EP2725194B1 - Turbine rotor blade of a gas turbine - Google Patents

Description

The invention relates to a turbine rotor blade of a gas turbine with a blade profile designed in the radial direction (based on an engine axis of the gas turbine) or in the longitudinal direction of the blade, and with a blade tip. In connection with the present invention, the blade tip is the radially outer end of the turbine rotor blade.

The invention further relates not only to rotor blades, but also to stator blades, the blade tip in stator blades being defined as the radially inner end of the blade.

It is known in the prior art that a leakage mass flow driven by the pressure difference from the blade pressure side to the blade suction side occurs at the radial gap between the rotor blades and a housing or between stator blades and a hub. Solutions have been proposed which reduce this leakage mass flow and / or reduce the negative influence of a vane tip vortex which forms on the turbine aerodynamics.

To improve the flow over the blade tips of the rotors, circumferential sealing edges (squealers) are mainly provided, but in some cases also overhangs on the blade tip (winglet designs). Squealer constructions ( US 2010/0098554 A1 ) cause only a slight improvement in aerodynamics. The winglet construction according to US 7,118,329 B2 has an overhang to the pressure side near the trailing edge of the blade and a circumferential sealing edge at the tip of the blade with an opening at the trailing edge of the blade. The construction according to US 6,142,739 has an overhang on the suction and pressure side, which is very small near the front edge of the blade and overhangs along the blade skeleton line to the rear edge of the blade. Furthermore, this construction has an opening of the blade tip cavity at the rear edge.

The solutions known from the prior art on the one hand bring only slight aerodynamic advantages, on the other hand the overhangs (winglets) are dimensioned in such a way that that they can be carried particularly poorly by the thin rear edge of the blade and impair the mechanical strength of the blade.

From the GB 1 491 556 is a rotor blade for turbomachinery previously known, which has a one-sided projection on the suction side of the blade tip. The protrusion is in the form of a cover plate (partial shroud), which is attached to the blade tip and, starting from the leading edge of the blade, immediately extends to a multiple of the blade thickness and maintains this large value of the overhang up to the blade rear edge. Such overhangs are critical with regard to the loads acting on the blade and do not lead to optimized flow conditions.

The EP 1 898 052 A2 describes a turbine blade which has an overhang on its suction side over part of its length.

The invention has for its object to provide a turbine rotor blade of the type mentioned which, with a simple structure and simple, inexpensive manufacturability, enables optimum flow around the blade tip from an aerodynamic and thermal point of view and has good component strength and a long service life.

According to the invention the object is achieved by the combination of features of claim 1, the subclaims show further advantageous embodiments of the invention.

It is thus provided according to the invention that the blade tip has an overhang (winglet) at least on its suction side, starting from a stagnation point on the blade leading edge to an intersection of the suction-side profile line of the blade with a trailing edge circle. The overhang points on The stagnation point and at the point of intersection with the trailing edge circle essentially has a value of zero and reaches its maximum value at approximately 40% of the running length of the suction-side profile line.
According to the invention, a flow-optimized construction which is advantageous with regard to the strength of the blade is thus created, in which the aerodynamic losses are minimized.

It is particularly favorable if the size of the suction-side overhang (vertical distance from the suction-side profile line) reaches approximately 45% of the diameter of the maximum circle T _max that can be written into the blade profile.

In a particularly favorable embodiment of the blade according to the invention, it is further provided that the blade tip also has an overhang (winglet) on its pressure side, starting from a stagnation point on the blade leading edge to an intersection of the pressure-side profile line of the blade with the trailing edge circle, which at the stagnation point and is essentially zero at the intersection and which has a maximum value at approximately a run length of between 20% and 60% of the total run length of the pressure-side profile line.

To improve the flow and to further reduce the leakage mass flow, it can furthermore be favorable that a circumferential sealing edge is formed on the radially outer edge region of the blade (in the case of a rotor blade) or on the radially inner edge region in the case of a stator blade. This can have a substantially rectangular cross section, for example, so that a depression / cavity is formed in the central region of the tip of the ice bucket.

The sealing edge can furthermore preferably have an area with a reduced height or an area with a height of zero, which is provided in the area of the suction-side overhang between a running length of the suction-side profile line of 10% to 30%. An opening is thus formed through which the boundary layer near the housing can flow to the blade tip.

It is particularly advantageous to dimension the height and the width of the sealing edge as a function of a blade tip gap. The radial height can be between half of the blade tip gap and three times the blade tip gap. With regard to the width of the sealing edge, this can be formed between the triple blade tip gap and the sixfold blade tip gap.

