BE1026810B1 - DYNAMIC CONTOURING - Google Patents

Abstract

The invention relates to an assembly or a low-pressure compressor for a turbojet engine. A ferrule (32) supporting vanes (26) has a generally axisymmetric surface (34) and means (42, 44) making it possible to dynamically provide the ferrule (32) with a protuberance - also called contouring. The protrusion may take the form of a plurality of needles (50) projecting from the surface (34) by actuators (42). The actuators (42) can also directly deform the ferrule (32) to create a bump. Finally the ferrule (32) can include a reduction in thickness resulting in an inhomogeneous expansion causing a bump to appear. The invention also relates to a method for controlling a contouring during operation of the turbojet engine, the contouring being removable as a function for example of the detection of a detachment of the air flow.

Description

Description

Doinetecnie

The invention relates to a compressor inter-blade surface. The invention also relates to an axial turbomachine, in particular an aircraft turbojet or an aircraft turboprop. Finally, the invention relates to a control process.

Prior art

The document ! # $ %% &&& '% discloses a turbojet engine comprising a turbomachine compressor. nter two consecutive blades of the compressor is a non-axis (metric) surface, also designated by the English term * + ontouring #, -, with bumps and hollows. + protuberances arranged in the inter-blade air passage make it possible to improve the efficiency of the turbojet engine. This phenomenon can only be explained by better control of the flow in the passage, through precise management of the secondary flows such as flow convergences or by minimizing the risks of separation of the flow. / however, depending on the operating point 0 motor speed, pressure, temperature 1, the behavior of the flow can vary greatly and the benefits of contouring can diminish or even become harmful. , in the state of the art, this is not taken into account and during the design, a compromise is therefore made to obtain a mo result (in all the operating points. 2l therefore exists a significant potential to improve this aspect.

esu! e # in $ ention

3 technical problem

The object of the invention is to solve at least one of the problems posed by the prior art. 3read more specifically, the invention aims to optimize the flow rate and the compression rate, at any point of operation of the turbojet engine. The invention also aims to provide a resistant and reliable solution.

2018/5834

BE2018 / 5834

5 technical solution

The subject of the invention is an assembly for a turbomachine, comprising a united ferrule a uce i (ti) ue e uie lu lu lenele tnt remar) uable en ce) u'il comprise a plurality of needles and an actuator for moving the needles between at least had positions have a position in the) which the needles are projecting and the surface e uiae ais (mtri) ue 'insi, there is at least one projecting position and at least one other position which can be a retracted position in the) that the needles are not protruding from the ferrule, or a position that is less protruding The actuator may in particular be provided for positioning the needles in several iscr.tes positions or even an ininit e positions between had narrow positions

The invention also has for ob4et an assembly for a turbomachine comprising a ferrule provided with a wall having a surface area (metric) with an air, the assembly so much remarkable in that it includes an actuator to locally adorn the wall so the area appears a protruding bump on the surface ais (mtri) ue e uiae

The invention also has for ob4et an assembly for a turbomachine having the ferrule comprising less thick portions, so when the heat is generated by the turbomachine, the protuberances appear on the 8 th least thicker

According to the terms before the invention, the set includes at least one of the following characteristics, taken in isolation or in any possible combination 9

The plurality of needles is made up of needles parallel to each other and: or holding perpenicularly the eye and the ferrule

The plurality of needles includes the needles distributed circumferentially and: or radially n protruding position, at least if the needles overhang the surface and that have a prominent height 3 particularly, the points of the plurality of needles aim to form an elongated profile. bump

2018/5834

BE2018 / 5834

- The tip of the needles is profiled, 'insi, the air flow is not abruptly interrupted by the tip of the needles.

- The set of needles can be irular, oal, or profiled in the form of a dawn, that is to say on a lower and upper surface,

- The needles are provided with mo (ensffage, 3ar example, the needles can integrate an electric resistan), be rous and appeared by a fluid of bunch, be reuse and provided with an orifies their point to reet a fluid of auffe in the air flow, The auffage mo can be ordered independently of the movement of the needle, and in particular depending on the need for auffage or unclogging of the compressor,

- The needles are made of a flexible material, The needles can be provided to bend slightly, 4us) u 'e) ue their points are offset ers aal under the aation of air, about one third of their author's color, depending on the position of the needles in the flow of the turbo-jet, the needles can be made of aluminum alloy or titanium and have a size small enough to allow them to swell under the air aation ,

- The maximum author of the bump or the author projecting from the needles is omitted between%; and <; from the radial author of dawn,

