Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A jet engine which includes: a fan with a plurality of stages of rotor blades; a compressor compressing air sent from the fan; a combustor generating combustion gas by using compressed air generated by the compressor; a turbine generating a driving force from the combustion gas; a nozzle discharging the combustion gas; a variable guide vane disposed upstream of the rotor blades of a second and later stage of the rotor blades of the fan and adjusts an inlet angle of air flow against the second and later stage of the rotor blades; a fluid resistance adjusting device adjusting a fluid resistance at the nozzle; and a controller which controlling the variable guide vane such that the inlet angle at the time of cruise flight is smaller than the inlet angle at the time of acceleration.

Abstract: 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.

Abstract: 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.

Abstract: To provide a blade of a fan or compressor that is reduced in loss by enlarging a laminar flow region over a blade surface. A blade according to the present disclosure 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.

Abstract: A rotor blade main body includes multiple first composite sheet groups and multiple second composite sheet groups which are provided in a blade thickness direction. Each first composite sheet group includes multiple composite sheets which are stacked one on another from a blade thickness center side toward a dorsal surface. Each second composite sheet group includes multiple composite sheets which are stacked one on another from the blade thickness center side toward a ventral surface. A composite direction of orientation directions of fibers in the multiple composite sheets in each of the sheet groups inclines by 20 degrees to 45 degrees from a span direction.

Abstract: A coupling support member including a pair of divided pieces is placed between an end portion of a guide vane and an attachment flange, and the pair of divided pieces is joined to the vane end portion from both sides in the vane thickness direction. A linear protrusion is formed on one of joint surfaces of the vane end portion. A groove engaged with the linear protrusion is formed in one of respective joint surfaces of the pair of divided pieces. The vane end portion is fastened between the pair of divided pieces. It is possible to obtain a high structural strength while contributing to a reduction in weight of a jet engine.

Abstract: A jet engine which includes: a fan provided with a plurality of stages of rotor blades; a compressor which compresses air which is sent from the fan; a combustor which generates combustion gas by using compressed air generated by the compressor; a turbine which generates a driving force from the combustion gas; and a nozzle which discharges the combustion gas, the jet engine further includes: a variable guide vane which is disposed upstream of the rotor blades of a second and later stage of the rotor blades of the fan and which adjusts an inlet angle of air flow against the second and later stage of the rotor blades; a fluid resistance adjusting device which adjusts a fluid resistance at the nozzle; and a controller which controls the variable guide vane such that the inlet angle at the time of cruise flight is smaller than the inlet angle at the time of acceleration and controls the fluid resistance adjusting device such that increase in the fluid resistance, due to an increase in a volume flow at an outlet

Abstract: An axial flow device includes: at least one stage of a compressor including a rotor blade row and a stator vane row; a casing housing the compressor; and an operating range expansion unit having a suction port that opens into a region corresponding to the rotor blade row in an inner surface of the casing, a blow-out port that opens anterior to the rotor blade row in the inner surface of the casing, and a hollow section that is formed inside the casing and communicates the suction port with the blow-out port. A flow path in the blow-out port is inclined reversely to a rotation direction of the rotor blade row relative to the radially inward side.

Abstract: A fan rotor blade includes a blade body constructed of a composite material, a blade root constructed of the composite material, and a sheath attached to a leading edge of the blade body. The sheath includes a sheath main body and a pair of joint flanges, and is segmented into a sheath base segment and a sheath top segment. The sheath top segment has a longer length than a length of the sheath base segment along a span direction. A sheath length of the sheath main body at an assumed impact position with an obstacle is not shorter than 10% chord and not longer than 60% chord. A sheath length of the sheath along an end edge of the fan rotor blade is not shorter than 40% chord. The fan rotor blade possesses sufficient impact resistance and can be simplified and light-weighted.

