Turbulent drag of ridge-type surface structures

我们目前的预测能力发生在粗糙表面的湍流摩擦损失包括很大的不确定性，特别是大规模的非均匀表面。本建议的脊型表面结构是一个模型系统的展向粗糙度的变化，在文献中被广泛采用。表面安装的脊沿顺流流动方向定向。我们小组之前的工作表明，这种简单的表面几何形状会导致复杂的阻力行为，可以根据不同的阻力机制进行分类。本项目的目的是调查这些阻力制度是否可以复制与不同类型的脊几何形状和流动现象可以链接到不同的阻力制度。我们设想，所获得的见解可以提供重要的理解，为非均匀粗糙表面的预测粗糙度工具的进一步发展。

Our present predictive capabilities for friction losses occurring in turbulent flow over rough surfaces include large uncertainties, especially for large scale inhomogeneous surfaces. The ridge-type surface structures of the present proposal are a model system for a spanwise variation in roughness that is widely employed in literature. The surface mounted ridges are oriented in streamwise flow direction. Previous work by our group has revealed that this simple surface geometry results in a complex drag behavior that can be classified by different drag regimes. The present project aims at investigating whether these drag regimes can be reproduced with different types of ridge geometries and which flow phenomena can be linked to the different drag regimes. We envisage that the obtained insights can provide important understanding for the further development of predictive roughness tools for inhomogeneous rough surfaces.