- The author of the hump and: or the protrusion of the needles measures at least $ 9, $ <mm, or $,% mm, or $, <mm, ou = mm> and: or at most 9 = m, or % m, or <mm, or # mm,

- The needles are spaced from each other axially and: or ironferentially by a distance between $, <mm and? mm, more particularly of a distance between% and = mm,

- The position of the hump or needles is axially downstream of the leading edge of the blades and: or axially upstream of the trailing edge of the blades,

- The aerator is a core and the assembly is preferably provided with return springs, The core can deform the irole, or act on the needles, directly or indirectly, 'lternatiement any other mo (in méani) ue can be provided such as pistons, leers or other, return springs can allow, if necessary, the return to a retracted position or the

2018/5834

BE2018 / 5834 return to a projecting position. 21s can be flush with the ferrule or engage in a housing of the ferrule.

Several are ative seated by a pommel or a parking rod. @a toothed crown can be swiveled around the eye of the ferrule. @ne rod can omit various ielles articulations between them.

'alternatively several souls are independently activated by respective letri) ue motors.

The actuator can be pneumatic or (hydraulic). @ An inflatable bitter can be pressurized to distort the shell or act on the needles. @n vrin (drauli) ue moving A pusher can alternatively be provided.

The aerator is letromani) ue or pi8oletri) ue.

’Together includes a number of ationists separately and: or ironically dals. + ei makes it possible to locate several proturans in an inter-linked space but also in a certain way of * displacing - a proturan by striking several aeronauts simultaneously, for example one aerator) which retracts the needles and another) which deploys other neighboring needles.

The invention also has for o4et an ompressor 0or alternatively a turine1 in particular pressure washer for turomaine in particular turbojet of aircraft occupying the whole according to one of the embodiments eposs idessus and omprenant an annular range of aues statori) ues the others being supported by the shell the aues including a first aue with a surface etrados and a second aue with a surface intrados the needles or the loale deformation of the ferrule projecting from the surface ais (mtri) ue ironfrentiement between the etrados and the lower surface.

5 According to an advantageous embodiment of the invention, the compressor omits at least in) uante) uatrevingt or ent aues.

5 According to an advantageous mode of the invention, the supercharger omits a plurality of aerationers, ironically essentially spaced from one another and from

2018/5834

BE2018 / 5834 mo (control set to control actuators regularly spaced from each other angularly among the plurality of actuators in a s way (according to the conditions in ol it is not necessary to actuate all the actuators but in the case where only one part of the actuators is actuated it contains) that this part is homogeneously distributed angularly around the ae of the compressor 'inention also has for o4et a method of controlling a compressor such) ue describes above the method comprising a step of detecting detachment air lu to the surface of the ais (metric) surface and a control step in the event of detachment of the actuator to bring the plurality of needles or the protruding osseous surface of the ais (metric) to detection a detachment can be carried out using a pressure sensor or parietal rottement 'insi autonomously the turoreactor can detect and correct the detachments of the lu n case of circumferential non-homogeneous lu In fact, only certain portions of the lu can give rise to detachment and the actuators controlled individually can project the needles or the bone in a non-homogeneous manner circumferentially, and in general the aantageu modes of ca) ue o4 and of the intention are also applied to other o4ets of the invention + a) eu o4et of the invention is cominal to the other o4ets and the o4ets of the invention are also cominal to the embodiments of the description) which in addition are cominal between eu according to all the tecni combinations ) less possibilities) the opposite is not explicitly mentioned 'advantages brought

Binention allows you to crop the lu in the passage and create a contouring d (nami) ue ie ie) ui can vary during the operation of the turoreactor% r & $ e! Escription! Es! Essins + certain aspects or advantages associated with the invention the glow of the igures among the) uelles 9 a igure% represents an aial turomacine according to the invention>

2018/5834

BE2018 / 5834 o

Figure = is a diagram of a turbomachine compressor according to the invention> Figures # and C illustrate a plan view dBun inter-blade passage according to the invention according to two needle positions>

The figure <represents an example of a profile of the needles seen transversely the ae of the compressor>

The figure ? represents an example of a profile of the needles seen perpendicularly to the compressor air>

Figure D represents a view of a group of needles according to a ra (on>

Figures & and E show two configurations of an inter-blade passage>

The figures% $ and %% illustrate the process of controlling the contouring of (nami) ue

Description! Es mo! Es! E réaisation, ans description) ui will follow the terms * internal - and * etern - return a positioning with respect to the rotation ea of a aial turbomachine

