Dense inclined flows: Theory and experiments. Quarterly technical progress report, July 1, 1995--September 30, 1995

Rapid, gravity-driven flows of granular materials down inclines pose a challenge to our understanding. Even in situations in which the flow is steady and two-dimensional, the details of how momentum and energy are balanced within the flow and at the bottom boundary are not well understood. Thus we have undertaken a research program integrating theory, computer simulation, and experiment that will focus on dense entry flows down inclines. The effort involves the development of theory informed by the results of simultaneous computer simulations and the construction, instrumentation, and use of an experimental facility in which the variables necessary to assess the success or failure of the theory can be measured. In the present reporting period, we have completed the experiments with the bumpy base consisting of random two-dimensional packings of l nun glass spheres; we have derived boundary conditions for a bumpy frictionless boundary for other than small slip velocities; and we have made numerical studies of hydraulic equations using a simple Lagrangian code that we have developed. We are now in the process of writing the final report and a journal article summarizing our findings