Surface-specific Moody-diagrams: A new paradigm to predict drag penalty of realistic rough surfaces with applications to maritime transport

特定于表面的穆迪图：预测现实粗糙表面阻力损失的新范式及其在海上运输中的应用

• 批准号: EP/P009638/1
• 负责人: Bharathram Ganapathisubramani
• 金额: $ 98.79万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FP009638%2F1
• 关键词: Surface; specific; Moody; diagrams; new

The sea-water that flows over a ship hull forms a turbulent boundary layer that is responsible for the skin-friction drag incurred by the ship. This boundary layer is influenced by the "roughness'' of the hull surface, which increases the drag penalty by up to 80% compared to a smooth surface in some applications. This highlights the urgent need to understand the "roughness'' effects of surface coatings and their degradation on the efficiency, economy and emissions of ship transportation. In this project, we propose a transformative approach where we tackle this pressing problem using three complementary methods. First, we will carry out Direct Numerical Simulations (DNS) of turbulent flow over surfaces that have been obtained from surface scans of various ship hulls. These results will be complemented by laboratory experiments and measurements in a towing tank of flows over replica of the same scanned surfaces. Finally, a DNS-Embedded Large Eddy Simulation (DELES) methodology will be developed and used to predict the influence of realistic topographies on drag.This holistic approach will provide the necessary data to gain fundamental understanding of the flows over such rough surfaces and enable development of a new data-rich paradigm for predicting the effects of roughness. We will specifically focus on maritime transport by developing a new surface-specific Moody-diagram approach that can be used by coatings manufacturers and ship operators to generate a realistic estimate of the drag penalty of coatings and fouling. This information can then be used to make operational decisions such as duration between dry-docking, quality of surface finish when in dry-dock, choice of specific coatings for specific surface finish and the variations in performance during service. This new approach can easily be extended to different sectors and new surface-specific Moody-diagrams can be developed for a whole range of applications including oil, gas and water transport pipelines, aircraft fuselage, trains, propellers etc. This project has financial support from a leading antifouling coatings manufacturer as well as collaborators at the University of Melbourne and the US Naval Academy who share our mutual interest in this research area.

流过船舶船体的海水形成湍流边界层，该湍流边界层是船舶所承受的表面摩擦阻力的原因。该边界层受到船体表面“粗糙度”的影响，在某些应用中，与光滑表面相比，这会使阻力损失增加高达80%。这突出表明迫切需要了解表面涂层的“粗糙度”影响及其对船舶运输效率，经济性和排放的退化。在这个项目中，我们提出了一种变革性的方法，我们使用三种互补的方法来解决这个紧迫的问题。首先，我们将进行直接数值模拟（DNS）的湍流表面已获得从表面扫描的各种船体。这些结果将得到补充的实验室实验和测量在一个拖曳坦克的流动复制品相同的扫描表面。最后，一个DNS嵌入式大涡模拟（DELES）的方法将被开发和使用来预测真实的地形对阻力的影响。这种整体的方法将提供必要的数据，以获得基本的了解这种粗糙表面上的流动，并使开发一个新的数据丰富的范例，用于预测粗糙度的影响。我们将特别关注海上运输，开发一种新的表面特定穆迪图方法，可供涂料制造商和船舶运营商使用，以产生涂料和污垢的阻力损失的现实估计。这些信息可用于做出操作决策，例如干船坞之间的持续时间、干船坞中的表面光洁度质量、特定表面光洁度的特定涂层的选择以及服务期间的性能变化。这种新的方法可以很容易地扩展到不同的部门和新的表面特定的穆迪图可以开发一系列的应用，包括石油，天然气和水的运输管道，飞机机身，火车，该项目得到了一家领先的涂料制造商以及墨尔本大学和美国海军学院的合作者的财政支持，他们在这方面与我们有共同的利益研究领域。

项目成果

Skin-friction measurements in a turbulent boundary layer under the influence of free-stream turbulence

自由流湍流影响下湍流边界层的表面摩擦测量

• DOI: 10.1007/s00348-017-2397-8
• 发表时间: 2017
• 期刊: Experiments in Fluids
• 影响因子: 2.4
• 作者: Esteban L

An alternative floating element design for skin-friction measurement of turbulent wall flows

用于湍流壁流的表面摩擦测量的替代浮动元件设计

• DOI: 10.1007/s00348-018-2612-2
• 发表时间: 2018
• 期刊: Experiments in Fluids
• 影响因子: 2.4
• 作者: Ferreira M

A DNS/URANS approach for simulating rough-wall turbulent flows

模拟粗糙壁湍流的 DNS/URANS 方法

• DOI: 10.1016/j.ijheatfluidflow.2020.108627
• 发表时间: 2020
• 期刊: International Journal of Heat and Fluid Flow
• 影响因子: 2.6
• 作者: Alves Portela F

In-situ turbulent boundary layer measurements over freshly cleaned ship-hull under steady cruising

稳定巡航下新清洁船体的原位湍流边界层测量

• 发表时间: 2017
• 作者: B. Nugroho

Revisiting rough hull drag penalty

重新审视粗糙的船体阻力惩罚

• 作者: B. Nugroho