EP2143956A2 - Flow work machine with groove on a running gap of a blade end - Google Patents

Abstract

The machine has a row of blades (5) arranged in a main flow path. An annular groove (7) runs in a circumferential direction of the machine. An extension of the groove in the circumferential direction is large as compared to an extension of the groove in a meridional flow direction. A cross-sectional area of the groove departs from a parallelogrammic shape in a meridional view of the machine, and is inclined in an upstream direction due to a contour. A centroid of the cross-sectional area of the groove is positioned upstream of a center of a groove aperture (12) on the path.

Description

The invention relates to a fluid flow machine according to the features of the preamble of claim 1.

In particular, the invention relates to a fluid power machine having a main flow path defined by a hub and a housing in which at least one row of blades is arranged which forms a nip with respect to the hub or housing.

The aerodynamic load capacity and efficiency of fluid flow machines, such as fans, compressors, pumps and fans, is limited in particular by the growth and separation of boundary layers in the rotor and stator tip region near the housing or hub wall. This results in blade rows with running gap at higher load to Rückströmerscheinungen and the occurrence of instability of the machine.

1. a.) aus Schlitzen/Öffnungen und Kammern im Gehäuse über dem Rotor bestehen; die Öffnungen haben dabei stets Rechteck- beziehungsweise Parallelogrammform,
2. b.) aus Schlitzen im Gehäuse, die im Wesentlichen in Strömungsrichtung orientiert sind und eine schlanke Form mit einer in Umfangsrichtung der Maschine betrachtet geringen Ausdehnung besitzen,
3. c.) Umfangsnuten mit rechteckigem oder parallelogrammförmigem Querschnitt.

According to the state of the art, fluid flow machines either have no special features for remedying this area or, as a countermeasure, so-called casing treatments are used which:

1. a.) consist of slots / openings and chambers in the housing over the rotor; the openings always have a rectangular or parallelogram shape,
2. b.) of slots in the housing, which are oriented substantially in the flow direction and have a slim shape with a small extent viewed in the circumferential direction of the machine,
3. c.) circumferential grooves with a rectangular or parallelogrammförmigem cross section.

These include known solutions, which are disclosed in the following documents:

US 2005/0226717 A1 . EP 0 754 864 A1 . DE 101 35 003 C1 and DE 103 30 084 A1 ,

A sketch of conventional slots and grooves 10 is in the 1a and 1b given.

Simple concepts known from the prior art of casing treatments in the form of slots and / or chambers in the annular channel wall offer an increase in the stability of the fluid flow machine. However, this is achieved due to the unfavorably chosen arrangement or shaping only at loss of efficiency. The known solutions partly take up a large space at the periphery of the annular channel of the fluid flow machine or are only partially effective due to their shape (eg simple parallelogram-shaped peripheral housing grooves) and are limited to the arrangement of a rotor blade row surrounded by a housing.

The present invention has for its object to provide a fluid flow machine of the type mentioned, which has an effective boundary layer influence in the blade tip area while avoiding the disadvantages of the prior art.

According to the invention the object is achieved by the feature combination of the main claim, the subclaims show further advantageous embodiments of the invention.

Thus, according to the invention, an optimized embodiment of the groove is described by means of which the flow conditions in the region of the blade edge and the running gap can be optimized.

In particular, the invention relates to a portion of the annular channel of a fluid flow machine, in the region of a blade row with free end and running gap, in which a substantially extending in the circumferential direction of the machine groove is provided with flow-favorable cross-section, wherein the groove cross section has no parallelogram shape and by its contouring upstream is oriented. The arrangement relates to arrangements with a running gap and relative movement between the blade end and the main flow path boundary, both on the housing and on the hub.

The present invention thus relates to fluid flow machines such as fans, compressors, pumps and fans, in both axial, semi-axial and radial designs. The working medium or fluid may be gaseous or liquid.

The turbomachine may include one or more stages, each having a rotor and a stator, in some cases the stage is merely formed by a rotor.

The rotor consists of a number of blades, which are connected to the rotating shaft of the machine and deliver energy to the working fluid: The rotor can be designed with or without shroud at the outer blade end.

The stator consists of a number of stationary blades, which can be designed on the hub side as the housing side with a fixed or free blade end.

The rotor drum and the blading are usually surrounded by a housing, in other cases, for. As in propellers or propellers, no housing exists.

The machine can also have a stator in front of the first rotor, a so-called leading wheel. At least one stator or Vorleitrad may - unlike the immovable fixation - be rotatably mounted to the angle of attack change. An adjustment is made for example by a spindle accessible from outside the annular channel.

In a particular embodiment, the turbomachine may have at least one row of adjustable rotors.

Alternatively, the turbomachine according to the invention may have two counter-rotating shafts in multiple stages, so that the rotor blade rows change the direction of rotation from stage to stage. There are no stators between successive rotors.

Finally, the fluid flow machine can alternatively have a bypass configuration such that the single-flow annular channel divides behind a certain row of blades into two concentric annular channels, which in turn accommodate at least one additional row of blades.

Fig.2 shows examples according to the invention relevant flow machines.

