초록 ▼

An airfoil for transonic speeds includes a porous top surface extending from a location about 50 to 60% of the chord length from a leading edge of the airfoil to a location about 80 to 90% of the chord length from the leading edge. A cavity is defined under the porous surface in the airfoil which ha

An airfoil for transonic speeds includes a porous top surface extending from a location about 50 to 60% of the chord length from a leading edge of the airfoil to a location about 80 to 90% of the chord length from the leading edge. A cavity is defined under the porous surface in the airfoil which has a depth of from 0.05 to 0.2% of the chord length. The porosity of the porous surface is chosen to be from 1 to 3% of the total airfoil surface and may be variable. The presence of the porous surface and cavity decrease airfoil drag at transonic speeds by providing a pathway between a high pressure area downstream of a shock wave formed on the airfoil at transonic speeds to a low pressure area within a bubble on the airfoil upstream of the shock wave.

대표청구항 ▼

An airfoil for transonic speeds having a leading edge and comprising a porous top surface area extending from a location at about 50 to 60% of a chord length from the leading edge, to a location at about 80 to 90% of the chord length from the leading edge, and passive means defining a cavity under s

An airfoil for transonic speeds having a leading edge and comprising a porous top surface area extending from a location at about 50 to 60% of a chord length from the leading edge, to a location at about 80 to 90% of the chord length from the leading edge, and passive means defining a cavity under said porous top surface area and in the airfoil having a depth of from 0.05 to 0.2% the chord length. A passive method of reducing drag of an airfoil at transonic speeds comprising providing a porous surface area on the airfoil extending as close as 50% of a chord length from a leading edge of the airfoil to as far as 90% of the chord length from the leading edge of the airfoil, and defining a cavity below the porous surface area for passing air from a high pressure area downstream of a pressure wave established on the airfoil during transonic speeds, to a low pressure area upstream of the shock wave and not elsewhere.