Inclination of forward and aft groove walls of casing treatment for gas turbine engine

A compressor for use in a gas turbine engine, the gas turbine engine comprising:

• an airfoil configured to rotate about an engine central longitudinal axis of the gas turbine engine, wherein the airfoil further comprises a blade tip;
• a casing, the casing including a radially inward surface;
• and
• a groove located within the casing opposite the airfoil, the groove is recessed in a radially outward direction from the radially inward surface of the casing, wherein the groove is defined by a forward groove wall, an aft groove wall opposite the forward groove wall, and a base groove interposed between the forward groove wall and the aft groove wall,
• wherein the aft groove wall is operably shaped to reduce airflow separation proximate an intersection of the radially inward surface of the casing and the aft groove wall,
• wherein the aft groove wall is curved in shape,
• wherein the groove is wider than the blade tip as measured forward to aft, and
• wherein the aft groove wall is convex in shape or the aft groove wall includes a convex portion and a concave portion.

A fan case for use in a gas turbine engine, the fan case being configured to enclose an airfoil rotating about an engine central longitudinal axis of a gas turbine engine, the fan case comprising:

• a groove located within the fan case opposite the airfoil, the groove is recessed in a radially outward direction from a radially inward surface of the fan case, wherein the groove is defined by a forward groove wall, an aft groove wall opposite the forward groove wall, and a base groove interposed between the forward groove wall and the aft groove wall, and
• wherein the forward groove wall is operably shaped to generate an aft directed jet,
• wherein the groove is wider than a blade tip of the airfoil as measured forward to aft,
• wherein the aft groove wall is operably shaped to reduce airflow separation proximate an intersection of the radially inward surface of the fan case and the aft groove wall,
• wherein the aft groove wall is curved in shape, and
• wherein the aft groove wall is convex in shape or the aft groove wall includes a convex portion and a concave portion.