Patent ID: 6416289
Filing Date: 2002-07-09
Classification: B64C,F01D,F05D,Y02T,Y10S

Abstract:
An axial flow turbine having downstream of a first row of aerofoils of the turbine, at least one further row of aerofoils each of which aerofoils being provided with a suction surface, a leading edge, and a trailing edge, adjacent aerofoils in said further row cooperating to define a geometric throat, said aerofoil suction surface being smooth except for a surface region having an increased roughness provided on said suction surface of each aerofoil, said region having an upstream boundary substantially between the location of the geometric throat on the suction surface and a location 75% of the suction surface perimeter from the leading edge and having an extent of at least 3% of said perimeter wherein the roughness (Ra) of said region, normalized to the aerofoil chord (Ra/C) is between 3Ã—10âˆ’5 to 1Ã—10âˆ’3.