The multi-scale challenges of friction, which arise across disciplines at solid-solid and solid-fluid interfaces, have limited the engineering community's ability to describe the process in a deterministic manner. This grant enables the convening of a small workshop to initiate a "cross-fertilization" of methodology between fluid and solid mechanics communities studying this problem at different interfaces and to tackle the grand challenge of the formulation of unified analysis techniques. The small group of attendees will be selected to include broad and diverse participation across the disciplines of fluid mechanics (microfluidics, slip, turbulent boundary layers), solid mechanics (friction, multiscale analysis and material physics) and dynamical systems.
Improved understanding and modeling of the multiple origins of friction form a vital component of technologies aimed at reducing the environmental impact of human development and transportation. The implications for solid-solid interfaces include reduced wear, noise, vibration, etc. and increased transmission efficiency in many applications. At interfaces between fluid flow and solid materials this enhanced understanding holds potential for advances ranging from turbulent skin friction reduction for increased vehicle efficiency, improved models and control of pollutant dispersion by atmospheric winds in urban "rough" environments to advanced understanding of environmental physics and climate phenomena such as ice-field development and glacier melting. The need for significant progress challenges the engineering community both to find interdisciplinary approaches that integrate elements of fundamental solid and fluid mechanics and to develop active control techniques to shape the coupling between friction at the interface and the overall system response in optimal ways.
