The modeling of bombardment ejections, as they affect the uplift of dust particles and the formation of a brownout dust cloud generated by a rotorcraft in ground effect operations, is discussed. Bombardment ejections take placewhen a previously suspended particle in the flow collides with a sediment bed and ejects many more particles, leaving a crater behind. A model, based in part from research in aeolian sediment transport, was developed to better represent the mechanisms of bombardment-induced particle ejections during rotorcraft brownout conditions. This method was then coupled to a Lagrangian solver for the rotorflow and a Lagrangian particle dynamics simulation. It isshown how bombardment can play a critical role in the uplift and entrainment of smaller-sized particles from the underlying bed below a rotor. In particular, it is shown how the rotor blade tip vortices and/or regions offlow recirculation near the rotor can eject many particles by bombardment, resulting in the rapid development of intense dust clouds. The formation of vortex wake bundling ahead of the rotor disk was shown to provide the conditions particularly ripe for the ejection and uplift of large quantities of dust particles by means of bombardment mechanisms.
Modeling of bombardment ejections in the rotorcraft brownout problem
Modellierung der Staubpartikeldynamik von Drehlüglern im Bodeneffektbereich
AIAA Journal ; 51 , 4 ; 849-866
2013
18 Seiten, 22 Bilder, 58 Quellen
Aufsatz (Zeitschrift)
Englisch
Modeling of Bombardment Ejections in the Rotorcraft Brownout Problem
Online Contents | 2013
|Discrete Blade Model for Rotorcraft Brownout
AIAA | 2011
|Rotor Configurational Effect on Rotorcraft Brownout
British Library Conference Proceedings | 2010
|Discrete Blade Model for Rotorcraft Brownout
British Library Conference Proceedings | 2011
|