Piston Bowl With Spray Jet Targets

A piston for a direct injection engine, the piston comprising a bowl at an upper end, the bowl forming a portion of a combustion chamber, wherein the piston has a top face defining a plane and the bowl includes an inner surface that defines a volume configured to receive a fuel-air mixture, the inner surface of the bowl including:

• at least one surface feature recessed into or protruding from said inner surface as a target for fuel spray, the at least one surface feature including a central portion angled between 20° and 80° from said plane of said top face and having a cross-section that protrudes from or is recessed into said inner surface by 0.5 mm to 12.7 mm, wherein edges formed as a recess or projection are disposed adjacent the top and bottom and along the central portion of the shaped feature.

A method of operating an internal combustion engine having at least one cylinder and a piston slidably disposed within the at least one cylinder, the method comprising:

• moving the piston toward a top dead center position during a compression stroke;
• spraying a fuel and air mixture into a piston bowl recessed in said piston, wherein the piston has a top face defining a plane and the bowl includes an inner surface that defines a volume configured to receive said fuel-air mixture, the inner surface of the bowl including at least one surface feature recessed into or protruding from said inner surface as a target for fuel spray, the at least one surface feature angled between 20° and 80° from said plane of said top face and having a cross-section that protrudes from or is recessed into said inner surface by 0.5 mm to 12.7 mm;
• wherein said at least one surface feature redirects said fuel-air mixture upon impact with said target to provide additional fuel-air mixing.