Gas turbine engine two degree of freedom variable bleed valve for ice extraction

An aircraft gas turbine engine comprising:

• in downstream serial flow communication a fan, a booster, and a high pressure compressor circumscribed about an engine centerline;
• a bypass duct spaced radially outwardly from the booster;
• an annular fan frame supporting a fan casing surrounding the fan and the bypass duct;
• the fan frame including an annular outer frame casing, a fan hub frame, and a plurality of circumferentially spaced apart duct struts extending therebetween;
• a transition duct located at a radially inner end of the fan hub frame and axially disposed between and in fluid communication with the booster and the high pressure compressor;
• bleed exhaust ducts extending from the fan hub frame to the bypass duct;
• at least one variable bleed valve including a single variable bleed valve door disposed in a bleed inlet in the transition duct;
• the single variable bleed valve door pivotable or rotatable about two or more separate pivot points;
• the variable bleed valve operable to open and close an aft bleed slot extending generally radially outwardly from the transition duct and extending between an aft lip located at a downstream or aft end of the single variable bleed valve door and the transition duct;
• and
• the variable bleed valve operable to open and close a forward bleed slot in fluid communication with at least one of the bleed exhaust ducts and extending generally radially inwardly into the transition duct and extending between a forward lip located at an upstream or forward end of the single variable bleed valve door and the transition duct;
• and
• further comprising the variable bleed valve operable to transition the single variable bleed valve door between a first position with the aft bleed slot being open and the forward bleed slot being closed to a second position with the aft bleed slot being closed and the forward bleed slot being open without fully closing the single variable bleed valve door.

An aircraft gas turbine engine comprising:

• in downstream serial flow communication a fan, a low pressure compressor, and a high pressure compressor circumscribed about an engine centerline;
• a bypass duct spaced radially outwardly from a booster;
• an annular fan frame supporting a fan casing surrounding the fan and the bypass duct;
• the fan frame including an annular outer frame casing, a fan hub frame, and a plurality of circumferentially spaced apart duct struts extending therebetween;
• a transition duct located at a radially inner end of the fan hub frame and axially disposed between and in fluid communication with the low pressure compressor and the high pressure compressor;
• bleed exhaust ducts extending from the fan hub frame to the bypass duct;
• at least one variable bleed valve including a single variable bleed valve door disposed in a bleed inlet in the transition duct;
• the single variable bleed valve door pivotable or rotatable about two or more separate pivot points;
• the variable bleed valve operable to open and close an aft bleed slot extending generally radially outwardly from the transition duct and extending between an aft lip located at a downstream or aft end of the single variable bleed valve door and the transition duct;
• and
• the variable bleed valve operable to open and close a forward bleed slot in fluid communication with at least one of the bleed exhaust ducts and extending generally radially inwardly into the transition duct and extending between a forward lip located at an upstream or forward end of the single variable bleed valve door and the transition duct;
• and
• further comprising the variable bleed valve operable to transition the single variable bleed valve door between a first position with the aft bleed slot being open and the forward bleed slot being closed to a second position with the aft bleed slot being closed and the forward bleed slot being open without fully closing the single variable bleed valve door.

A method of operating a variable bleed valve including a single variable bleed valve door disposed in a bleed inlet in a transition duct, the method comprising:

• pivoting or rotating the single variable bleed valve door about an axis at and translating the axis between two or more separate pivot points,
• opening and closing an aft bleed slot extending generally radially outwardly from the transition duct and extending between an aft lip located at a downstream or aft end of the single variable bleed valve door and the transition duct by translating the axis between two or more separate pivot points, and
• opening and closing a forward bleed slot extending generally radially inwardly into the transition duct and extending between a forward lip located at an upstream or forward end of the single variable bleed valve door and the transition duct by rotating the single variable bleed valve door about the axis, and
• further comprising transitioning the single variable bleed valve door between a first position with the aft bleed slot being open and the forward bleed slot being closed to a second position with the aft bleed slot being closed and the forward bleed slot being open without fully closing the single variable bleed valve door during the transitioning.