The aial direction corresponds to the direction along the ea of rotation of the turbomachine The radial direction is perpendicular to the ea of rotation Upstream and downstream are in reference to the main direction of flow of the fluid in the turbomachine

The width is measured along the circumference the length is measured aial and the height is measured radially

The drawings do not respect a given scale and certain dimensions are lightened to highlight certain aspects of the invention, in particular the thickness of the needles or their form factor 0 thickness over length1

The figure% represents in a simplified manner a 2l aial turbomachine is here a double-turbojet engine The turbojet engine = comprises a low-pressure compressor C a high-pressure compressor? a combustion chamber & and one or more turbines% $ n operating the mechanical power of the turbine% $ transmitted via the central shaft 4us) u to the rotor% = sets in motion the two compressors C and? + the latter have several rows of rotor blades associated with rows of stator blades The rotation of the rotor around its ae of rotation% C thus makes it possible to generate a

2018/5834

BE2018 / 5834 air flow and gradually compress the latter juice) at the entrance to the combustion chamber &.

@n commonly designated inlet fan or soulante%? is coupled to the rotor% = and generates an air lu) ui splits into a primary lu% & crossing the various aforementioned levels of the turbomachine and into a secondary lu = $ passing through an annular duct 0partially represented1 along the machine to then re-join the primary lu at the turbine outlet.

The secondary can be accelerated so as to generate a thrust reaction necessary for the flight of an aircraft. The primary% & and secondary = $ lu are annular lu coaiau and fitted one into the other. They are channeled through the casing of the turbomachine and: or of the ferrules.

a igure = is a sectional view of a low pressure compressor of an aial turbomachine such as that of igure%. Fn can (observe part of the soulante%? And the separation nozzle == of the primary lu% & and of the secondary lu = $.

he rotor% = includes several rows of rotor blades) ues = C in this case three. 2l can be a bladed monobloc drum or include dovetailed vanes. es rotori) ues = C can extend radially from an individual platform or from an internal crown = <of the rotor% =.

he low pressure compressor C includes several rectifiers in this case) uatre) ui each contain a row of statori vanes) ues = ?.

are rectifiers associated with year%? or to a row of rotor vanes) to straighten the air lu so as to convert the speed of the lu into pressure, in particular static pressure.

es statori) ues =? extend essentially radially from an outer casing = & and can be connected and immobilized using aes # $.

They cross radially the primary lu% &. Their blades can pass through the annular wall of the outer casing = &. 'within the same row the statori) ues =? are regularly spaced from each other and have the same angular orientation in the line. their strings can

2018/5834

BE2018 / 5834 have a fixed inclination in relation to% C turnover tax. vantagely, the blades of the same row are identi) ed and aligned.

, the internal iroles # = can be suspended from the internal ends of the stator vanes = ?. he internal ferrules # = can cooperate in an extended manner with the rotor% =.

@n C $ annular box integrated or attached to the internal shell # = may contain an actuator to modulate a protuberance in the air flow% &. The C $ box can be made of two semi-circular half-boxes assembled around the bladed drum% =. The C $ box can also be made in one piece.

Figure # represents, on its right side, a sectional view perpendicular to the% C axis. Fn (see the internal shell # = thus) ue the statori vanes) ues = ?. a internal ferrule # = has a surface #C axis (metri) ue, that is s (metric of revolution around the axis% C. a surface #C can be locally c (lindri) ue or coni) ue. The C $ box secured to the ferrule # = accommodates a cam C =) which is movable in rotation around its C # axis, itself parallel to the% C axis. e box C $ includes radial holes 0 not shown 1 to accommodate a shaft carrying the cam C = and allowing it to rotate. @n example of mo (in drive of the cam is illustrated here with a toothed crown CC) ui rotates the cam, integral with a pinion C ?. The compressor can be fitted with several C = cams, on) uel) uesuns or in any inter-blade spaces. with crown CC it is possible to modify in a s (ncrone the position of all the cams C = of the same annular row.

'alternatively, ca) ue cam can be driven individually by suitable mo (ens such as for example an electric motor).

e Control wiring and: or power supply can be brought into the box C $ via a central portion of the turbojet, or via a structural arm 0 * strut -1 or a blade =? hollowed out1 for this purpose.

, in this example, the cam operates a plurality of needles <$. he needles <$ penetrate through holes ## fitted in the shell # =. orifices ## can serve as a guide for needles <$. cam profile and lengths

2018/5834

BE2018 / 5834 needles <$ are such) that a general bump-like protuberance can be obtained by projecting from the ferrule # =. @ne cam can activate at least <, at least% $ or at least = $ needles es needles <$ are sufficiently close to each other to have an effect on the air flow similar to a continuous contouring bump or hollow.

cam C = can have a nonc (lindri) profile in the circumferential direction and possibly a nonlinear profile in a sectional view to actuate independently several needles located aial moon behind the other. @n eample of this is given on the partial section 2229222 on the left part of figure #.

