Research Initiation Awards: Study of Thermal Phenomena at Interfaces

薄膜等固体表面的粗糙度测量 和机械加工的金属，在微米和纳米尺度上显示， 几十年来， 长度刻度。 类似的特征在 湍流界面 这种无序的结构 强烈影响界面处热现象。 先前 对这种界面处的热现象的研究 传统上要么过于简化理想化， 光滑的界面或诉诸经验和半- 实证分析方法。 这种身体上的缺乏 对这种现象的理解主要是由于 来量化这些结构中的无序。 本研究 建议使用分形几何的新概念， 理解并描述 无序的表面 这种表征量化了 在一定范围内的每个长度尺度上的表面结构 限制. 这一点在提供关键 深入了解热现象与 在相关长度尺度上的界面。 的初步研究 在接触电导中应用分形解释了 之前的一些实验结果。 基于这些 令人鼓舞的前景，这项研究建议使用分形， 研究科学和工程中界面热现象， 工程重要性，如接触电导，摩擦 加热和辐射与表面的相互作用。

Roughness measurements of solid surfaces, such as thin films and machined metals, at microscales and nanoscales show that the surfaces are rough and disordered over several decades of length scales. Similar features have been observed in turbulent fluid interfaces. Such disordered structures strongly influence thermal phenomena at interfaces. Previous studies on thermal phenomena at such interfaces have conventionally made either oversimplifying idealizations of smoothness of an interface or resorted to empirical and semi- empirical methods of analysis. This lack of physical understanding of the phenomena was mainly due to an inability to quantify the disorder in these structures. This study proposes to use the novel concepts of fractal geometry to understand and characterize the fundamental nature of disordered surfaces. Such a characterization quantifies the structure of surfaces at every length scale within certain limits. This is particularly important in providing key insight into the interactions of thermal phenomena with interfaces at relevant length scales. Preliminary studies on applying fractals in contact conductance have explained several previous experimental results. Based on these encouraging prospects, this study proposes to use fractals to study interfacial thermal phenomena of scientific and engineering importance such as contact conductance, frictional heating, and interactions of radiation with surfaces.