A stochastic model for the aerodynamics of irregularly shaped gravel

Md Safwan Ahsanullah, Clemson University
Nigel Kaye, Clemson University

6th American Association for Wind Engineering Workshop (online)

Clemson University, Clemson, SC, USA

May 12-14, 2021


Damage from hurricanes hitting the U.S. between 1980 and 2018 totaled $862 billion (NHC). Post-storm investigations show wind-borne debris is a major contributor to total economic loss. This paper investigates the flight of compact wind-borne debris which has previously only been treated as spherical, ignoring lift forces and shape irregularity, resulting in a two-dimensional flight. However, the trajectory of a piece of gravel is not two-dimensional as its orientation changes during flight, altering the drag force and generating lift forces. This study proposes a stochastic model to resolve some key aspects of the trajectory due to the change in orientation of the debris particle during its flight. The model shows good agreement with experiments. Improved modeling of compact debris will improve our understanding of the risk of damage from windborne debris and enable improved mitigation measures resulting in more resilient communities.