Figure # represents the needles <$ in a retracted position. 'pr.s rotation of the cam C = the needles <$ are placed in a projecting position shown in figure C., the return springs <= allow to return the needles <$ in the retracted position after) the cam is returned to its position in figure #.

5According to the profile of the cam C = and the length of the needles <$ it is possible to choose an infinite number of protruding positions for the needles. 'To this end, the cam C = and possibly the crown CC can be controlled in position by means (adapted to motor: sensors step 1).

The figure <represents an example of a plurality of needles <$ in a parallel cross-section of the line% C. a tip <C 0or the distal end1 of the needles <$ is profiled to gradually deflect the fluid and then bring it back to the ferrule # =. a figure <also illustrates the fact) that the thicknesses of the 0diameter needles if they are c (lindri) ues1 may vary.

a figure? is a perpendicular section lae% C. with point <C of needles <$ can also be profiled in this circumferential direction.

5 on figures <and? we also observe) that the author of) the needles <$ overhang the shell # = is not identi) ue for all the needles so as to form a bump.

2018/5834

BE2018 / 5834

5 in Figure?, The needles are shown as parallel to each other. They can alternatively be perpendicular to the axis% C and therefore be at any point normal the surface ais (metri) ue #C e la irole # =.

Figure D is a radial view of the ferrule # =. In this example, the needles <$ have a profile similar to that of a blade, that is to say with a lower side and a lower side. Alternatively, the needles <$ can have a circular or oval section.

the position of the needles <$ is preferably set back downstream from the leading edges of the blades, materialized by a broken line in FIG.

a figure & es) uisse another example of ferrule # = receiving two blades = ?, observed axially. In this example, the ferrule # = includes a portion? $ of less thickness.

’Portion thickness? $ Can be reduced from% $ to C $; the thickness of the shell # =. a portion? $ can extend circumferentially over more than% $; of the inter-blade distance and can extend axially over more than half the axial length of the blades. Circumferential extent of the portion? $ Can vary axially to reduce progressively downstream.

ors) ue the engine warms up, the portion? $ tends to expand more) ue the rest of the shell # =. Figure E illustrates this expansion. 2l therefore a protuberance in the form of a bump is created? =.

he thickness reduction reduction is such that the detachment of the air flow is lessened. 'insi, depending on the material) ui composes the shell and operating temperatures at) uelles it is appropriate to reduce the separation of the flow, it is easy to establish the necessary thickness reduction. The author of the target bump is $, $ <mm, or $,% mm, or $, <mm, ou = mm.

dilation is therefore operated d (nami) uement and automati) uement, depending on the engine operating temperature, and in particular the temperature of the inter-blade surface.

5i the examples of figures & and E can be considered as alternatives to the use of the needles of the previous figures, the two technical solutions can be combined and implemented on the same

2018/5834

BE2018 / 5834 compressor, on the same annular row of blades, see on the same inter-blade passage, the needles <$ being potentially housed in the shell # = in the thinner 8one? $

The figure% $ represents the s (stem allowing to control d (nami) uement the contouring @n actuator C = apply) an eort, either directly on the ferrule # =, or on needles <$) which come protruding from the ferrule # = + and actuator C = is controlled by a mo (in drive like a crown or a motor, scémati) uement represented here by the part CC The movement of the mo (in drive CC is controlled by a controller D $ + e last receives information from one or more D = sensors, for example arranged in the air flow and measuring the pressure and: or the parietal friction in the vicinity of the shell # = The D $ controller is configured to deduce from the measurements of the sensors D = if a detachment of the fluid takes place and to activate the mo (DC drive set as a consequence) The mo (DC drive set cease to be actuated or are actuated in the opposite direction 0for reduce the bump or retract the needles <$ 1 depending on the data detected by the D = and anal sensors (p ar the controller D $ 'insi, when) that the protuberance created in the flu acts as expected, the CC drive mo can stop their movement and keep their position

When) a detachment reappears for example if the operating point of the turbojet engine has changed, the controller D $ adjusts the protuberance accordingly

The figure %% is a diagram illustrating the steps of the method according to the invention @ a step% $$ of detection of a detachment is carried out in an inter-blade passage When) a detachment is detected, a step% $ = aims to set the corresponding actuator in motion to create a bump 0 when) the actuator acts directly on the ferrule1 or to put the needles protruding

