Turbomachine with serrated-profile flow-splitter nose

Patent metadata

Field	Value
Publication number	US-2020408101-A1
Application number	US-201916970526-A
Country	US
Kind code	A1
Filing date	Feb 15, 2019
Priority date	Feb 16, 2018
Publication date	Dec 31, 2020
Grant date	—

Abstract

A front fan turbomachine comprising an annular separating wall ( 160 ) having a slat ( 16 ) for separating an air flow between a primary flow and a secondary flow, the slat having a leading edge; IGV blades for guiding the primary flow and OGV blades for guiding the secondary flow.
The leading edge of the slat ( 16 ) has a serrated profile ( 28 ) having a succession of teeth and depressions.

First claim

1 .- 7 . (canceled)

8 . Turbomachine having a front fan ( 14 ) in which an airflow can circulate from upstream to downstream, the turbomachine having a general axis (X) about which the front fan can rotate, the front fan generating a wake downstream when it rotates, the turbomachine comprising:
an annular dividing wall ( 160 ) having a slat ( 16 ), for dividing the airflow downstream of the fan ( 14 ) into a primary flow and a secondary flow, the slat ( 16 ) having a leading edge, first guide vanes (IGV 24 ) for guiding the primary flow (Fp), second guide vanes (OGV 26 ) for guiding the secondary flow (Fs),
characterised in that the leading edge of the slat ( 16 ) of the annular dividing wall ( 160 ) has a serrated profile ( 28 ) having a succession of teeth ( 30 ) and undulating depressions ( 32 ):
that define:
along a direction (L) of elongation of the leading edge, a repeating elementary geometry, two identical undulations of two successive elementary geometries ( 34 , 36 ) along said direction (L) having between them, along said direction, a distance (λ),
and a maximum amplitude (h), perpendicular to said direction (L) along which the leading edge has a length, and

which meet at least one of the following criteria a), b), c):
a) the maximum amplitude (h) is dimensioned according to the relation: l 11 (1) /h<1 to within 40%, in the formula:

l
ij

(
k
)

=

∫
0
∞



〈

u
i
′



(

x
+

re
k

)



u
j
′



(
x
)

〉

〈

u
i
′



(
x
)



u
j
′



(
x
)

〉


dr

with:
u′i which is the airflow ( 38 ) velocity in direction i, between the front fan ( 14 ) and the first guide vanes ( 24 , IGV),
r which is the distance between two points in the wake of the front fan ( 14 ) in a k-direction,
l 11 (1) which is the integral scale of the airflow ( 38 ) generated by the front fan ( 14 ), in the direction of a chord ( 40 ) of the profile, or parallel to the general axis (X) of the turbomachine,

b) said distance (λ) respects the following relationship:
e<λ≤d−e where d/λ≠ 1, 2, 3, . . . , having:

e which is the width of the airflow ( 28 ) generated by the front fan ( 14 ) in the wake of one of said blades ( 140 ) of the front fan ( 14 ), said width being calculated at a point where half of the maximum turbulent kinetic energy, K_max, generated in said wake is found; e being estimable from the criterion e =l 22 (2) /0,21, to within 40%, and
d which is the spacing between two circumferentially consecutive blades ( 140 ) of the front fan ( 14 ),

c) the number of teeth ( 30 ), depressions ( 32 ), or repetition periods of the elemental geometry along the length of the leading edge is equal, within 40%, to the number of the first guide vanes ( 24 , IGV).

9 . Turbomachine according to claim 8 , wherein:
the first guide vanes ( 24 , IGV) have an angular position (β) with respect to the general axis (X), and around said general axis (X), at least some of said depressions ( 32 ) of the serrated profile ( 28 ) are angularly offset with respect to the angular position (β) of the first guide vanes ( 24 , IGV), so that said at least some of the depressions ( 32 ) are angularly interposed between two of said first guide vanes ( 24 , IGV) circumferentially successive.

10 . Turbomachine according to claim 8 , wherein:
the front fan ( 14 ) is adapted to rotate in a predetermined direction (Y) about said general axis (X) such that the airflow ( 38 ) downstream of the fan is generally obliquely oriented with respect to said general axis (X) at an angle (α), and the teeth ( 30 ) are inclined circumferentially around said general axis (X) towards the generally oblique orientation (α) of the airflow downstream of the front fan ( 14 ), to face it generally.

11 . Turbomachine according to claim 9 , wherein:
the front fan ( 14 ) is adapted to rotate in a predetermined direction (Y) about said general axis (X) such that the airflow ( 38 ) downstream of the fan is generally obliquely oriented with respect to said general axis (X) at an angle (α), and the teeth ( 30 ) are inclined circumferentially around said general axis (X) towards the generally oblique orientation (α) of the airflow downstream of the front fan ( 14 ), to face it generally.

12 . Turbomachine according to claim 8 , wherein:
the first guide vanes ( 24 , IGV) individually have a camber line ( 240 ) and a leading edge ( 25 ), and the teeth ( 30 ) are, circumferentially around said general axis (X) and individually, oriented generally in the direction of a tangent ( 42 ) to the camber line ( 240 ) of said first guide vanes ( 24 , IGV) passing by the leading edge ( 25 ), said tangent forming a (β) non-zero angle with respect to the direction of the general axis (X) of the turbomachine.

13 . Turbomachine according to claim 9 , wherein:
the first guide vanes ( 24 , IGV) individually have a camber line ( 240 ) and a leading edge ( 25 ), and the teeth ( 30 ) are, circumferentially around said general axis (X) and individually, oriented generally in the direction of a tangent ( 42 ) to the camber line ( 240 ) of said first guide vanes ( 24 , IGV) passing by the leading edge ( 25 ), said tangent forming a (β) non-zero angle with respect to the direction of the gener

Assignees

• Safran Aircraft Engines

Inventors

• Gea Aguilera Fernando
• Fiack Matthieu
• Gruber Mathieu Simon Paul

Classifications

• F05D2250/184

  sinusoidal · CPC title

• F02C7/045

  having provisions for noise suppression · CPC title

• B64C7/02

  Nacelles · CPC title

• F05D2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title