With regard to the height of the overhang (winglets) in the radial direction, it can be particularly favorable if this height is at most 10% of the radial length of the blade profile. A preferred value is 5%. This means that approximately 90% to 95% of the blade profile is unchanged and that only the outer 10 or 5% of the length of the blade profile is provided with the overhang or winglet according to the invention.

In order to further optimize the flow conditions, it can be advantageous to round off the transition from the blade profile to the overhang (winglet).

Furthermore, it can be advantageous to provide the edge region of the overhang (winglets) with an angle at the radial end. This angle is defined in a plane that is spanned by a radial vector from the sealing edge to the engine axis and a vector normal to the sealing edge. The angle then forms between a tangent to the outer sealing edge surface and the radial vector. It is Particularly favorable if the tangent on the pressure-side sealing edge of the blade is directed away from the blade at an angle between 10 ° and 50 ° and on the suction-side sealing edge at an angle of 10 ° to 50 ° with a barrel length of 0.1≤s≤0 , 3 is directed towards the blade and is designed with a barrel length between 0.4≤s≤1 at an angle between 10 ° and 50 ° away from the blade.

• Durch die relative schnelle Verkleinerung des großen saugseitigen Überhangs im Bereich (b) entsteht eine konkave Schaufelspitzenform. Das führt dazu, dass der Schaufelspitzenwirbel stromab einen immer größeren Abstand zur Schaufel gewinnt.
• Als Folge wird der Schaufelspitzenwirbel von der saugseitigen Schaufelumströmung entkoppelt und interagiert nicht oder nur sehr wenig mit dem sich in diesem Bereich entwickelnden Sekundärströmungswirbel. Diese Entkopplung trägt maßgeblich zur Wirkungsgradverbesserung der Schaufelspitzenströmung durch das Winglet bei.
• Der Überhang des Winglets reduziert den treibenden Druckgradienten zwischen Druckseite und Saugseite und verringert damit den Leckagemassenstrom.
• Die Öffnung der umlaufenden Dichtkante des Winglets sorgt für eine Einströmung von relativ kalter gehäusenaher Luft in die Kavität des Winglets. Die Trajektorie dieser Zuströmung (Stromlinienkrümmung) bewirkt einen Druckgradienten in Richtung Druckseite der Schaufel. Hierdurch wird eine weitere Reduktion des Leckagemassenstromes erzielt. Weiterhin verringert die aufströmende relativ kalte Luft die Kühlungsanforderungen für das Winglet.
• Die Form (Tangentenwinkel) der umlaufenden bzw. unterbrochenen Dichtkante ist in Abhängigkeit der Profillauflänge so gestaltet, dass an gewünschten Positionen Strömungsablösungen hervorgerufen werden (z.B. Druckseite) und an anderen Positionen (z.B. Saugseite) Strömungsablösungen vermieden werden.

The winglet construction according to the invention has the property of improving the overflow of the turbine blade tips in such a way that the leakage mass flow through the blade tip is reduced (efficiency improvement in the rotor) and at the same time the outflow in the region of the rotor blade tip is evened out with regard to the outflow angle (efficiency improvement in the downstream blade rows). These advantages are achieved through the following fluid mechanical effects:

• The relatively quick reduction of the large suction-side overhang in area (b) creates a concave blade tip shape. As a result, the blade tip vortex gets an ever greater distance from the blade downstream.
• As a result, the blade tip vortex is decoupled from the suction flow around the blade and does not interact or only interacts very little with the secondary flow vortex developing in this area. This decoupling contributes significantly to the efficiency improvement of the blade tip flow through the winglet.
• The overhang of the winglet reduces the driving pressure gradient between the pressure side and the suction side and thus reduces the leakage mass flow.
• The opening of the circumferential sealing edge of the winglet ensures that relatively cold air near the housing flows into the winglet's cavity. The trajectory of this inflow (streamline curvature) causes a pressure gradient in the direction of the pressure side of the blade. This results in a further reduction in the leakage mass flow. Furthermore, the relatively cold air flowing in reduces the cooling requirements for the winglet.
• The shape (tangent angle) of the circumferential or interrupted sealing edge is designed depending on the length of the profile so that flow separations are caused at desired positions (e.g. pressure side) and flow separations are avoided at other positions (eg suction side).

