial-rod shrouds were investigated using discrete vortex method (DVM) respectively. It is shown that at different shroud numbers, shrouds can suppress the drag and lift coefficients, and vortex shedding to some extent, except for the case of 4 rods number with 45° inflow. The large number of rods achieves better suppression effect. Compared with the results of 10 rods with 4 rods, it is shown that the 10-rod shroud is less sensitive to the inflow direction than the 4-rod shroud. For the 10-rod shroud, both time-averaged drag coefficient and fluctuating lift coefficient are less than those of the corresponding bare cylinder with a reduction up to about 26% and 79% respectively. DVM can be useful for the research of flow of circular cylinder and flow suppression because of its quick, simple, and reliable features.
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