Fig. 1a:

eine Skizze des Standes der Technik, Rotorgehäusestrukturierung;

Fig. 1b:

eine Skizze des Standes der Technik, Rotorgehäuse, Umfangsnuten;

Fig. 2:

Beispiele erfindungsgemäß relevanter Strömungsarbeitsmaschinen;

Fig. 3:

eine erfindungsgemäße Umfangsnut, Ansicht im Meridianschnitt;

Fig. 4a:

eine erfindungsgemäße Position der Umfangsnut im Meridianschnitt;

Fig. 4b:

eine erfindungsgemäße Position der Umfangsnut im Meridianschnitt, Beispiele;

Fig. 4c:

eine erfindungsgemäße, günstige Ausführung mit Anstreifbelag;

Fig. 4d:

eine erfindungsgemäße, günstige Ausführung mit Anstreifbelag und Ausnehmung am Schaufelende;

Fig. 5a:

eine erfindungsgemäße Umfangsnut im Meridianschnitt, Formkenngrößen,

Fig. 5b:

eine erfindungsgemäße Umfangsnutformen im Meridianschnitt;

Fig. 5c:

weitere erfindungsgemäße Umfangsnutformen im Meridianschnitt;

Fig. 5d:

weitere erfindungsgemäße Umfangsnutformen im Meridianschnitt;

Fig. 5e:

weitere erfindungsgemäße Umfangsnutformen im Meridianschnitt;

Fig. 6a:

erfindungsgemäße Umfangsnutformen in der Ansicht Q-Q;

Fig. 6b:

weitere erfindungsgemäße Umfangsnutformen in der Ansicht Q-Q;

Fig. 6c:

weitere erfindungsgemäße Umfangsnutformen in der Ansicht Q-Q;

Fig. 6d:

weitere erfindungsgemäße Umfangsnutformen in der Ansicht Q-Q;

Fig. 6e:

weitere erfindungsgemäße Umfangsnutformen in der Ansicht Q-Q;

Fig. 6f:

weitere erfindungsgemäße Umfangsnutformen in der Ansicht Q-Q;

Fig. 7a:

eine erfindungsgemäße Umfangsnut mit Unterbrechung;

Fig. 7b:

eine erfindungsgemäße Umfangsnut mit geformter Unterbrechung;

Fig. 8a:

erfindungsgemäße Umfangsnuten mit internem Umlenkmittel, Meridianansicht;

Fig. 8b:

eine erfindungsgemäße Umfangsnut mit internem Umlenkmittel (parallel);

Fig. 8c:

eine erfindungsgemäße Umfangsnut mit internem Umlenkmittel (schräg);

Fig. 8d:

eine erfindungsgemäße Umfangsnut mit internem Umlenkmittel (schräg und konturiert);

Fig. 8e:

eine erfindungsgemäße Umfangsnut mit internem Umlenkmittel (schräg und profiliert).

In the following the invention will be described by means of embodiments in conjunction with the figures. Showing:

Fig. 1a:

a sketch of the prior art, rotor housing structuring;

Fig. 1b:

a sketch of the prior art, rotor housing, circumferential grooves;

Fig. 2:

Examples of relevant flow working machines according to the invention;

3:

a circumferential groove according to the invention, view in meridian section;

Fig. 4a:

a position according to the invention of the circumferential groove in the meridian section;

Fig. 4b:

a position according to the invention of the circumferential groove in the meridian section, examples;

4c:

an inventive, cheap version with squint coating;

4d:

an inventive, favorable design with squint and recess at the blade end;

Fig. 5a:

a circumferential groove according to the invention in the meridian section, shape characteristics,

Fig. 5b:

a Umfangsnutformen invention in meridian section;

Fig. 5c:

further Umfangsnutformen invention in meridian section;

Fig. 5d:

further Umfangsnutformen invention in meridian section;

Fig. 5e:

further Umfangsnutformen invention in meridian section;

6a:

circumferential groove shapes according to the invention in the view QQ;

Fig. 6b:

further circumferential groove shapes according to the invention in the view QQ;

Fig. 6c:

further circumferential groove shapes according to the invention in the view QQ;

6d:

further circumferential groove shapes according to the invention in the view QQ;

Fig. 6e:

further circumferential groove shapes according to the invention in the view QQ;

Fig. 6f:

further circumferential groove shapes according to the invention in the view QQ;

Fig. 7a:

a circumferential groove according to the invention with interruption;

Fig. 7b:

a circumferential groove according to the invention with a shaped break;

8a:

circumferential grooves according to the invention with internal deflection means, meridian view;

8b:

a circumferential groove according to the invention with internal deflection (parallel);

8c:

a circumferential groove according to the invention with internal deflection (oblique);

8d:

a circumferential groove according to the invention with internal deflection (oblique and contoured);

8e:

a circumferential groove according to the invention with internal deflection (oblique and profiled).

The Figure 3 shows the inventive solution of a row of blades 5 with free end and running gap 11 and a circumferentially extending groove 7 in the region of the running gap 11, shown in the plane defined by the axial direction x and the radial direction r meridian plane.

The running gap 11 separates the blade tip from a component belonging to the main flow path on the hub 3 or the housing 1 of the fluid flow machine.

1. 1.) rotierende Schaufel an stehendem Gehäuse;
2. 2.) ruhende Schaufel an rotierender Nabe;
3. 3.) ruhende Schaufel an rotierendem Gehäuse;
4. 4.) rotierende Schaufel an stehender Nabe.

Between the blade tip and belonging to the main flow path component is a rotating relative motion. The presentation thus applies equally to the following arrangements:

1. 1.) rotating blade on stationary housing;
2. 2.) stationary blade on rotating hub;
3. 3.) stationary blade on rotating housing;
4. 4.) rotating blade on standing hub.

The main flow direction is shown with a thick arrow. Upstream of the row of blades with a running gap, as indicated here by dashed lines, can be another row of blades.

The leading edge point of the blade 5 at the nip 11 is designated A and the trailing edge point of the blade at the nip is designated B.

The opening 12 of the groove 7 at the edge of the main flow path is bounded by the starting point C and the end point D. From the slot opening 12 of a recessed into the housing 1 and in the hub contour recess is provided which has an upstream inclination. The extent of the groove 7 in the circumferential direction according to the invention is large compared to the extension of the groove 7 in meridional flow direction. The groove 7 according to the invention can therefore be provided either on the entire circumference of the machine or only on a portion of the circumference.

