Turbofan engine

• US 8,579,592 B2
• Filed: 04/06/2007
• Issued: 11/12/2013
• Est. Priority Date: 07/04/2006
• Status: Active Grant

• Current Assignee: IHI Corporation
• Original Assignee: IHI Corporation
• Inventors: Kodama, Hidekazu, Goto, Shinya, Mizuta, Ikuhisa, Murooka, Takeshi
• Primary Examiner(s): Lebentritt, Michael
• Application Number:
  US12/307,535
• Publication Number:
  US 20090304518A1
• Time in Patent Office: 2,412 Days
• Field of Search: 416/229.R, 416/239, 416/241
• US Class Current: 416/229.R
• CPC Class Codes: F01D 5/141 Shape, i.e. outer, aerodynamic form F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147
• CPC Class Codes: F04D 29/324 Blades
• CPC Class Codes: F04D 29/384 characterised by form
• CPC Class Codes: F05D 2250/70 Shape
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A hub-side leading edge part of a fan first-stage rotating blade 10 for taking an air thereinto more extends in a forward direction of an engine than a tip-side leading edge part and a mid-span leading edge part. The hub side of the fan first-stage rotating blade 10 is integrally connected as one with the tip side and the mid span while having a longer chord length than those of the tip side and the mid span. A radius at a root of the hub-side leading edge part is set in a boss ratio of 0 to 0.4.

Claims

1. A turbofan engine comprising:

a fan first-stage rotating blade which takes air thereinto and has a hub-side leading edge part extending further in a forward direction of the engine than a tip-side leading edge part and a mid-span leading edge part,

wherein a radius at a root of the hub-side leading edge part is set in a boss ratio of 0 to 0.4, and

wherein the hub-side leading edge part is formed into a convex shape in a span of 0 to 50% and is formed into a linear or a substantially concave shape for the remainder of the span in an outer-radial direction.

2. The turbofan engine according to claim 1, wherein the hub side leading edge part of the fan first-stage rotating blade is integrally connected as one with the tip side leading edge part and the mid span leading edge part while having a chord length longer than the combined chord lengths of the tip side leading edge part and the mid span leading edge part.

3. The turbofan engine according to claim 1, wherein the hub side leading edge part, the tip side leading edge part and the mid span leading edge part are formed toward a downstream side of the engine from the hub side to an outer-diameter side, the hub side leading edge part, the tip side leading edge part and the mid span leading edge part merging smoothly with one another to have a smooth continuously curved fan blade shape, and wherein the hub side leading edge part has a chord length such that the hub side leading edge part merges with the mid span leading edge part at a radial position in a span of 5 to 50% of a trailing edge part.

4. The turbofan engine according to claim 1, wherein the fan first-stage rotating blade is formed into a shape in which two or a plurality of blades are rigidly connected as one with each other by a chemical process.