Fig. 1

eine schematische Darstellung eines Gasturbinentriebwerks gemäß der vorliegenden Erfindung,

Fig. 2

eine vereinfachte Draufsicht auf den Endbereich der erfindungsgemäßen Schaufel,

Fig. 3

eine Ansicht, analog Fig. 2, mit Angabe der Schnittlinien der Fig. 4 bis 6,

Fig. 4 bis 6

Teil-Schnitte gemäß den Schnittlinien in Fig. 3,

Fig. 7

eine Darstellung, ähnlich Fig. 5, mit Angabe der Definitionen zur Bemessung des Schaufelendbereichs,

Fig.8, 9

stirnseitige Ansichten, analog den Fig. 2 und 3, zur Darstellung des erfindungsgemäßen Überhangs,

Fig. 10, 11

Dickenverteilungen des saugseitigen und druckseitigen Überhangs bezogen auf die Lauflänge der saugseitigen bzw. druckseitigen Profillinie,

Fig. 12

eine perspektivische stirnseitige Ansicht, analog den Fig. 2 und 3, mit Darstellung der Dichtkante,

Fig. 13

eine Draufsicht auf die Darstellung gemäß Fig. 12 mit Strömungslinien,

Fig. 14

eine Schnittansicht, analog den Fig. 4 bis 6, mit Darstellung des Strömungsverlaufs, und

Fig. 15

eine Draufsicht zur Verdeutlichung des in Fig. 14 gezeigten Strömungsverlaufs.

The invention is described below using an exemplary embodiment in conjunction with the drawing. It shows:

Fig. 1

1 shows a schematic illustration of a gas turbine engine according to the present invention,

Fig. 2

a simplified plan view of the end region of the blade according to the invention,

Fig. 3

a view, analog Fig. 2 , with specification of the cutting lines of the 4 to 6 .

4 to 6

Partial cuts according to the cutting lines in Fig. 3 .

Fig. 7

an illustration, similar Fig. 5 , with definition of the dimensions for the blade end area,

Fig. 8, 9

frontal views, analogous to the Fig. 2 and 3 , to represent the overhang according to the invention,

10, 11

Thickness distributions of the suction-side and pressure-side overhang related to the running length of the suction-side and pressure-side profile line,

Fig. 12

a perspective front view, similar to Fig. 2 and 3 , with representation of the sealing edge,

Fig. 13

a plan view of the representation according to Fig. 12 with flow lines,

Fig. 14

a sectional view, analogous to 4 to 6 , with representation of the flow, and

Fig. 15

a plan view to illustrate the in Fig. 14 flow pattern shown.

The gas turbine engine 10 according to Fig. 1 Fig. 4 is a generally illustrated example of a turbomachine to which the invention can be applied. The engine 10 is designed in a conventional manner and comprises an air inlet 11, a fan 12 rotating in a housing, a medium-pressure compressor 13, a high-pressure compressor 14, a combustion chamber 15, a combustion chamber 15, a high-pressure turbine 16, a medium-pressure turbine 17 and a low-pressure turbine 18 as well as one in the flow direction Exhaust nozzle 19, which are all arranged around a central engine axis 1.

The intermediate pressure compressor 13 and the high pressure compressor 14 each comprise a plurality of stages, each of which has a circumferential arrangement of fixed stationary guide vanes 20, which are generally referred to as stator vanes, and which extend radially inward from the engine housing 21 in an annular flow channel through the compressors 13, 14 protrude. The compressors also have an arrangement of compressor blades 22 which project radially outward from a rotatable drum or disk 26 which is coupled to hubs 27 of the high-pressure turbine 16 and the medium-pressure turbine 17.

Turbine sections 16, 17, 18 have similar stages, including an array of fixed vanes 23 projecting radially inward from housing 21 into the annular flow channel through turbines 16, 17, 18 and a subsequent array of turbine rotor blades 24 which protrude outward from a rotatable hub 27. The compressor drum or compressor disk 26 and the blades 22 arranged thereon as well as the turbine rotor hub 27 and the turbine rotor blades 24 arranged thereon rotate in operation about the engine axis 1.

The Fig. 2 shows an end view of an embodiment of a turbine rotor blade 24 according to the invention. It is understood that the end Surface is not flat, but part of a cylinder jacket around the engine axis 1. In order to simplify the illustration, the end face is each formed flat in the following figures.