The shape of the groove 7 according to the invention chosen in this illustration is to be considered by way of example and as representative of a number of groove shapes with upstream inclination which are possible according to the invention and which are further explained in further figures.

Also advantageous according to the invention is the trivially dissipative solution of a multiple arrangement of grooves 7 according to the invention in the region of a blade end with gap. Such an arrangement is in Figure 3 the example of two more (here dotted indented) grooves 7 shown. For the sake of simplicity, however, only one groove 7 is shown in further following images and views.

Finally, the representation still contains the view Q-Q, which is used in further illustrations of solutions according to the invention.

The 4a shows the groove 7 according to the invention in an enlarged view, again in the plane defined by the axial direction x and the radial direction r meridian plane. Contained are now only the contour of the groove 7, the relevant part of the main flow path boundary and a blade end with gap 11. Also shown are the corner points of the blade end A and B, and the Nutöffnungsstartpunkt C and the Nutöffnungsendpunkt D.

The dashed line through the blade tip corner points A and B specifies the reference direction for further characteristic sizes of a groove according to the invention. All further dashed auxiliary lines drawn extend either parallel or perpendicular to the reference line A-B. Thus, a parallel to A-B passes through the groove opening end point D. In addition, a perpendicular to A-B passes through the groove opening start point C and the center of gravity of the groove cross-sectional area S outside the main flow path.

The groove opening center M is defined as a point on the auxiliary line through the point D, viewed in the reference direction A-B at half the distance between the points C and D.

According to the invention, the cross section of the groove 7 deviates substantially from a parallelogram shape and is inclined upstream due to its contouring. This is ensured inter alia by the fact that the center of gravity S of the groove cross-sectional area is provided by an amount d> 0 upstream of the center M of the slot opening.

The inventive positioning of the groove 7 in the region of the blade end is by the given between the points A and C in the reference direction AB distance VN in relation to the meridional chord length at the blade tip Lm as follows: -0.25 <VN / Lm <0.95. Thus, the groove start point may be no more than 25% of the meridional vane chord length upstream of the leading edge point A and at most 95% of the meridional vane chord length downstream of the leading edge point A.

A positioning according to -0.15 <VN / Lm <0.35 is advantageous according to the invention. According to the invention, a positioning according to -0.15 <VN / Lm <0.15 is particularly favorable.

The Fig. 4b shows four examples of positioning of grooves according to the invention.

The Fig. 4c shows three examples of a groove 7 according to the invention in the event that a Schaufelanstreifbelag is provided in the main flow path boundary in the region of the running gap. A particularly favorable solution according to the invention comprises that, as shown, the abradable coating is provided only within a subsection of the blade clearance path width, the abradable coating within this subsection forms a smooth and uninterrupted surface on the main flow path boundary, and a groove according to the invention forms the abradable coating upstream and / or downstream limited that the blade tip corner point A and / or the blade tip corner point B are in a not covered with squint area. This is for all three representations of Fig. 4c true, where the representation top left a groove 7 in the blade leading edge, the representation top right a groove 7 in the region of the front and rear edge, and the bottom left representation of a groove 7 in the region of the leading edge with paragraph (here even with an overlap from slot opening start edge and blade end transverse to meridian flow direction).

The Fig. 4d shows similar configurations according to the invention with abradable coating, in which case the abradable coating is completely enclosed at the edges of the groove 7 at its edges by the material of the main flow path boundary forming member. In this case, it is favorable according to the invention, where the blade end is directly opposite the material of the component forming the main flow path boundary, to provide a recess at the blade end which locally avoids scratching of the blade end.

• Die Linie L1 verläuft parallel zu A-B durch den Nutöffnungsendpunkt D.
• Die Linie L2 verläuft parallel zu L1 durch den Nutöffnungsstartpunkt C.
• Die Linie L3 verläuft parallel zu L1 tangential entlang der Nutkontur, sodass sie erfindungsgemäß mindestens einen Punkt G an einem Ort bei maximaler Eindringtiefe h mit L3 gemeinsam hat.
• Die Linie L4 verläuft senkrecht zu L1 tangential entlang der Nutkontur, sodass sie erfindungsgemäß mindestens einen Punkt F an einem Ort bei maximaler Stromauf-Überhang m mit L4 gemeinsam hat.
• Die Linie L5 verläuft senkrecht zu L1 tangential entlang der Nutkontur, sodass sie erfindungsgemäß mindestens einen Punkt E an einem Ort bei maximalem Stromab-Überhang n mit L5 gemeinsam hat.
• Die Linie L6 verläuft senkrecht zu L1 durch den Nutöffnungsstartpunkt C und teilt die Querschnittsfläche der Nut erfindungsgemäß in zwei Teilflächen auf: die stromauf von L6 befindlichen Fläche AF (dick schraffiert) und die stromab von L6 befindlichen Fläche AR (dünn schraffiert).

The Fig. 5a shows the groove 7 according to the invention in an enlarged view with the definition of their shape characteristics, again in the plane defined by the axial direction x and the radial direction r meridian plane. The groove 7 according to the invention is defined by an arrangement of six auxiliary lines, for which certain conditions apply. The auxiliary lines run either parallel or perpendicular to the reference direction AB:

• The line L1 runs parallel to AB through the slot opening end point D.
• The line L2 runs parallel to L1 through the slot opening start point C.
• The line L3 runs parallel to L1 tangentially along the groove contour, so that according to the invention it has at least one point G at one location at maximum penetration depth h with L3 in common.
• The line L4 runs perpendicular to L1 tangentially along the groove contour, so that according to the invention it has at least one point F at a location at maximum upstream overhang m with L4 in common.
• The line L5 runs perpendicular to L1 tangentially along the groove contour, so that according to the invention it has in common at least one point E at a location with maximum downstream overhang n with L5.
• The line L6 runs perpendicular to L1 through the Nutöffnungsstartpunkt C and divides the cross-sectional area of the groove according to the invention in two sub-areas: the upstream of L6 surface AF (shaded thick) and located downstream of L6 surface AR (shaded hatched).

