Ihi Corporation

Tomonori Enoki

Takeshi Murooka

Ryuichi Okada

Ryosuke Hayashi

Hiroyuki Yagi

Takaomi Inada

Dai Kato

Rintarou Kajiwara

To provide a method of designing a blade of an axial flow fluid machine that has a blade surface whose radius of curvature is continuous at a leading edge thereof and has a high aerodynamic performance. The method includes a step of determining a pressure surface curve and a suction surface curve as curves capable of first to third order differentiations at respective connection points to a leading edge curve, that is, a pressure surface connection point and a suction surface connection point, and a step of forming the leading edge curve as a fifth order Bezier curve that is defined by a first control point, a second control point, a third control point, a fourth control point, a fifth control point and a sixth control point. The first control point is the suction surface connection point. The sixth control point is the pressure surface connection point. Provided that an intersection of a tangent to the pressure surface curve at the pressure surface connection point and a tangent to the suction surface curve at the suction surface connection point is referred to as a point ahead of the blade, the second and fifth control points are points that internally divide line segments connecting the point ahead of the blade to the suction surface connection point and the pressure surface connection point, respectively. The third and fourth control points are points having coordinates that are determined as solutions of simultaneous equations obtained by applying continuity conditions for first to third differential coefficients at the first and sixth control points to a fifth order Bezier function.

Method of designing blade of axial flow fluid machine and blade

To provide a stator vane of a fan or compressor that is reduced in loss by enlarging a laminar flow area over a blade surface. With the stator vane, provided that an angle formed by a tangent to the blade surface at a point and the axial direction of the turbofan engine, that is, a parameter that is a blade surface angle normalized is referred to as a normalized blade surface angle, an upper limit is set for the change rate in the chord direction of the normalized blade surface angle on the pressure surface, and an upper limit is set for the normalized blade surface angle at a predetermined location in the chord direction on the suction surface.

Stator vane of fan or compressor

A blade of a fan or compressor that reduces loss by enlarging a laminar flow region over a blade surface is provided. The blade is divided into a subsonic region where the relative Mach number of the inlet air flow during rated operation of a turbofan engine is lower than 0.8 and a transonic region where the relative Mach number is equal to or higher than 0.8. A blade surface angle change rate is based on an angle formed by a tangent to the blade surface and the axis of the engine, the leading edge blade surface angle, and the trailing edge blade surface angle at. In each of the subsonic region and the transonic region, values of the blade surface angle change rate on the pressure and suction surfaces are defined at predetermined axial locations along the chord on the pressure and suction surfaces.

Blade of fan or compressor

A stator-vane structure that can suppress pressure loss caused by a gap or a level difference between liners, while forming an air channel with stator vanes made of a composite material and the liners in a turbofan engine, and the turbofan engine employing this stator-vane structure are provided. Inner liners are made to butt against each other so as to clamp therebetween a vane base section of a fan exit guide vane (stator vane) made of a composite material, outer liners are made to butt against each other so as to clamp therebetween a vane tip section of the fan exit guide vane, respectively, and division lines that are formed between these liners on a leading-edge side are made to be along a streamline direction.

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Koto-ku, Japan

Tomonori Enoki