权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Fluid dynamic properties of irregular, multi-scale rough surfaces

不规则、多尺度粗糙表面的流体动力学特性

基本信息

批准号：
EP/P004687/1
负责人：
Angela Busse
金额：
$ 12.84万
依托单位：
University of Glasgow
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%2FP004687%2F1
关键词：
Fluid dynamic properties irregular multi

项目摘要

Surfaces roughness affects energy efficiency and maintenance costs in many industrialsectors. Rough surfaces impair the performance of turbomachinery and marine energy harvesting sys-tems. Surface roughness caused by fouling increases the drag of ships and aircraft. An accurate prediction of the impacts of roughness is a prerequisite for the design of resilient systems and the economic scheduling of maintenance cycles for machinery affected by surface roughness built-up e.g. due to surface fouling or erosion. Surface roughness increases fluid dynamic drag and cause a downwards shift in the near-wall velocity profile called the roughness function. The fluid dynamic roughness effect is influenced both by the roughness height and the roughness topography. Engineering rough surfaces with the same roughness height but different topographies can give rise to roughness function values that differ by a factor of four. While the relationship between roughness height and drag is well understood, the relationship between roughness topography and fluid dynamic properties remains unclear, making an accurate prediction of the fluid dynamic properies of a rough surface impossible.In this project, surface simulations methods from tribology will be used to generate realistic randomrough surfaces with specified topographical parameters. Direct numerical simulations of turbulent channelflow over the surfaces will be used to obtain their fluid dynamic properties with the aim to establishrelationships between topographical parameters and quantities such as the fluid dynamic drag, the roughness function and near-wall turbulence intensity levels. The new relationships will enable the development of betterturbulence models for typical industrial computational fluid dynamics simulations that can takesurface topography effects into account. This will provide the basis for a more accurate prediction ofthe impact of roughness in a wide range of engineering systems including the marine energy sector,where bio-fouling and corrosion lead to strong surface roughness effects.

表面粗糙度影响能源效率和维护成本在许多工业部门。粗糙的表面会损害涡轮机械和海洋能量收集系统的性能。污垢引起的表面粗糙度增加了船舶和飞机的阻力。对粗糙度影响的准确预测是设计弹性系统的先决条件，也是对受表面污垢或侵蚀等表面粗糙度影响的机械进行维修周期的经济调度的先决条件。表面粗糙度增加流体动力阻力，并导致近壁速度剖面向下移动，称为粗糙度函数。流体动力粗糙度效应受粗糙度高度和粗糙度形貌的影响。具有相同粗糙度高度但不同地形的工程粗糙表面可能会产生粗糙度函数值相差四倍。虽然粗糙度高度和阻力之间的关系已经被很好地理解，但粗糙度形貌与流体动力特性之间的关系仍然不清楚，因此不可能准确预测粗糙表面的流体动力特性。在这个项目中，摩擦学中的表面模拟方法将用于生成具有指定地形参数的逼真随机粗糙表面。对表面上的湍流通道流动进行直接数值模拟，以获得其流体动力特性，目的是建立地形参数与流体动力阻力、粗糙度函数和近壁湍流强度水平等数量之间的关系。新的关系将有助于为典型的工业计算流体动力学模拟开发更好的湍流模型，这些模型可以考虑表面地形效应。这将为更准确地预测粗糙度在广泛的工程系统中的影响提供基础，包括海洋能源部门，其中生物污染和腐蚀导致强烈的表面粗糙度效应。