The center of gravity of the entire groove cross-sectional area (AF + AR) is also shown here as point S, as well as the Nutöffnungsmittelpunkt M and provided between S and M distance d.

The distances k, h, m, n, d have a positive sign in the indicated arrow direction.

• w / Lm < 0,2
• h/w < 10
• m / w > 0,1
• AF / AR > 0,1
• d / w > 0,05
• Betrag (k / w) < 2

Finally, for a groove according to the invention, the following further features apply jointly:

• w / Lm <0.2
• h / w <10
• m / w> 0.1
• AF / AR> 0.1
• d / w> 0.05
• Amount (k / w) <2

The Fig. 5b shows by way of example four groove shapes according to the invention in an enlarged representation in the plane defined by the axial direction x and the radial direction r meridian plane. For better orientation of the viewer, the in Fig. 5a also described guidelines. Also, the hatched part surfaces of the groove are included in each image part. It becomes clear here that, within the above-described inventive definition of the groove in the meridian view, different shapes, consisting of a combination of straight and curved contour sections, can be provided.

In this case, in particular, an inclination of the groove contour (0 ° <γ F <90 °) pointing at least in sections in the upstream direction is advantageous in the region of the partial surface AF, see Fig. 5b , Picture section top left.

It is particularly favorable if the angle of inclination of the groove contour on the partial surface AF assumes, at least in sections, values in the range between 15 ° and 55 ° (15 ° <γ R <55 °). This applies in particular to the contour inclination in the slot opening start point C.

Further advantages arise when the groove contour is formed on the partial surface AF rectilinear or concave (relative to the interior of the groove).

Furthermore, an inclination of the groove contour in the region of the partial surface AR pointing at least in sections in the upstream direction is advantageous (0 <γ R <90 °), see Fig. 5b , Picture part at the bottom left.

It is particularly favorable if the angle of inclination of the groove contour on the partial surface AR assumes values in the range between 15 ° and 55 ° at least in sections (15 ° <γ R <55 °). This applies in particular to the contour inclination in the slot opening end point D.

Further advantages result if the groove contour is formed on the partial surface AR rectilinear or concave (relative to the interior of the groove).

The FIGS. 5c and 5d show, by way of example, four further groove shapes according to the invention in an enlarged representation in the meridian plane. Here, the groove contour is formed either by a pure traverse or by a combination of arc and traverse.

While the FIGS. 5a to 5c Show examples of grooves according to the invention, in which the Nutöffnungsstartpunkt C and the Nutöffnungsendpunkt D are on the same auxiliary line (ie, the offset k is equal to zero) shows the Fig. 5e Examples of groove configurations with a positive or negative offset k according to the invention.

The Fig. 6a shows two solutions according to the invention a groove in the view QQ, in Fig. 3 is drawn. Shown is a view of the surface of the main flow path boundary in the plane spanned by the circumferential direction u and the meridional direction m. Shown here is only an outbreak of Hauptströmungspfadberandung, unwound in the plane of the drawing. The profiles of two adjacent blade ends of the blade row are shown in dashed lines. The main flow runs from left to right, as indicated by the thick arrow.

The left part of the Fig. 6a shows a groove 7 according to the invention, which is provided exactly in the circumferential direction with the same groove cross-sectional shape along the entire circumference of the machine in the Hauptströmungspfadberandung. The lines formed by the groove opening start points C and groove opening end points D are respectively labeled LC and LD. The hidden edge, which results as a connection of all Nutfrontpunkte F is denoted by LF and dotted marked. The parallel, along the entire circumference provided course of the three lines LF, LC and LD represents the simplest variant of the invention Solution. The distance between two adjacent blades, the so-called blade pitch, has, as also indicated in the image, the amount t directly at the gap.

The right part of the Fig. 6a shows a groove 7 according to the invention in the form of a circumferential groove 13 which is provided substantially in the circumferential direction and a constant groove cross-sectional shape along the entire circumference of the machine in the Hauptströmungspfadberandung, but according to the invention has a circumferentially varying position of the groove relative to the blade end in meridionalrichtung m. With a certain period f, recurring courses of the groove are particularly favorable. The course of the groove can, as here, be designed to be similar to a sinusoid.

Like the left part of the Fig. 6b shows, it may further be advantageous according to the invention to oscillate only one or two of the three lines LF, LC and LD,
in which case also the cross-sectional shape of the groove (in the limits according to the invention) varies along the circumference. According to the invention, it can be advantageous in terms of flow, design or manufacturing technology to allow at least one of the three lines LF, LC and LD to run polygonal or jagged, see the right side of FIG Fig. 6b , As with the grooves according to the invention described so far, a periodic recurrence of a groove portion, and in particular a periodic recurrence of a groove portion with an entire divisor or an integral multiple of the blade pitch t, is also advantageous.

Also according to the invention is a course of the groove, which is interrupted in the circumferential direction.

The Fig. 6c shows examples according to the invention for an interrupted and an interrupted and offset course of the groove, wherein the edges of the interruption are aligned substantially in the meridional direction m. According to the invention, the illustrated configurations fulfill the condition that the circumferential extent e of a single groove is significantly greater than the width w of the slot opening (possibly varying in the circumferential direction), and in this way a circumferentially slender formation of the groove is provided. Especially It is favorable if the groove length e has at least the size of the blade pitch t (e / t greater or equal to 1).

Also grooves with variable (oblique, curved or oscillating) course of the lines LF, LC and / or LD are according to the invention. Two examples of this are in Fig. 6d shown.

The Fig. 6e Figure 2 shows two further examples of the course along the circumference in the meridian direction of an interrupted groove.

