利用超疏水表面Leidenfrost现象实现可持续的湍流减阻

本项目致力于通过结合超疏水表面技术和Leidenfrost现象来探索一种可持续湍流减阻的新方法。我们将以实验为基础结合分子动力学模型来建立超疏水表面在湍流边界层中加热汽化条件下的动力学研究框架。主要任务包括制备具有多尺度结构或润湿性异质模式的超疏水表面；研究相对低沸点下的超疏水表面的沸腾汽化的传热条件；测量由相变传热产生的气泡或气膜在超疏水表面上引起的减阻，并探索减阻与湍流边界层内流场结构变化的联系。这项基础研究将对具有不同润湿性和相变模式的微纳米结构化表面上的湍流边界层中的流动提供更多定量预测，并提供控制热流条件的信息。研究在超疏水表面上的流体力学和传热机理将指导我们开发新型材料以实现可持续的湍流减阻。由于产生Leidenfrost现象所需要的热量可以通过回收船舶和水下航行体的引擎废热来提供，本项目所探索的新型减阻方法不仅具有很高的学术价值，也具有很好的应用前景。

We propose a new approach to achieve sustained drag reduction in a turbulent flow by leveraging the slip flow on superhydrophobic surfaces and the stable vapor layer generated by Leidenfrost phenomenon. We will utilize combined approaches based on experimental and computational fluid dynamics to establish a research frame work for Leidenfrost superhydrophobic surfaces in turbulence flows. The main tasks include the development of hierarchical and heterogeneous superhydrophobic surfaces using scalable and low-cost manufacturing methods; investigation of nucleation and formation of vapor layers on the developed superhydrophobic surfaces under relatively low boiling points; the characterization of the slip flow and friction drag on the developed superhydrophobic surfaces in turbulent flows using our novel drag measurement system in a water tunnel. This fundamental study will provide more quantitative predication of the flow in the turbulent boundary layer on a nano/microstructured surface with different wettability and in the phase change mode, and offer better control of the flow structures and thermal conditions. The broader potential of this effort is to harness these fundamental mechanisms to develop novel materials with proper hydrodynamic and thermal control methods for sustained drag reduction.