Abstract: A fan rotor blade has a rotor blade leading edge. On a hub side of the rotor blade leading edge, a vertical hub section is formed. From a top end of the vertical hub section to a mid-span side of the rotor blade leading edge, a backward tilt mid-span section is formed. From a top end of the backward tilt mid-span section to a tip end of the rotor blade leading edge, a forward tilt tip section is formed. From a hub end of the rotor blade leading edge to a base end of the vertical hub section, a backward tilt hub section is formed. The backward tilt hub section is backwardly tilted so that a top end thereof is positioned behind a base end thereof.

Abstract: A coupling support member including a pair of divided pieces is placed in a coupling part between a vane proximal end portion of a guide vane and an attachment flange, and the pair of divided pieces are joined to the vane proximal end portion from both the sides in the vane thickness direction. A linear protrusion is formed on one of joint surfaces of the vane proximal end portion to the pair of divided pieces. A groove engaged with the linear protrusion formed in the vane proximal end portion is formed on one of respective joint surfaces of the pair of divided pieces of the coupling support member. The vane proximal end portion is held between the pair of divided pieces of the coupling support member, by the fastening force that is applied to the pair of divided pieces of the coupling support member from both the sides in the vane thickness direction. It is possible to obtain a high structural strength while contributing to a reduction in weight of a jet engine.

Abstract: A rotor blade main body includes multiple first composite sheet groups and multiple second composite sheet groups which are provided in a blade thickness direction. Each first composite sheet group includes multiple composite sheets which are stacked one on another from a blade thickness center side toward a dorsal surface. Each second composite sheet group includes multiple composite sheets which are stacked one on another from the blade thickness center side toward a ventral surface. A composite direction of orientation directions of fibers in the multiple composite sheets in each of the sheet groups inclines by 20 degrees to 45 degrees from a span direction.

Abstract: A fan rotor blade has a rotor blade leading edge. On a hub side of the rotor blade leading edge, a vertical hub section is formed. From a top end of the vertical hub section to a mid-span side of the rotor blade leading edge, a backward tilt mid-span section is formed. From a top end of the backward tilt mid-span section to a tip end of the rotor blade leading edge, a forward tilt tip section is formed. From a hub end of the rotor blade leading edge to a base end of the vertical hub section, a backward tilt hub section is formed. The backward tilt hub section is backwardly tilted so that a top end thereof is positioned behind a base end thereof.

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.

Abstract: A compressor stator blade 10 includes a seal mechanism 12 configured to hermetically seal a part between a radial inner end on the upstream side and an outer surface of a rotary body, and a remainder part on the downstream side of the seal mechanism includes a hub clearance 14 between the outer surface of the rotary body and itself. Additionally, a compressor rotor blade 20 includes a seal mechanism 22 configured to hermetically seal a part between a radial outer end on the upstream side and an inner surface of a stationary body, and a remainder part on the downstream side of the seal mechanism includes a tip clearance 24 between the inner surface of the stationary body and itself.

Abstract: A fan rotor blade includes a blade body constructed of a composite material, a blade root constructed of the composite material, and a sheath attached to a leading edge of the blade body. The sheath includes a sheath main body and a pair of joint flanges, and is segmented into a sheath base segment and a sheath top segment. The sheath top segment has a longer length than a length of the sheath base segment along a span direction. A sheath length of the sheath main body at an assumed impact position with an obstacle is not shorter than 10% chord and not longer than 60% chord. A sheath length of the sheath along an end edge of the fan rotor blade is not shorter than 40% chord. The fan rotor blade possesses sufficient impact resistance and can be simplified and light-weighted.

Abstract: In a blade row of an axial flow type compressor in which a rotor blade row and a stator blade row are alternately arranged in an axial direction, the stator blade row 10 is formed by plural main stator blades 12 and plural sub-stator blades 14. Each main stator blade 12 is formed by a basic blade portion 12a which has the same shape as that of each sub-stator blade and a forward blade portion 12b which extends to the upstream side of the basic blade portion. The basic blade portion 12a are located at the same position in an axial direction. The forward blade portion 12b forms a forward stator blade row which has a circumferential interval larger than that of the basic stator blade row in the vicinity of at least a radial inner end.