The Fig. 6f Finally shows embodiments of the groove according to the invention, in which the two edges of the groove interruption are on the one hand differently and on the other obliquely aligned to the meridional direction.

The Fig. 7a shows a groove according to the invention with interruption in different views. At the top right of the picture is the groove in the meridian plane, in which the view ZZ and the section XX are marked. View ZZ intersects the blade near the gap and provides a view of the surface of the main flow path boundary and the slot opening. Invisible edges are dotted. The inventive solution with groove interruption shown here comprises an inclination of the interrupting wall in the circumferential direction. This is especially in section XX (see Fig. 7a , bottom right). Section XX shows the case of a main flow path boundary (housing) concavely curved in this view; the present relative direction of movement of the blade end is indicated by an arrow. Of course, the illustrated features of Nutausbrechung also for the case of a convex curved Hauptströmungspfadberandung (hub), not shown here according to the invention. The interruption wall can be inclined in an advantageous embodiment, as shown here, in the circumferential direction such that, starting from the main flow path, an oblique running towards the bottom of the groove in the direction of the relative movement of the blade end is provided. A running in the direction of the blade flow can enter the groove in this way undisturbed. Particularly advantageous according to the invention are inclination angles at the main flow path of δ1 greater than 45 °.

The Fig. 7b shows in an equivalent representation Fig. 7a a further advantageous design of Nutausbrechung. The two sides of the groove interruption have a particularly contoured shape, which has the consequence that the groove interruption in the section XX differs significantly from a simple web-like shape, such that in the (relative) direction of the blade end facing side of the interruption is flat and possibly curved by observing values δ1> 45 °, the bottom of the groove approximates, and the side of the interruption facing the (relative) running direction of the blade end approximates first steep and then rounding out from the main flow path to the bottom of the groove. Here, values of the inclination angle at the main flow path of δ2 between 25 ° and -25 ° are particularly favorable.

The Fig. 8a shows nine examples according to the invention possible configurations of grooves with internal deflection, shown in the meridian view. According to the invention, the internal deflecting means initially constitutes an obstacle within the groove, which interrupts a flow path which is undisturbed and continuous in the circumferential direction in a part of the groove cross-section and causes the flow to be deflected or deflected by its shaping. The free edge of the internal deflection means according to the invention is either completely within the groove (ie, it does not occur over a linear connection of the start and end points of the slot opening C and D in the direction of the main flow out) or it affects the straight-line connection between the points C. and D in part of their course.

The Fig. 8b shows a more detailed representation of a groove according to the invention with internal deflection in three views. Top right is the meridian view showing the groove in cross section. Within the groove, a deflection means is provided between groove bottom and approximately half the groove depth, the free edge of which runs parallel to the auxiliary line through the point D. The view ZZ top left in Fig. 8b shows the course of the groove along part of the circumference and the deflection within the groove, of which the rear half visible, the front half is covered (dotted lines). As the section XX shows, the deflection means here consists of a simple, circumferentially inclined web. Of course, even simpler webs without inclination according to the invention.

The Fig. 8c shows a groove according to the invention with internal deflection means, which is provided starting from the Nutöffnungsstartpunkt C obliquely and with a curved course of the free edge in the upstream part of the groove. As Ansicht ZZ and section XX illustrate, this is also an inclined bridge. As in Fig. 8b Here too, a completely round groove shape without offset between the points C and D (k = 0) is considered as an example.

The Fig. 8d shows a groove according to the invention with internal deflection, which in the meridian view of the in Fig. 8c pictured resembles. However, here, as the view ZZ and the section XX show, a contouring of the deflection means is provided.

The Fig. 8e finally shows a groove according to the invention with internal deflection, which in the meridian view of the in Fig. 8c is similar. However, a slot configuration with offset (k <0) is shown here by way of example. As the view ZZ and the section XX show, a profiling and curvature of the deflection is provided here for better flow management / deflection.

The invention can also be described as follows:

