Scale-resolving simulation to predict the updraught regions over buildings for MAV orographic lift soaring

Urban flow and small unmanned aerial system operations in the built environment

“…The mechanical turbulence generated in the wake of urban structures spans a wide variety of length scales with the largest eddies commensurate with the size of the structure (Marino et al, 2015;Mohamed, Carrese, Fletcher, & Watkins, 2015). Due to the size of these large eddies relative to the characteristic dimensions of sUAS, these eddies can be taken to be effectively stationary relative to the sUAS.…”

“…When flow encounters a building, a bluff body, the disturbed flow can, in general, be partitioned for analysis into four distinct zones: the frontal zone where the flow approaches the building, a zone over the roof, the downwind wake zone, and lateral zones to either side of the building. For both isolated buildings and dense building configurations, it has been observed that disturbed flow exists vertically until a height approximately three times greater than the physical height of the tallest structure (Erell, Pearlmutter, Williamson, & Williamson, 2015;Mohamed, Carrese et al, 2015;Rafailidis, 1997).…”

Towards Autonomous MAV Soaring in Cities: CFD Simulation, EFD Measurement and Flight Trials

“…The computational model was simulated using the general purpose finite volume code ANSYS Fluent Version 15. Only a summary of the method used will be given as details have already been extensively described [3].…”

“…A northerly wind of 3 m/s at a height of 10 m (termed the reference velocity) was introduced via an ABL profile (with synthetic turbulent fluctuations imposed) and the upstream terrain was modeled using an equivalent surface roughness. The validation approach using geometrically simple cases (but not simple resulting fluid flows) is detailed in [3]. The approach followed the guidelines proposed by Blocken [2], whereby assessment and validation of the numerical modelling procedure should be (in the absence of case-specific benchmarks) performed for simpler configurations, the flow features of which show resemblance with the proposed case-study.…”

Bioinspired Energy Harvesting from Atmospheric Phenomena for Small Unmanned Aerial Vehicles

“…The optimal flight trajectories for energy harvesting inspired by albatross flight (that are often called dynamic soaring) were demonstrated by Zhao [8], Bonnin [9], and most recently Liu et al [10]. While a significant amount of work has been done on exploiting longduration atmospheric effects with a flight strategy often called autonomous soaring (for example, the experiment described by Fisher et al [11], Watkins et al [12], Mohamed et al [13] and most recently by Depenbusch et al [14,15]) and dynamic soaring (exploiting spatial gradients), a few theoretical works on exploiting gusts have been performed.…”