A numerical model for wind-borne compact debris trajectory estimation: Part 2 – Simulated vertical gust effects on trajectory and mass momentum

Abstract

In a companion paper [1], the trajectory of compact debris was estimated by accounting for the many uncertainties associated with debris flight. Compact debris are objects possessing non-negligible mass but negligible moment of inertia (e.g., a particle-type object); the wind-driven motion of the debris is predominantly controlled by aerodynamic drag with a limited influence of aerodynamic lift or moment. A numerical algorithm for investigating the probability of wind-borne compact debris impacting on the vertical façade of tall buildings was discussed.In this study, the effect of a “sudden” vertical gust on the trajectory of compact objects was analyzed. Since at initial stages of the flight the effect of turbulence may have an influence on the trajectory, a “Küssner-like” Gust model was proposed, incorporated in the loading model and used in conjunction with the equations of the motion. The numerical simulations, accounting for this simulated vertical gust, indicate that the effect of a simplified vertical turbulence scenario may often be neglected for estimating the trajectory of a compact object. Nevertheless, some effect of this simulated gust on “Iso-probability Impact Contours” and “Universal Probability Curve”, described in [1], was observed and quantified.