1. a.) alle Hilfslinien parallel oder senkrecht zur Referenzrichtung A-B entlang des Schaufelendes verlaufen,
2. b.) eine Linie L1 parallel zu A-B durch den Nutöffnungsendpunkt D verläuft,
3. c.) eine Linie L2 parallel zu L1 durch den Nutöffnungsstartpunkt C verläuft,
4. d.) eine Linie L3 parallel zu L1 tangential entlang der Nutkontur verläuft, sodass sie mindestens einen Punkt G an einem Ort bei maximaler Nuteindringtiefe h mit L3 gemeinsam hat,
5. e.) eine Linie L4 senkrecht zu L1 tangential entlang der Nutkontur verläuft, sodass sie mindestens einen Punkt F an einem Ort bei maximalem Nut-Stromauf-Überhang m mit L4 gemeinsam hat,
6. f.) eine Linie L5 senkrecht zu L1 tangential entlang der Nutkontur verläuft, sodass sie erfindungsgemäß mindestens einen Punkt E an einem Ort bei maximalem Nut-Stromab-Überhang n mit L5 gemeinsam hat,
7. g.) eine Linie L6 senkrecht zu L1 durch den Nutöffnungsstartpunkt C verläuft und die Querschnittsfläche der Nut in die stromauf von L6 befindlichen Fläche AF und die stromab von L6 befindlichen Fläche AR aufteilt,
8. h.) der Schwerpunkt S der Nutquerschnittsgesamtfläche und der Nutöffnungsmittelpunkt M einen Abstand d aufweisen,
9. i.) zwischen den Randpunkten C und D der Nutöffnung eine Nutöffnungsweite w gegeben ist,
10. j.) zwischen den Hilfslinien L1 und L2 ein Versatz k vorgesehen ist,
11. k.) die Schaufel an ihrem Ende eine meridionale Sehnenlänge Lm besitzt, und wobei Kenngrößen der Nut in folgender Weise festgelegt sind:
    • w / Lm < 0,2 und h / w < 10 und d / w > 0,05 und m / w > 0,1, und
    • AF / AR > 0,1 und Betrag von (k / w) < 2,
    wobei im Bereich der Fläche AR im Abschnitt zwischen dem Nutöffnungsendpunkt D und dem Punkt G bei maximaler Nuteindringtiefe der Neigungswinkel der Nutkontur γ_R ausschließlich Werte zwischen 0° und 90° annimmt,
    wobei im Bereich der Fläche AR in mindestens einem Teil des Abschnitts zwischen dem Nutöffnungsendpunkt D und dem Punkt G bei maximaler Nuteindringtiefe die Nutkontur linear oder konkav (bezogen auf das Innere der Nut) beschaffen ist,
    wobei der Neigungswinkel der Nutkontur γ_R am Nutöffnungsendpunkt D Werte zwischen 15° und 55° annimmt,
    wobei im Bereich der Fläche AF im Abschnitt zwischen dem Nutöffnungsstartpunkt C und dem Punkt F bei maximaler Stromaufausdehnung der Neigungswinkel der Nutkontur γ_F ausschließlich Werte zwischen 0° und 90° annimmt,
    wobei im Bereich der Fläche AF in mindestens einem Teil des Abschnitts zwischen dem Nutöffnungsstartpunkt C und dem Punkt F bei maximaler Stromaufausdehnung die Nutkontur linear oder konkav (bezogen auf das Innere der Nut) beschaffen ist,
    wobei der Neigungswinkel der Nutkontur γ_F am Nutöffnungsstartpunkt C Werte zwischen 15° und 55° annimmt,
    wobei gemeinsam mit der mindestens einen Nut ein Schaufelanstreifbelag als Hauptströmungspfadberandung im Bereich des Laufspaltes vorgesehen ist, wobei der Anstreifbelag nur innerhalb eines Abschnitts der meridionalen Erstreckung des Schaufellaufpfades beziehungsweise Laufspaltes vorgesehen ist, und der Anstreifbelag nach stromauf und / oder stromab von einer Nut derart begrenzt wird, dass mindestens einer der Schaufelkantenpunkte A und B in einem nicht mit Anstreifbelag überdeckten Abschnitt liegen,
    wobei der Anstreifbelag an seinem Übergang zu mindestens einer Nut eine vollständig vom Material des die Hauptströmungspfadberandung bildenden Bauteils eingefassten Rand aufweist, und an mindestens einer Stelle, an der das Schaufelende direkt dem Material des den Anstreifbelag umrandenden Bauteils gegenüber steht, eine Ausnehmung am Schaufelende vorgesehen ist, die lokal ein Anstreifen des Schaufelendes vermeidet,
    wobei die Signaturlinien mindestens einer Nut, d. h. die Frontlinie LF, die Nutöffnungsstartlinie LC und die Nutöffnungsendlinie LD, exakt in Umfangsrichtung entlang der Hauptströmungspfadberandung verlaufen,
    wobei mindestens eine Signaturlinie mindestens einer Nut (Frontlinie LF, Nutöffnungsstartlinie LC, Nutöffnungsendlinie LD) einen entlang des Umfangs in meridionaler Richtung variierenden Verlauf aufweist,
    wobei der entlang des Umfangs in meridionaler Richtung variierende Verlauf der mindestens einen Signaturlinie mindestens einer Nut eine Periodizität aufweist,
    wobei die im Meridianschnitt betrachtete Querschnittsform mindestens einer Nut entlang des Umfangs variiert,
    wobei der Verlauf mindestens einer Nut entlang des Umfangs mindestens einmal vollständig unterbrochen ist,
    wobei benachbarte Enden mindestens einer Nut im Bereich der Unterbrechung in meridionaler Richtung versetzt angeordnet sind,
    wobei die Tiefe h mindestens einer Nut in Richtung der Relativbewegung des betreffenden Schaufelendes kontinuierlich wenigstens über einen Abschnitt ihres Verlaufes zunimmt,
    wobei innerhalb mindestens einer Nut mindestens ein Umlenkmittel vorgesehen ist, das für eine nutinterne Strömung ein örtliches Hindernis darstellt und so beschaffen ist, dass eine Richtungsänderung der Strömung erreicht wird, wobei das mindestens eine Umlenkmittel von der Hauptströmungspfadberandung zurückgesetzt angeordnet ist, derart, dass eine freie Kante des Umlenkmittels höchstens die geradlinige Verbindung der Nutöffnungspunkte C und D in einem Teil ihres Verlaufes tangierend erreicht,
    wobei ein nutinternes Umlenkmittel vorgesehen ist, das im Bereich seiner freien Kante zur besseren Strömungsführung eine Wölbung und/oder Profilierung aufweist.

A fluid flow machine having a main flow path bounded by a hub and a housing, in which at least one row of blades is arranged, wherein a gap is provided on at least one row of blades between a blade end and a main flow path boundary,
wherein the blade end and the Hauptströmungspfadberandung perform a rotating relative movement to each other and in the region of the gap in the Hauptströmungspfadberandung at least one substantially extending in the circumferential direction of the machine groove having flow-favorable cross-section along at least a portion of the circumference, wherein the extension of the groove in the circumferential direction is large compared is the extension of the groove in the meridional flow direction, and wherein the cross-sectional area of the groove as viewed in the meridian view of the fluid flow machine is substantially deviated from a parallelogram shape and inclined upstream due to its contouring wherein the center of gravity of the groove cross-sectional area is provided upstream of the center of the groove opening at the main flow path,
wherein the position of the at least one groove described by the distance VN between the blade leading edge corner A and the slot opening start point C is given by the condition -0.25 <VN / Lm <0.95, where Lm is the meridional chord length at the blade end at the nip .
wherein the position of the at least one groove relative to the blade leading edge is set as follows: -0.15 <VN / Lm <0.35,
wherein the position of the at least one groove relative to the blade leading edge is set as follows: -0.15 <VN / Lm <0.15,
wherein the at least one groove has a strongly upwardly inclined shape whose characteristics are defined in the plane defined by the axial direction x and the radial direction r meridian plane by a network of six auxiliary lines, wherein

