Classroom 2, Sanderson Building
Boundary layer velocity profiles are commonly employed to characterise thin film flows. However, these profiles inherently overlook the crucial zero tangential stress condition, as they typically assume a flat film — a justified approximation except in proximity to critical points, such as locations at which jumps, and film disintegration occur. In this study, we demonstrate that accounting for the zero tangential stress condition yields criticality conditions and retrieves previously phenomenological results, notably the disintegration radius of thin axisymmetric liquid sheets and the radius of circular hydraulic jumps. Our findings shed light on the significant influence of tangential stress in thin film flows and how they couple with surface tension its impact on critical phenomena. Most importantly, in thin film flow, how surface tension influences the velocity profile. Our results challenges the notion that the in both hydrostatics and Hydrodynamics the influence of surface tension is fully contained in Laplace pressure. I will present a comprehensive examination that combines experimental evidence and novel theoretical insights, shedding new light on the fundamental aspect of interfacial flows.
Rajesh Bhagat is a Royal Academy of Engineering Research Fellow at the Department of Applied Mathematics and Theoretical Physics (DAMTP), and a Fellow of Mathematics at Queen’s College Cambridge. His Mair research interests are in the area of Interfacial flows, Building ventilation flows, and airborne disease transmission.