The Fig. 2 thus shows a shape of the rotor blade tip according to the invention in plan view. A feature of the invention is the special shape of the suction-side overhang 30. The shape of the suction-side overhang 30 according to the invention is by means of the Fig. 8 and 10 described in more detail. Two reference points, namely the stagnation point on the blade leading edge (under 2D flow) LE and the intersection of the suction-side profile line with the trailing edge circle TE are used to describe the suction-side winglet overhang. The dimensionless run length s is defined between these two reference points along the suction-side profile line, so that s (LE) = 0 and s (TE) = 1. Along s, the winglet overhang T _w (s) is defined as a thickness distribution, ie as a perpendicular distance to the suction-side blade profile line. The thickness distribution is made dimensionless with the maximum profile thickness T _{max of} the blade tip (diameter of the largest circle 31 that can be written into the blade profile).

In order to use the aerodynamic effects of the suction-side overhang 30, the thickness distribution is in Fig. 10 particularly advantageous. At the two reference points LE and TE, the thickness distribution is close to 0 (there is no significant overhang 30). Starting from the point LE, the overhang 30 initially only increases very slightly along s. From approx. S = 0.1 there is a rapid increase in the thickness distribution, area (a), up to the maximum T _{w, max} , which at approx. 40% of the barrel length s = 0.4, or approximately in the area of the narrowest cross-section (throat) the blade passage between adjacent blades is reached. Between approx. 0.5 <= s <= 0.7, area (b), the thickness distribution decreases rapidly to approx. 20% T _{w, max} and finally slowly decreases to 0%, s (1), area ( c). Furthermore, in Fig. 10 two further thickness distributions (dashed lines shown), which thus delimit an area for the particularly advantageous design of the suction-side overhang 30.

In the 8 and 9 a blade profile 29 is shown as a dashed line, this line corresponds to the blade profile under the overhang (winglet) 30 at 90% of the blade height. Line 38 shows the contour of the suction-side overhang ( Fig. 8 ) while the line 39 the contour of the overhang on the pressure side ( Fig. 9 ) shows. The circle, which can be inscribed in the region of the maximum thickness of the cross section of the blade profile 29, is drawn in with the reference symbol 31. The reference numeral 32 shows the trailing edge circle.

As in the Fig. 2 and 3 shown, the edge of the overhang 30 is designed in the form of a sealing edge 33, which is carried out essentially all around. As will be described below, it has an opening 34 ( 12 and 13 ). While in Fig. 8 The overhang on the suction side is shown and explained in detail Fig. 9 the overhang on the pressure side with its contour 39.

The 4 to 7 each show sectional views along the in Fig. 3 shown cutting lines.

The thickness curves of the overhangs on the suction side and the pressure side are in the 10 and 11 shown. The course is in each case plotted over a dimensionless run length s, which extends from the stagnation point on the blade leading edge LE along the suction or pressure-side profile line to the point of intersection of the profile line with the trailing edge circle TE. The size of the overhang T _w (s) is standardized to the diameter of the maximum circle T _max that can be written into the blade profile. The result is at which points the maximum values are provided particularly cheaply. The dashed lines in the 10 and 11 show a preferred design range, while the solid line represents an optimized solution.

• Einen relativ kleinen, aber signifikanten druckseitigen Überhang T_w(s), der, wie in Fig. 9 und 11 gezeigt, zwischen 0≤s≤0,2 sehr klein ist, von s=0,2 bis s=0,6 bis auf sein Maximum von 15% T_max anwächst und schließlich von s=0,6 bis zur Schaufelhinterkante abfällt, sodass der druckseitige Überhang bei s=1 tangential an den Hinterkantenkreis übergeht. Eine günstige Gestaltung des druckseitigen Überhanges kann mittels der gestrichelten Kurven in Fig. 11 eingegrenzt werden.
• Eine Öffnung, zumindest aber eine Verringerung der Höhe d der umlaufenden Dichtkante im vorderen Bereich des saugseitigen Überhangs zwischen ca. s=0,1 und s=0,3, wie in Fig. 12 und 13 gezeigt.
• Eine mittels des Rotorschaufelspitzenspaltes (nominal im Normalbetrieb) t definierte Höhe d der umlaufenden bzw. unterbrochenen Dichtkante auf dem Winglet von ca. 0,5t≤d≤3t (siehe Fig. 7).
• Eine mittels des Rotorschaufelspitzenspaltes t definierte Breite b der umlaufenden bzw. unterbrochenen Dichtkante auf dem Winglet von ca. 3t≤b≤6t (siehe Fig. 7).
• Eine Höhe h des Winglets von nicht mehr als 10 % der mittleren Höhe des Rotorschaufelprofiles. In besonders günstiger Ausführung sollte h∼5% der mittleren Höhe des Rotorschaufelprofiles betragen (siehe Fig. 7). Dabei ist h als der radiale Abstand der Wingletspitze von dem radialen Schaufelprofilschnitt anzusehen, bei dem die Aufweitung des Schaufelprofils in das Winglet deutlich beginnt.
• Einen stetigen, mit angemessenen Radien R (bzw. geeigneten Kurvenformen) abgerundeten, sanften Übergang zwischen dem Wingletüberhang und dem Schaufelprofil (siehe Fig. 7).
• Einen von der Profillauflänge s abhängigen, beispielhaft mittels der Schaufelschnitte A:A, B:B und C:C in Fig. 7 definierten Winkel β zwischen der Tangente an der äußeren Dichtkante 35 und dem Radialenvektor 36, sodass die Tangente an der Druckseite stets von der Schaufel mit einem Winkel zwischen 10°≤β_DS≤50° weg zeigt und die Tangente an der Saugseite zwischen 0,1≤s≤0,3 zu der Schaufel mit einem Winkel zwischen 10°≤β_SS≤50° hin zeigt, jedoch zwischen 0,4≤s≤1 stets mit einem Winkel von 10°≤β_SS≤50° von der Schaufel weg zeigt.