1. a.) all auxiliary lines run parallel or perpendicular to the reference direction AB along the blade end,
2. b.) a line L1 runs parallel to AB through the slot opening end point D,
3. c.) a line L2 runs parallel to L1 through the slot opening start point C,
4. d.) a line L3 parallel to L1 runs tangentially along the groove contour so that it has at least one point G at a location at maximum groove penetration depth h with L3 in common,
5. e.) a line L4 perpendicular to L1 runs tangentially along the groove contour, so that it has at least one point F at a location with maximum groove-upstream overhang m in common with L4,
6. f.) A line L5 perpendicular to L1 runs tangentially along the groove contour, so that according to the invention it has at least one point E at a location with maximum groove downstream overhang n in common with L5.
7. g.) a line L6 perpendicular to L1 passes through the groove opening start point C and divides the cross-sectional area of the groove into the surface AF located upstream of L6 and the surface AR located downstream of L6,
8. h.) have the center of gravity S of the groove cross-sectional total area and the Nutöffnungsmittelpunkt M a distance d,
9. i.) between the edge points C and D of the slot opening a slot opening width w is given,
10. j.) an offset k is provided between the auxiliary lines L1 and L2,
11. k.) the blade has at its end a meridional chord length Lm, and wherein characteristics of the groove are defined in the following manner:
    • w / Lm <0.2 and h / w <10 and d / w> 0.05 and m / w> 0.1, and
    • AF / AR> 0.1 and amount of (k / w) <2,
    wherein in the region of the surface AR in the section between the groove opening end point D and the point G at maximum groove penetration depth, the angle of inclination of the groove contour γ _R assumes exclusively values between 0 ° and 90 °,
    wherein in the region of the surface AR in at least part of the section between the groove opening end point D and the point G at maximum groove penetration depth, the groove contour is linear or concave (relative to the interior of the groove);
    wherein the inclination angle of the groove contour γ _R at the groove opening end point D assumes values between 15 ° and 55 °,
    wherein in the region of the surface AF in the section between the slot opening start point C and the point F at maximum current extension, the angle of inclination of the groove contour γ _F assumes exclusively values between 0 ° and 90 °,
    wherein in the region of the surface AF in at least part of the section between the slot opening start point C and the point F at maximum current extension, the groove contour is linear or concave (with respect to the interior of the groove);
    wherein the inclination angle of the groove contour γ _F at the slot opening start point C assumes values between 15 ° and 55 °,
    wherein together with the at least one groove a Schaufelanstreifbelag is provided as Hauptströmungspfadberandung in the region of the running gap, wherein the abradable coating is provided only within a portion of the meridionalen extent of the blade clearance or running gap, and the Anstreifbelag after upstream and / or downstream of a groove is limited in that at least one of the blade edge points A and B lie in a section which is not covered by a squish coating,
    wherein the abradable coating at its transition to at least one groove has an edge completely surrounded by the material of the component forming the main flow path boundary, and a recess at the blade end is provided at at least one point where the blade end directly faces the material of the component surrounding the abradable coating that avoids local scratching of the blade end,
    wherein the signature lines of at least one groove, that is, the front line LF, the groove opening start line LC, and the groove opening end line LD, run exactly circumferentially along the main flow path boundary,
    wherein at least one signature line of at least one groove (front line LF, groove opening start line LC, groove opening end line LD) has a course varying along the circumference in the meridional direction,
    wherein the course of the at least one signature line of at least one groove varying along the circumference in the meridional direction has a periodicity,
    wherein the cross-sectional shape of at least one groove along the circumference considered in the meridian section varies,
    wherein the course of at least one groove along the circumference is completely interrupted at least once,
    wherein adjacent ends of at least one groove are offset in the region of the interruption in the meridional direction,
    wherein the depth h of at least one groove continuously increases in the direction of the relative movement of the relevant blade end over at least a portion of its course,
    wherein at least one deflection means is provided within at least one groove, which is a local obstacle for an internal groove flow and is such that a change in direction of the flow is achieved, wherein the at least one deflection means is set back from the main flow path boundary, such that a free Edge of the deflection means reaches at most the straight-line connection of the groove opening points C and D tangent in a part of their course,
    wherein a nutinternes deflection means is provided, which has a curvature and / or profiling in the region of its free edge for better flow guidance.

LIST OF REFERENCE NUMBERS

1

casing

2

Ring channel / main flow path

3

Rotor drum (hub)

4

machine axis

5

Blade / blade row

6

Hub or housing assembly

7

Ring groove / groove (oriented upstream)

8th

Blade row with free end and running gap

9

upstream blade row (optional)

10

Slot / groove

11

Gap / running gap

12

slot opening

13

circumferential groove

Claims (9)

