초록 ▼

An air inlet and scoop for aircraft auxiliary power units to provide satisfactory performance thereof under all operational conditions, including full capability for in-flight starting at high altitudes, whereby operational difficulties caused by thick boundary layers and adverse pressure gradients

An air inlet and scoop for aircraft auxiliary power units to provide satisfactory performance thereof under all operational conditions, including full capability for in-flight starting at high altitudes, whereby operational difficulties caused by thick boundary layers and adverse pressure gradients between the inlet and the tail cone in the vicinity of the inlet are overcome. The inlet opening is contoured along its outer edges to conform to the aircraft fuselage and has a ramp trailing inwardly into the opening, starting at the fuselage and forming the bottom surface of the inlet. The inlet has generally parallel side walls trailing inwardly, the inlet side walls extending inwardly from the fuselage edges along the inlet opening. A scoop is hinged adjacent the fuselage at one end of the inlet opening, the aircraft having means therein to operate the scoop so as to open and close the inlet opening. The scoop has a closing wall surface with respect to the inlet opening, which when in the closed position is contoured to conform with the fuselage, the closing wall surface being continuous in the open and closed positions and generally limited to the extent of the inlet opening. The method of overcoming the problems of thickness of boundary layer and adverse pressure gradient between the inlet and tail cone in the vicinity of the inlet.

대표청구항 ▼

For use on an aircraft, an air inlet and scoop for an in-flight auxiliary power unit, the scoop being adapted to open and start operation at altitude and on the ground, comprising: an inlet opening contoured along its outer edges to conform to the aircraft fuselage, a ramp trailing inwardly into the

For use on an aircraft, an air inlet and scoop for an in-flight auxiliary power unit, the scoop being adapted to open and start operation at altitude and on the ground, comprising: an inlet opening contoured along its outer edges to conform to the aircraft fuselage, a ramp trailing inwardly into the opening starting from the fuselage and forming the bottom surface of the inlet; the inlet opening having generally parallel side walls trailing inwardly along opposite edges of the ramp; the side walls extending inwardly from the fuselage edges along the inlet opening; a scoop hingedly engaged to said aircraft adjacent said fuselage and adjacent one end of said inlet opening; and means in said aircraft to operate said scoop from positions in which said scoop opens and closes said inlet opening; said scoop having a closing wall with respect to said inlet opening, said closing wall closing said opening in the closed position and being contoured to conform with the fuselage surface in the closed position; said closing wall being continuous in the open and closed positions and generally limited to the extent of said inlet opening; said scoop being externally of said aircraft in the closed position; said scoop having a cross section complementary to said inlet to fit therein in the open position; said scoop having a passage therethrough to permit inlet air to move therethrough from outside the fuselage into the inlet.