Title of article :
Effect of computer-generated turbulent wind field on trajectory of compact debris: A probabilistic analysis approach
Moghim، نويسنده , , Farid and Caracoglia، نويسنده , , Luca، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2014
A model and numerical algorithm is developed to simulate wind-borne debris trajectories in a fully-developed atmospheric boundary layer wind. The model works in two dimensions and makes use of synthetically-generated turbulence time histories; it accounts for variable mean velocity field with elevation and turbulence. The simulation of a partially coherent wind field was based on the wave superposition method (Di Paola, 1998) . For the simulation of the turbulence field, a simplified approach is proposed. First, turbulence is generated at discrete points located on the “inlet boundary” of the field; second, turbulence is propagated through the field using either Taylor’s “frozen turbulence” hypothesis or a simplified “Eulerian–Lagrangian” formulation. The latter term is used to emphasize that an expression is employed to approximately replicate the features of the Lagrangian turbulence wind spectrum (for high-speed moving objects), even though turbulence is still synthetically generated on a large portion of the field at all times, from an Eulerian point of view. After generating the wind field, the trajectory of compact objects is estimated by means of a point mass dynamic model, converted to state-space form and integrated by fifth-order Runge–Kutta method.
merical model is applied to the study of the risk of impact by wind-borne debris against tall building facades, recently investigated by the authors for uniform non-turbulent wind field only. The analysis is conducted by using the computer-generated wind field to estimate “universal probability curves” (probability-of-impact curves) for compact debris, conditional on the initial distance of the object from the building before takeoff. Both qualitative and quantitative variations are noted in comparison with previous results.
Wind-borne debris , Trajectory estimation , Universal probability curve , Turbulent wind field , Wave superposition method , Taylor’s frozen turbulence hypothesis , “Eulerian–Lagrangian” formulation
Journal title :