Slotted aircraft wing
AssigneeThe Boeing Company
InventorsJames D. McLean, David P. Witkowski, Richard L. Campbell
Life of this patent
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Abstract
A swept aircraft wing includes a leading airfoil element and a trailing airfoil element. At least one full-span slot is defined by the wing during at least one transonic condition of the wing. The full-span slot allows a portion of the air flowing along the lower surface of the leading airfoil element to split and flow over the upper surface of the trailing airfoil element so as to achieve a performance improvement in the transonic condition.
Claims38
A swept slotted three-dimensional airfoil having a span and a predetermined three-dimensional shape tailored to improve transonic performance over an un-slotted airfoil, the airfoil comprising:
- at least one leading airfoil element having an upper surface and a lower surface;
- at least one trailing airfoil element defining a full-span transonic cruise slot with the leading airfoil element, the trailing airfoil element having an upper surface and a lower surface, the slot being positioned spanwise along the span at a position where the airfoil experiences Mach critical flow and having a predetermined three-dimensional shape to allow a portion of the air flowing along the lower surface of the leading airfoil element to diverge to flow over the upper surface of the trailing airfoil element and, thereby, to provide the performance improvement, wherein the slot location substantially coincides with a shock location.
A swept aircraft wing comprising a swept slotted three-dimensional airfoil having a span and a predetermined three-dimensional shape tailored to improve transonic performance over an un-slotted airfoil, the airfoil comprising:
- at least one leading airfoil element having an upper surface and a lower surface;
- at least one trailing airfoil element defining a full-span transonic cruise slot with the leading airfoil element, the trailing airfoil element having an upper surface and a lower surface, the slot being positioned spanwise along the span at a position where the airfoil experiences Mach critical flow and having a predetermined three-dimensional shape to allow a portion of the air flowing along the lower surface of the leading airfoil element to diverge to flow over the upper surface of the trailing airfoil element and, thereby, to provide the performance improvement, and
- an actuator structure coupled to the leading and trailing airfoil elements for moving at least one of the leading and trailing airfoil elements relative to the other element,
- wherein the slot includes a plurality of segments longitudinally arranged along the wing, each of the segments being independently adjustable by the actuator structure to allow trimming of the slot differently at different locations along the span.
A method for flying a slotted aircraft wing having a predetermined three-dimensional shape tailored to improve transonic performance over an un-slotted wing, a span, at least one leading airfoil element, and at least one trailing airfoil element defining at least one full-span transonic cruise slot with the leading airfoil element, the slot being positioned along the span at a position where the wing experiences Mach critical flow and such that the slot location substantially coincides with a shock location, the slot having a predetermined three-dimensional shape to allow a portion of the air flowing along a lower surface of the leading airfoil element to diverge to flow over the upper surface of the trailing airfoil element and, thereby, to provide the performance improvement, the method comprising trimming the slot during a transonic condition so as to achieve a performance improvement in the transonic condition.
A method for flying a swept slotted aircraft wing defining at least one full-span transonic cruise slot positioned along the span at a position where the wing experiences Mach critical flow and such that the slot location substantially coincides with a shock location, the slot having a predetermined three-dimensional shape tailored to improve transonic performance over an un-slotted wing, the method comprising using the full-span slot to divert a portion of the air flowing along a lower surface of the wing to flow over an upper surface of the wing during at least one transonic condition of the wing, the diverting at least delaying airflow separation that would occur to add drag at the transonic condition so as to achieve a performance improvement in the transonic condition.
A method for flying a slotted aircraft wing having a predetermined three-dimensional shape tailored to improve transonic performance over an un-slotted wing, a span, a main wing portion, and a flap assembly defining at least one full-span transonic cruise slot with the main wing portion during cruise, the slot being positioned along the span at a position where the wing experiences Mach critical flow and such that the slot location substantially coincides with the shock location, the slot having a predetermined three-dimensional shape to allow a portion of the air flowing along a lower surface of the leading airfoil element to diverge to flow over the upper surface of the trailing airfoil element and, thereby, to provide the performance improvement, the method comprising actuating the flap assembly during cruise to trim the flap assembly so as to achieve a performance improvement during cruise.
Dependencies are inferred from the claim text.