Characterisation of a highly staggered spanwise cambered biplane

Abstract

An investigation is presented to elucidate the performance of a staggered, spanwise cambered biplane. The spanwise camber yielded wings forming a '∧' or '∨' when viewed streamwise. The configuration is examined in terms of its aerodynamic and stability characteristics. The feasibility of negating the requirement for a conventional empennage is explored. Geometric variation encompassed front and back wing anhedral/dihedral angles yielding 49 combinations. Evaluation of the geometry was accomplished using both wind tunnel testing and numerical simulation. The results indicated that front wing dihedral in conjunction with aft wing anhedral was most beneficial, such that the benefit of wake spacing was maximised. Aerodynamic benefit was indicated compared to a conventional empennage geometry. The greatest disparity in behaviour of the fore and aft wing anhedral/dihedral distribution was in the high lift regime, where the nature of the stall varied. Simulations to establish the viability of the geometry in terms of controllability were also conducted and indicated that the configuration is viable.

Investigation on shock-induced separation loss mitigation method considering radial equilibrium in a transonic compressor rotor

“…In a transonic compressor rotor, the spanwise transport is also a key flow characteristic that must be taken into account [19,20]. Because of the difference in tangential velocity components between the main flow and boundary layer, the centripetal force required for the circumferential motion of the low-momentum fluids in the boundary layer is greater than that generated by the radial adverse pressure gradient [21].…”