Experimental investigation and analysis of passive aerodynamic wing morphing for extended flight envelopes

Abstract

The aerodynamic performance of unmanned aerial vehicles (UAV) newlinecan be improved by optimizing the surface flow characteristics over a wide newlinerange of angle of attack (AoA) through novel mechanisms. Recently, the newlinebioinspired camber morphing concept has received greater attention because of newlinethe proven ability of nature species towards the retention of aerodynamic newlineperformance under different environmental conditions. In particular, birds like newlineEagles (Accipitriformes) increase their wing camber in the course of flight to newlineachieve maximum climbing altitude with good manoeuvring capability. The newlinebiomimetic designs such as the corrugated bone structure of Eel fish newline(Anguilliformes) helps to achieve the wing camber morphing with optimal newlineaerodynamic load distributions. Hence, the concept of bio-inspired variable newlinecamber morphing (VCM) is proposed herein that minimizes the use of newlineunconventional control surfaces to attain the required performance at different newlinesegments of flight. MQ9 Reaper UAV model is chosen to implement the newlineproposed VCM strategy at the mission flight segments. newlineThe present work is focused to the bioinspired VCM strategy to newlineenhance the flow control behaviour and aerodynamic forces for a specific UAV newlinewing configuration at various AoA. Here, NACA 4412 airfoil is used as a newlinebaseline wing configuration and the camber morphing mechanisms which are newlinederived through Eel fish and Eagle are analysed. The model with Eagle wing newlinemorphing (EWM) mechanism is considered as a primary case of VCM and Eel newlinefish s corrugated structure is taken as a secondary case of VCM model. The newlineVCM strategy from EWM is adopted in a NACA airfoil through computational newlineinvestigation to enhance the lift to drag ratio ( newlineL D/ newline) specifically for military newlineUAV applications. newline