Turbomachine having a main flow path (2) bordered by a hub (3) and a housing (1), in which at least one row of blades (5) is arranged, wherein at least one blade row (5) has a gap between a blade end and a main flow path boundary (11) is provided, wherein the blade end and the Hauptströmungspfadberandung perform a rotating relative movement to each other and in the region of the gap (11) in the Hauptströmungspfadberandung at least one substantially extending in the circumferential direction of the machine groove (7) along at least a portion of the circumference is provided wherein the extent of the groove (7) in the circumferential direction is large compared to the extent of the groove (7) in the meridional flow direction, and wherein the cross-sectional area of the groove (7) in the meridian view of the fluid flow machine is substantially deviated from a parallelogram shape and is inclined upstream due to its contouring . characterized in that the center of gravity of the groove cross-sectional area is provided upstream of the center of the groove opening (12) on the main flow path. A turbomachine according to claim 1, characterized in that the position of the at least one groove (7) described by the distance VN between the blade leading edge corner A and the slot opening start point C is given by the condition -0.25 <VN / Lm <0.95 where Lm is the meridional chord length at the blade end at the nip (11), and / or that the position of the at least one groove (7) relative to the blade leading edge is set as follows: -0.15 <VN / Lm <0.35, and or that the position of the at least one groove (7) relative to the blade leading edge is set as follows: -0.15 <VN / Lm <0.15. Turbomachine according to one of claims 1 or 2, characterized in that the at least one groove (7) has a strongly upwardly inclined Form whose characteristics are defined in the plane defined by the axial direction x and the radial direction r meridian plane by a network of six auxiliary lines, wherein a.) all auxiliary lines run parallel or perpendicular to the reference direction AB along the blade end, b.) a line L1 runs parallel to AB through the slot opening end point D, c.) a line L2 runs parallel to L1 through the slot opening start point C, d.) a line L3 parallel to L1 runs tangentially along the groove contour so that it has at least one point G at a location at maximum groove penetration depth h with L3 in common, e.) a line L4 perpendicular to L1 runs tangentially along the groove contour, so that it has at least one point F at a location with maximum groove-upstream overhang m in common with L4, f.) A line L5 perpendicular to L1 runs tangentially along the groove contour, so that according to the invention it has at least one point E at a location with maximum groove downstream overhang n in common with L5. g.) a line L6 perpendicular to L1 passes through the groove opening start point C and divides the cross-sectional area of the groove into the surface AF located upstream of L6 and the surface AR located downstream of L6, h.) have the center of gravity S of the groove cross-sectional total area and the Nutöffnungsmittelpunkt M a distance d, i.) between the edge points C and D of the slot opening a slot opening width w is given, j.) an offset k is provided between the auxiliary lines L1 and L2, k.) the blade has at its end a meridional chord length Lm and wherein characteristics of the groove are defined in the following manner: w / Lm <0.2 and h / w <10 and d / w> 0.05 and m / w> 0.1 and AF / AR> 0.1 and amount of (k / w) <2. Turbomachine according to one of claims 1 to 3, characterized in that in the area of the surface AR in the section between the Nutöffnungsendpunkt D and the point G at maximum Nuteindringtiefe the inclination angle of the groove contour γ _R only values between 0 ° and 90 ° and preferably in the region of the surface AR in at least part of the portion between the groove opening end point D and the point G at maximum groove penetration depth, the groove contour is linear or concave (relative to the interior of the groove), and / or the inclination angle of the groove contour γ _R at the slot opening end D assumes values between 15 ° and 55 °. Turbomachine according to one of claims 1 to 4, characterized in that in the region of the surface AF in the section between the Nutöffnungsstartpunkt C and the point F at maximum Stromaufausdehnung the inclination angle of the groove contour γ _F only assumes values between 0 ° and 90 °, and preferably in Area of the area AF in at least a portion of the portion between the Nutöffnungsstartpunkt C and the point F at maximum Stromausausdehnung the groove contour is linear or concave (relative to the interior of the groove) is designed, and / or the inclination angle of the groove contour γ _F at Nutöffnungsstartpunkt C values between 15 ° and 55 °. Turbomachine according to one of claims 1 to 5, characterized in that together with the at least one groove (7) a Schaufelanstreifbelag is provided as Hauptströmungspfadberandung in the region of the running gap (11), wherein the Anstreifbelag only within a portion of the meridionalen extent of the Schaufellaufpfades or running gap (11) is provided, and the scuffing after upstream and / or downstream of a groove (7) is limited such that at least one of the blade edge points A and B are in a non-squish covered portion, and preferably the squeal at its transition to at least one groove (7) has an edge completely surrounded by the material of the component forming the main flow path boundary, and at least one point at which the blade end is directly opposite the material of the component surrounding the abradable coating, a recess is provided at the blade end, the locomotive al avoids scratching the blade end. Turbomachine according to one of claims 1 to 6, characterized in that the signature lines of at least one groove, ie the front line LF, the Nutöffnungsstartlinie LC and the Nutöffnungsendlinie LD, exactly in the circumferential direction along the main flow path boundary run, and / or at least one signature line at least one groove (front line LF, Nutöffnungsstartlinie LC, Nutöffnungsendlinie LD) has a circumferentially varying in the meridional direction, preferably the course of the at least one signature line of at least one groove (7) varying along the circumference in the meridional direction has a periodicity. Turbomachine according to one of claims 1 to 7, characterized in that the considered in meridian section cross-sectional shape of at least one groove (7) varies along the circumference and / or the course of at least one groove along the circumference is at least once completely interrupted, preferably the depth h at least one groove (7) continuously increases in the direction of the relative movement of the relevant blade end over at least a portion of its course, and / or adjacent ends of at least one groove (7) are offset in the meridional direction in the region of the interruption, wherein preferably the depth h is at least a groove (7) continuously increases in the direction of the relative movement of the relevant blade end at least over a portion of its course. Flow working machine according to one of claims 1 to 8, characterized in that within at least one groove (7) at least one deflection means is provided, which is a local obstacle for an intra-groove flow and is such that a change in direction of the flow is achieved, wherein the at least one deflection of the Hauptströmungspfadberandung is set back, such that a free edge of the deflection reaches tangentially at most the linear connection of the Nutöffnungspunkte C and D in a part of its course, preferably a Nutinternes deflection is provided, which in the region of its free edge to better flow guidance has a curvature and / or profiling.

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