The steps% $$ and% $ = can be done independently in any of the inter-blade spaces. Detection can alternatively be done at a single measurement point per compression stage. The actuators can be all

2018/5834

BE2018 / 5834 ordered or only some of them, for example é) reusable angularly distributed to maintain a homogeneous air flow.

es% $$ and% $ = can be performed continuously or se) uentially

Hien) ue the preferred embodiments are illustrated for an internal stator irole, the lessons given in the present application are applicable to an external irole or rotor iroles, the protuberances in the air flow being able to be useful from other places ) eu on the external surface of an internal tube. n this sense, the intention is not limited to internal iroles and stator vanes.

The various figures illustrate different aspects of the intention. / ous these aspects can be combined or isolated, according to all the possible combinations except that) they are explicitly excluded in the paragraphs above.

Claims (1)

Re $ en! Ications %. Assembly for turbomachine 0 = 1, comprising a ferrule 0 # = 1 provided with an axis (metric) surface 0 # C1 for guiding an air flow 0% & 1, the assembly being characterized in that) it includes a plurality of needles 0 <$ 1 and an actuator 0C = 1 for moving the needles 0 <$ 1 between at least two positions, one of which is in the position where the needles 0 <$ 1 protrude from the axis guide surface ( metri) ue 0 # C1. =. Assembly according to claim%, characterized in) that the plurality of needles 0 <$ 1 is composed of needles 0 <$ 1 parallel to each other and: or extending perpendicularly to the axis 0% C1 of s (metric of the ferrule 0 # = 1. #. Assembly according to one of claims% ou =, characterized in) that the plurality of needles 0 <$ 1 comprises needles 0 <$ 1 distributed circumferentially and: or radially. C. Assembly according to one of claims% #, characterized in) u in the projecting position, at least two needles 0 <$ 1 overhang the guide surface 0 # C1 of a different height. <. Assembly according to one of claims% C, characterized in that the tip 0 <C1 of the needles 0 <$ 1 is profiled. ? Assembly according to one of claims% <, characterized in) that the needles 0 <$ 1 are provided with heating means. D. An assembly according to any of claims%?, Characterized in) that the needles 0 <$ 1 are made of a flexible material. &. Assembly for a 0 = 1 turbomachine, comprising a ferrule 0 # = 1 provided with a wall having an axis (metric) surface 0 # C1 for guiding an air flow, the assembly being characterized in that) it includes an actuator 0C = 1 for locally deforming the wall so as to make appear a protruding bump from the axis (metric) guide surface. E. Assembly according to one of claims% &, characterized in) that the actuator is a cam 0C = 1 and the assembly is preferably provided with springs 0 <= 1 return. 2018/5834 BE2018 / 5834% $. An assembly according to claim E, characterized in) that it comprises several cams 0C = 1 activated simultaneously by a crown 0CC1 or an actuating trinle. %%. Assembly according to claim E, characterized in that) it comprises several cams 0C = 1 independently activated by electric motors) respected. % =. Assembly according to one of the claims% %%, characterized in that) the actuator is pneumatically) or (hydraulically) controlled. % #. Assembly according to one of the claims% %%, characterized in that) the actuator is electromaneti) uely controlled. %VS. Assembly according to one of the claims%% #, characterized in that) it comprises several actuators aially and: or circumferentially offset. % <. + low pressure 0C1 compressor for turbomachine 0 = 1 comprising an annular row of stoves 0 =? 1 statori) ues and characterized in) uil comprises an assembly according to one of the claims%% #, the blades being supported by the ferrule 0 # = 1 , the blades 0 =? 1 comprising a first blade 0 =? 1 with a surface surface, and a second blade 0 =? 1 with a surface surface, the needles 0 <$ 1 or the bump 0? = 1 coming protruding from the surface ais (metric) 0 # C1 of the shell 0 # = 1 circumferentially between letrados and lintrados. % ?. + 0C1 compressor according to claim% <, characterized in that) it comprises a plurality of actuators 0C = 1 arranged circumferentially spaced from each other and mo (control sets 0D $ 1 for controlling actuators 0C = 1 evenly spaced anularly each other among the plurality of actuators in a s (ncrone. % D. 3 compressor control method according to claim% <or% ?, comprising a step 0% $$ 1 for detecting the detachment of air lu at the surface area ais (metric) 0 # C1 and a control step 0% $ = 1, in the event of detachment, from the actuator 0C = 1 to bring the plurality of needles 0 <$ 1 or the hump protruding from the surface (metric).