Francisco Fidelis Kisuka

Granular flows are characterised by particle interactions that involve sliding and collisions. In such events, heat is generated from friction and plastic deformation. Despite the importance of such self-heating mechanisms, our understanding of the fundamental principles of heat generation from friction and plastic dissipation is still limited. This work explores this problem at the particle level for oblique impacts between a spherical particle and a rigid substrate. In the first part, theoretical models and a finite element method (FEM) model are used to predict the amount of heat generated and contact temperatures at various impact angles. The theoretical and the FEM models are in good agreement for all impact cases considered. A parametric study of the influence on heat generation and temperature distributions is also carried out. It is shown that the temperature profiles are dependent not only on the amount of the generated heat but also on the material's thermal properties, such as thermal conductivity and specific head capacity. Apart from a good insight into heat generation during oblique impacts, this study also identifies simple theoretical solutions that can be used in other numerical tools, such as discrete element methods, for studying heat generation problems in bulk granular flows.