As shown in the figures, the rotor blade tip has the following preferred design properties in order to minimize the effect of the rotor tip gap leakage flow on the turbine efficiency:

• A relatively small but significant overhang T _w (s) on the pressure side, which, as in Fig. 9 and 11 shown, is very small between 0≤s≤0.2, increases from s = 0.2 to s = 0.6 to its maximum of 15% T _max and finally falls from s = 0.6 to the trailing edge of the blade, so that the overhang on the pressure side at s = 1 tangential passes to the trailing edge circle. A favorable design of the overhang on the pressure side can be shown by means of the dashed curves in Fig. 11 be narrowed down.
• An opening, or at least a reduction in the height d of the circumferential sealing edge in the front region of the suction-side overhang between approximately s = 0.1 and s = 0.3, as in 12 and 13 shown.
• A height d of the circumferential or interrupted sealing edge on the winglet defined by means of the rotor blade tip gap (nominally in normal operation) t of approx. 0.5t≤d≤3t (see Fig. 7 ).
• A width b of the circumferential or interrupted sealing edge on the winglet defined by means of the rotor blade tip gap t of approx. 3t≤b≤6t (see Fig. 7 ).
• A height h of the winglet of no more than 10% of the average height of the rotor blade profile. In a particularly favorable version, h∼5% of the average height of the rotor blade profile should be (see Fig. 7 ). Here, h is to be regarded as the radial distance of the winglet tip from the radial blade profile section, at which the expansion of the blade profile into the winglet clearly begins.
• A smooth, smooth transition between the winglet overhang and the blade profile, rounded with appropriate radii R (or suitable curve shapes) (see Fig. 7 ).
• One dependent on the profile run length s, for example by means of the blade cuts A: A, B: B and C: C in Fig. 7 Defined angle β between the tangent to the outer sealing edge 35 and the radial vector 36, so that the tangent on the pressure side always points away from the blade with an angle between 10 ° β β _DS 50 50 ° and the tangent on the suction side between 0.1 ≤s≤0.3 towards the blade with an angle between 10 ° ≤β _SS ≤50 °, but always between 0.4≤s≤1 with an angle of 10 ° ≤β _SS ≤50 ° away from the blade shows.

To illustrate the above explanations, the 4 to 6 each sectional views according to Fig. 3 , from which the preferred configurations result. In particular, the 4 to 6 the respective angle β between the tangent 35 and the radial vector 36. Die Fig. 7 clarifies the dimensional definitions again and additionally schematically represents the housing 40 and the blade tip gap 37.

From the 12 to 15 the flow conditions are shown again. The Fig. 13 shows in particular an inflow through the opening 34 and a flow through the blade tip gap 37 14 and 15 for clarification an example of a vane tip vortex 41 that forms and a secondary flow vortex 42.

