Many natural and industrial flows of granular materials appear fluid like. You may think for example of the flow of grains from a silo, granular avalanches on the surface of sand dunes or the flow of ore from a conveyor belt just before the ore settles to form a pile. In these cases the individual particles interact and exchange momentum through collisions. This is similar to the situation in an ideal gas. However molecular collisions are conservative and granular collisions are not. The dissipative nature of granular collisions manifests itself in the fact that the fluid like behavior ceases almost instantaneously after the grains settle in a static pile as mentioned above in the conveyor belt example. Once permanent inter-granular contacts have been established the granular material behaves solid like. While the collisional or kinetic and the quasi static granular flow regimes are well understood, there exists no self consistent theory which is valid over the whole flow regime.

The PhD candidate will familiarize him/herself with the state of the art in granular flow modelling, generalize the theory proposed by S Savage (SB Savage (1998) Analyses of slow High-concentration flows of granular materials (J. Fluid Mechanics, 377, pp. 1-26) from 2 to 3D, implement the theory into the ESSCC finite element code Finley, compare computer simulations based on the implemented theory with existing experimental results of granular flows and simulate a range of scientifically and industrially relevant 3D flows.

The candidate will be supervised by Professor Hans Muhlhaus. For further information please contact Hans Muhlhaus.