Flow Control with Ink-jet Printed Polymer Surfaces

首要目标是设计各种纹理表面（静态和时间依赖性）制造使用各种聚合物，其中，在活性表面的情况下，是电活性的。纹理表面将采取各种形式：聚合物喷墨印刷可以直接产生尺寸设计用于最大减阻的静态肋阵列。该技术可以扩展到具有电极（例如，石墨）的电活性聚合物（EAP）的印刷，使得肋可针对飞行条件重新配置。因此，可以在飞行中对“智能”肋进行优化，以在整个飞行包线内实现最大减阻，或者调整其配置以考虑任何侵蚀效应，从而大大延长其使用寿命。从长远来看（即作为今后几年工作的一部分），将发展在紊流边界层下驱动展向行波的技术。目前PI小组正在开发的这项技术，已知在低雷诺数下，其减阻效果大约是静态沟槽减阻效果（30%）的三倍。这还有待于在高雷诺数下验证。我们提出的具有嵌入式电致动和控制的连续单片EAP表面的建议在易于制造、低维护和环境鲁棒性方面提供了几个优点，所有这些都对航空领域非常有吸引力。

The overarching goal is to design a variety of textured surfaces (both static and time-dependent) fabricated using a variety of polymers, which, in the case of active surfaces, are electroactive. The textured surfaces will take a variety of forms: polymer ink-jet printing can straightforwardly produce a static array of riblets of dimensions designed for maximum drag reduction. The technique may be extended to the printing of Electroactive Polymer (EAP) with electrodes (e.g. graphite) so that the riblets are re-configurable for the flight condition. Therefore 'smart' riblets may be optimised in-flight for maximum drag reduction throughout the flight envelope, or, their configuration adjusted to account for any effects of erosion, so considerably extending their lifetime. In the longer term (i.e. as part of work in subsequent years), the techniques will be developed to drive spanwise travelling waves beneath the turbulent boundary layer. This technique, currently under development in the PI's group, is known to lead to drag reductions roughly three times that possible with static riblets ( 30%) at low Reynolds numbers. It has yet to be verified at high Reynolds numbers. Our proposal of a continuous monolithic EAP surface with embedded electrical actuation and control offers several advantages in terms of ease of manufacture, low maintenance and environmental robustness, all of which are very attractive to the aeronautical sector.