Rotorcraft Brownout Aerodynamic Analysis and Flight Simulation

A critical operational problem for current Army rotorcraft is the prediction of landing conditions in a sand/dust/snow laden environment where rotorwash picks up loose ground cover leading to a condition of obscured visibility known as "brownout". The proposed effort will develop both a comprehensive analysis and flight simulation tool able to predict the magnitude and distribution of visibility difficulties associated with brownout. An accelerated timetable is projected by integrating and enhancing several state-of-the-art technologies already in place at Continuum Dynamics, Inc. (CDI). These technologies include: CDI's CHARM full-span free-vortex wake model and fast panel fuselage/ground surface model for general rotorcraft flow fields in steady and transient flight including a real-time free wake option for flight simulation applications; CDI's Army-accredited LDTRAN/CB model of particle uptake, entrainment and transport; an enhanced version of the Army's GenHel flight simulation software; and CDI's VRML/X3D out-the-window display technology that already supports the rendering of visual obscuration. Building quickly on these validated technologies, it is expected that a prototype rotorcraft brownout analysis and flight simulation tool can be completed in Phase I, followed by a significant expansion of features, validation and packaging in Phase II including a real-time flight simulation capability.