Bow Wave Effect in Probe and Drogue Aerial Refuelling

A wide range of UAV applications has been identified in the last decade, both for civil and military use. An autonomous AAR capability is perceived as an advantage to future support and deployment of mid-large scale UAV to meet operational requirements. Despite drawing a lot of attention and research, bow wave effects in an AAR scenario has not received enough attention. Some existing works have discussed and attempted to model the effect of the bow wave from a comparatively large receiver (B-2, C-17) onto the tanker (KC-135) during boom refuelling. However the effects of bow wave from the receiver aircraft onto the drogue in a probe and drogue refuelling system has received very little attention. This paper analyses the effects of the bow wave and results suggest that a solution to the bow wave effect is not only desirable but essential for a successful AAAR refuelling. This paper considers the use of an offset which is used by human pilots to compensate for the drogue movement resulting from the receiver's bow wave. This simple yet effective solution was found to restore the loss in performance in the AAAR simulation which results from the bow wave interaction. This work forms part of the ASTRAEA programme in the UK.