当前位置: X-MOL 学术Ocean Eng. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
On the use of synthetic inflow turbulence for scale-resolving simulations of wetted and cavitating flows
Ocean Engineering ( IF 5 ) Pub Date : 2021-04-01 , DOI: 10.1016/j.oceaneng.2021.108860
M. Klapwijk , T. Lloyd , G. Vaz , T. van Terwisga

The Delft Twist 11 Hydrofoil is a common test case for investigating the interaction between turbulence and cavitation modelling in computational fluid dynamics. Despite repeated investigations, results reported for the lift and drag coefficient are accompanied by significant uncertainties, both in experimental and numerical studies. When using scale-resolving approaches, it is known that turbulent fluctuations must be inserted into the domain in order to prevent the flow from remaining laminar around the body of interest, although this has been overlooked until now for the present test case. This work investigates the errors occurring when a laminar inflow is applied for mildly separated or attached flows, by employing the partially averaged Navier–Stokes equations with varying values for the ratio of modelled-to-total turbulence kinetic energy, and with varying grid densities. It is shown that depending on the grid resolution laminar leading edge separation can occur. When turbulent fluctuations are added to the inflow, the leading edge separation is suppressed completely, and the turbulent separation zone near the trailing edge reduces in size. The inflow turbulence has a large effect on the skin friction, which increases with increasing turbulence intensity to a limit determined by the grid resolution. In cavitating conditions the integral quantities are dominated by the shedding sheet cavity. The turbulence intensity has little effect on the pressure distribution, leading to a largely unaffected sheet cavitation, although the shedding behaviour is affected. It is shown that, especially in wetted flow conditions, with scale-resolving methods inflow turbulence is necessary to match the experimental flow field.



中文翻译:

关于使用合成流入湍流进行湿润和空化流的水垢解析模拟

Delft Twist 11 Hydrofoil是一个常见的测试案例,用于研究计算流体动力学中湍流和空化模型之间的相互作用。尽管进行了反复研究,但在实验和数值研究中,所报告的升力和风阻系数的结果都带有明显的不确定性。当使用水垢分解方法时,众所周知,必须将湍流波动插入到区域中,以防止流动保持在目标物体周围的层流,尽管在目前的测试案例中,这至今仍被忽略。这项工作通过采用部分平均的Navier-Stokes方程,对模型的湍流动能与总湍流动能之比采用不同的值,从而研究了将层流应用到轻度分离或附着的流时发生的误差,并具有不同的网格密度。结果表明,根据网格分辨率,可能会发生层流前沿分离。当湍流涨落加到入流时,前缘分离被完全抑制,并且后缘附近的湍流分离区尺寸减小。流入湍流对皮肤摩擦有很大的影响,随着湍流强度增加到网格分辨率确定的极限,皮肤摩擦会增加。在空化条件下,积分量主要由脱落板腔占据。湍流强度对压力分布几乎没有影响,尽管影响了脱落行为,但导致很大程度上不受影响的片状气穴现象。结果表明,特别是在湿流条件下,

更新日期:2021-04-01
down
wechat
bug