초록 ▼

The pressure drag on the skin of an aircraft is reduced by rigidly securing boundary layer influencing members to the skin of the aircraft, including the wings, the elevantor and fin/rudder assemblies, and the body near the tail end. These members may be vortex generators and boundary layer diverter

The pressure drag on the skin of an aircraft is reduced by rigidly securing boundary layer influencing members to the skin of the aircraft, including the wings, the elevantor and fin/rudder assemblies, and the body near the tail end. These members may be vortex generators and boundary layer diverters and are always located in the attached flow. In addition, if the members are placed upstream of any air intakes, especially flush air intakes, the air intake efficiency is also improved. The influencing members have an effective height above the surface corresponding, at the most, to the displacement thickness portion of the boundary layer.

대표청구항 ▼

An apparatus for influencing a boundary layer o nan aircraft surface including wing surfaces, elevator surfaces, fin/rudder surfaces, and body surfaces, comprising boundary layer influencing means rigidly secured to said wing surfaces approximately along the entire wing span in a fully attached boun

An apparatus for influencing a boundary layer o nan aircraft surface including wing surfaces, elevator surfaces, fin/rudder surfaces, and body surfaces, comprising boundary layer influencing means rigidly secured to said wing surfaces approximately along the entire wing span in a fully attached boundary layer flow downstream of the largest wing thickness as viewed in the air flow direction but upstream of any boundary layer separation point, said boundary layer influencing means being also secured to said elevator surfaces in a fully attached boundary layer flow downstream of the largest elevator thickness but upstream of any boundary layer separation point, to said fin/rudder surfaces in a fully attached boundary layer flow downstream of the largest fin/rudder thickness but upstream of any boundary layer separation point, and to said body surfaces in a fully attached boundary layer flow approximately around an entire body circumference of the aircraft tail end but upstream of any boundary layer separation point, said boundary layer influencing means having an effective height shorter than a respective displacement thickness of the corresponding fully attached boundary layer on the respective surface whereby the pressure drag component of the total drag effective on the aircraft is reduced. A flush air inlet construction for an aircraft having a body with a skin, comprising flush air inlet means (15) having a given width (W) for supplying air into the aircraft, a hinged flap (14) for opening and closing said flush air inlet means, and a boundary layer diverter (13, 13″) arranged directly upstream of a hinged end of said flap (14) of said flush air inlet means, said boundary layer diverter (13, 13″) having a diverter width corresponding at least to said given width (W) of said flush air inlet means for diverting the boundary layer substantially completely away from said flush air inlet means for effectively reducing total pressure drag and for improving air intake efficiency.