Abstract
Investigated in this paper is the coupled fluid–body motion of a thin solid body undergoing a skimming impact on a shallow-water layer. The underbody shape (the region that makes contact with the liquid layer) is described by a smooth polynomic curve for which the magnitude of underbody thickness is represented by the scale parameter C. The body undergoes an oblique impact (where the horizontal speed of the body is much greater than its vertical speed) onto a liquid layer with the underbody’s trailing edge making the initial contact. This downstream contact point of the wetted region is modelled as fixed (relative to the body) throughout the skimming motion with the liquid layer assumed to detach smoothly from this sharp trailing edge. There are two geometrical scenarios of interest: the concave case (C<0 producing a hooked underbody) and the convex case (C > 0 producing a rounded underbody). As C is varied the rebound dynamics of the motion are predicted. Analyses of small-time water entry and of water exit are presented and are shown to be broadly in agreement with the computational results of the shallow-water model. Reduced analysis and physical insights are also presented in each case alongside numerical investigations and comparisons as C is varied, indicating qualitative analytical/numerical agreement. Increased body thickness substantially changes the interaction structure and accentuates inertial forces in the fluid flow.
Highlights
The notion of an object skimming across the surface of a liquid layer is likely to be familiar to many
This work extends the analysis presented in [13] in order to understand and treat a wider range of shapes and scales for the system of non-linear ordinary differential equations (ODEs) that govern the vertical height of the body, its rotation and the extent of the wetted region throughout the skimming process
The analysis presented in this paper follows from the foundational work of [13] on the unsteady two-dimensional interactions that occur in the coupled fluid–body motion of a thin body skimming on a liquid layer
Summary
The notion of an object skimming across the surface of a liquid layer is likely to be familiar to many. Other ice crystals may continue to impact the aircraft, and may impact upon this wetted surface This leads to potentially new and noteworthy dynamics as an interaction occurs between these solid (ice) bodies and the shallow liquid layer. This study investigates the skimming impacts of thin bodies (such as particles or ice crystals) with smooth underbody shapes (as described by a polynomial and with an arbitrary overbody shape, within reason) on a shallow liquid layer. Following this set-up, several analytical results for general underbody shapes are discussed This includes the small-time asymptotic entry condition, conditions for body exit, and insight into the expected effect of increased scaled underbody curvature on the body’s skimming motion.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
