| 摘要 |
The present invention provides a method of designing a manufacturing geometry for a tip portion (28) of a rotary blade (25) for a gas turbine engine. The method comprises first devising a theoretical hot running geometry of the tip portion at a specified design condition. Next, the theoretical operational forces acting on the theoretical hot running geometry at the specified design condition are calculated e.g. using CFD software. Then, the manufacturing geometry is determined (e.g. using FEA analysis) using the calculated theoretical operational forces. The specified design condition is selected as an engine running condition at which the radial growth and twist of the rotary blade is maximum. The manufactured tip portion of the rotary blade has a convex profile along the camber line in a cold condition, wherein the spacing between the casing (24) and the tip portion (28) is constant along the camber line at a hot running condition. |