LIST OF REFERENCE NUMBERS

1

Engine axis

10

Gas turbine engine / core engine

11

air intake

12

fan

13

Medium pressure compressor (compressor)

14

High pressure compressor

15

combustors

16

High-pressure turbine

17

Intermediate pressure turbine

18

Low-pressure turbine

19

exhaust nozzle

20

vanes

21

Engine casing

22

Compressor blades

23

vanes

24

Turbine rotor blades

26

Compressor drum or disk

27

Turbinenrotornabe

28

outlet cone

29

Blade profile (under the winglet at approx. 90% blade height)

30

Overhang / winglet

31

Circle (with maximum diameter that can be written into the blade profile)

32

Trailing edge circuit

33

sealing edge

34

Opening the sealing edge

35

Tangent to the sealing edge

36

Radial vector on the sealing edge

37

Blade tip clearance

38

Contour of the overhang on the suction side

39

Contour of the overhang on the pressure side

40

Turbine rotor housing end wall

41

Blade tip clearance vortex

42

Secondary flow vortices

DS

pressure side

SS

suction

LE

Stagnation point on the front edge of the bucket

TE

Intersection of the profile line on the suction or pressure side with the trailing edge circle

b

Width of the sealing edge

d

Height of the sealing edge

H

Overhang height (winglet)

R

Rounding radii between overhang (winglet) and blade profile

s

yardage

t

Height of the blade tip gap

T _max

maximum blade profile thickness

T _w

Overhang (winglet) size

T _{w, max}

maximum overhang (winglet) size

Claims (10)

1. Turbine rotor blade of a gas turbine, having a blade tip, wherein the blade tip has, at least on its suction side (SS), an overhang (30) proceeding from a stagnation point (LE) at the blade front edge as far as a point of intersection (TE_SS) of the suction-side profile line of the blade (24) with a rear-edge circle (32), which overhang substantially amounts to zero at the blade front edge and at the blade rear edge, characterized in that the overhang (30) attains its maximum value (T_w,max) substantially at a path length s=0.4 and has a reduction in the overhang from substantially 0.8T_w,max to 0.2T_w,max over a path length range of 0.5≤s≤0.7.
2. Turbine rotor blade according to Claim 1, characterized in that the blade tip has, on its pressure side (DS), an overhang (30) proceeding from a stagnation point (LE) at the blade front edge as far as a point of intersection (TE_DS) of the pressure-side profile line of the blade (24) with a rear-edge circle (32), which overhang substantially amounts to zero at the stagnation point (LE) and at the point of intersection (TE_DS) and has a maximum value approximately at a path length (s) of 20% to 60% of the path length (s) of the pressure-side overhang (30).
3. Turbine rotor blade according to either of Claims 1 and 2, characterized in that a peripheral sealing edge (33) is formed on the radially outer boundary region of the blade (24).
4. Turbine rotor blade according to Claim 3, characterized in that, in the region of the suction-side overhang (30), the sealing edge (33) has, between a path length (s) of 10% and of 30%, a height (d) which is reduced or is reduced to a value of zero.
5. Turbine rotor blade according to Claim 4, characterized in that an opening (34) is formed by the reduced height (d) of the sealing edge (33) and extends between 10% and 30% of the path length (s) of the sealing edge (33).
6. Turbine rotor blade according to one of Claims 3 to 5, characterized in that the sealing edge (33) has a radial height (d) with 0.5t≤d≤3t, where t is the blade tip gap (37) provided during operation, and/or in that the sealing edge (33) has a width (b) with 3t≤b≤6t.
7. Turbine rotor blade according to one of Claims 1 to 6, characterized in that the height (h) of the overhang (30) is at most 10%, preferably 5%, of the radial length of the blade profile (29).
8. Turbine rotor blade according to one of Claims 1 to 7, characterized in that the transition from the blade profile (29)to the overhang (30) is of rounded form.
9. Turbine rotor blade according to one of Claims 1 to 8, characterized in that an angle (β) between a tangent (35) to the outer edge of the overhang (30) and a vector (36) extending in a radial direction with respect to an engine axis (1) is formed such that the tangent (35), on the pressure side (DS), is formed so as to be directed away from the blade (24) at an angle (β_DS) with 10°≤β_DS≤50°, and on the suction side (SS), is formed so as to be directed towards the blade (24) at an angle (β_SS) with 10°≤ β_SS≤50° over a range 0.1≤s≤0.3 and so as to be directed away from the blade (24) at an angle with 10°≤β_SS≤50° over a range 0.4≤s≤1.
10. Arrangement having at least one turbine rotor blade according to one of Claims 1 to 9, characterized in that the maximum value of the suction-side overhang (30) is formed substantially in the region of a narrowest cross section of a blade passage.

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