论文标题
使用仿生鱼尺度阵列的过渡延迟
Transition Delay Using Biomimetic Fish Scale Arrays
论文作者
论文摘要
水生动物已经制定了有效的策略，以减少长时间的身体拖累。在这项工作中，研究了鱼类量表对边界层中层流向扰动的过渡的影响。在典型的重叠排列中的仿生鱼尺度阵列放在低扰动层流水通道的平板上。 Tollmien-Schlichting（TS）波的受控激发触发了向湍流的过渡。发现TS波可以用板上的尺度衰减，从而产生流向条纹。结果，相对于不受控制的参考案例，过渡位置在下游方向上大大延迟了55％。这对应于理论上的阻力减少约27％。因此，我们假设鱼鳞可以稳定层状边界层并防止早期过渡，从而减少摩擦阻力。该技术可以用作层流控制均值的生物启发的表面。
Aquatic animals have developed effective strategies to reduce their body drag over a long period of time. In this work, the influence of the scales of fish on the laminar-to-turbulent transition in the boundary layer is investigated. Arrays of biomimetic fish scales in typical overlapping arrangements are placed on a flat plate in a low-turbulence laminar water channel. Transition to turbulence is triggered by controlled excitation of a Tollmien-Schlichting (TS) wave. It was found that the TS wave can be attenuated with scales on the plate which generate streamwise streaks. As a consequence, the transition location was substantially delayed in the downstream direction by 55% with respect to the uncontrolled reference case. This corresponds to a theoretical drag reduction of about 27%. We thus hypothesize that fish scales can stabilize the laminar boundary layer and prevent it from early transition, reducing friction drag. This technique can possibly be used for bio-inspired surfaces as a laminar flow control means.
