RU155492U1 - GAS-TURBINE ENGINE LOW PRESSURE ROTOR WHEEL BLADE - Google Patents

Abstract

1. The blade of a disk having grooves of the impeller of the first stage of the rotor of a low pressure compressor (KND) of a gas turbine engine containing a flow part having a low pressure turbine, a high pressure turbine and a power turbine, characterized in that it contains a feather that is made with an axis, convex -concave profile formed by a concave trough and a convex back, conjugated in the direction of flow of the working fluid by the input and output edges, and with a spiral twist of the profile along the height of the pen, as well as a shank with a longitudinal axis, designed to be installed in any of the grooves of the disk of the first stage impeller, ensuring the angle α of setting the profile of the pen to the axis of the rotor in the projection onto the conditional axial plane of the rotor, normal to the axis of the pen of the blade, with the value α = (17 ÷ 27 in the root section of the pen) ) °, a in the peripheral section of the pen, the value α = (54 ÷ 64) °, and the longitudinal axis of the profile of the pen, which coincides with the axis of twist of the profile, is taken as the axis of the pen’s blade, and the feather of the blade is made with input and output edges diverging to the peripheral end with uve gradient of the chord G, G = (LL) / H = (7.2 ÷ 10.7) · 10 [m / m], where L is the length of the peripheral chord connecting the input and output edges of the feather blade in a conditional plane parallel to the axial plane rotor; L is the length of the root chord connecting the input and output edges of the feather blade in a conventional plane parallel to the axial plane of the rotor; H is the average feather height of the scapula; in addition, the feather of the blade is made variable in width and height of the feather thickness, defined in cross section as the difference between the heights of the back and trough relative to the conditional chord connecting the edges of the pen

Description

The utility model relates to the field of aircraft engine manufacturing, namely, to low-pressure axial compressors of aircraft gas turbine engines.

Known profiled compressor blade for the impeller disk having axial, tangential and radial orthogonal axes, containing high and low pressure sides, extending in the radial direction from the shank to the apex and in the axial direction between the front and rear edges, cross sections having corresponding chords and bending lines extending between the leading and trailing edges, and centers of gravity aligned along a pivot axis having a double bend. The low pressure side is curved along the trailing edge near the liner to reduce the separation of the flow on it (RU 2000130594 A, publ. 01.27.2003).

Known compressor blades, including a feather and a shank. The shank of the blade is located horizontally, and the feather is connected to the shank through an intermediate element - the leg. Between the leg and the feather there is a shelf forming the engine flow part (NN Sirotin, AS Novikov, AG Paykin, AN Sirotin. Fundamentals of designing the production and operation of aircraft gas turbine engines and power plants in the CALS system technologies. Book 1. Moscow. Science 2011. p. 257-263).

The disadvantages of the known solutions include the uncertainty of achieving effective interaction of the blades with the flow of the working fluid due to the lack of specification of the ranges of geometric and aerodynamic parameters of the spatial configuration of the pen and the angular installation of the blades in the impeller of the first stage of the rotor, as well as the difficulty of obtaining a compromise combination of increased values of efficiency, gas-dynamic stability (GDU ) compressor and, as a consequence, the difficulty of providing optimal dynamic strength and ennogo blade resource.

The objective of the utility model is to develop the blades of the impeller of the first stage of the rotor of the low pressure compressor (KND) of the gas turbine engine (GTE) with improved structural and aerodynamic parameters of the spatial configuration and the stiffness of the feather blade, providing the possibility of increasing the flow rate of the compressible working fluid - air in the first stage and supply air flow to the subsequent stages of the low pressure switch at all engine operating modes, as well as an increase in gas-dynamic stability and resource without increasing m the material capacity of the scapula.

The problem is solved in that a blade of a low-pressure compressor of a gas turbine engine having a disk with grooves of the impeller of the first stage of the rotor of the compressor, comprising a flow part that is bounded along the peripheral contour by an engine casing having a low pressure turbine (HP), high pressure turbine (HPT) and power a turbine (ST), according to a utility model, contains a feather, which is made with an axis, a convex-concave profile formed by a concave trough and a convex back, conjugate in the direction of flow of the working la inlet and outlet edges, and a helical twist of the profile height of the pen, as well as a shank with a longitudinal axis intended to be installed in any of the disk grooves of the impeller of the first stage to ensure the angle α _{to the} profile settings of the pen to the rotor axis in a projection on a notional centerline the rotor plane normal to the axis of the feather of the blade, with α _k = (17 ÷ 27) ° in the root section of the feather, and the value α _p = (54 ÷ 64) ° in the peripheral section of the feather, and the longitudinal axis is taken as the axis of the feather blade pen profile, coinciding with the axis of twist n profile, and the feather of the blade is made with input and output edges diverging to the peripheral end with a gradient of increase in the chord G _yx ,

G _yx = (L _p.x.- L _k.h. ) / H _cp = (7.2 ÷ 10.7) · 10 ^-2 [m / m],

where L _p.x - the length of the peripheral chord connecting the input and output edges of the feather blades in a conventional plane parallel to the axial plane of the rotor; L _c.h. - the length of the root chord connecting the input and output edges of the feather blades in a conventional plane parallel to the axial plane of the rotor; N _cf - the average height of the feather blades; in addition, the feather of the blade is made variable in width and height of the feather with a thickness defined in cross section as the difference between the heights of the back and trough relative to the conditional chord connecting the edges of the feather of the blade, while the maximum thickness of the profile of the feather of the blade is made the largest in the root section and decreasing in height of the feather to peripheral end with a gradient G _{of standard fuel} equal to

G _yx = (C _to -C _p ) / N _cf = (1.25 ÷ 1.53) · 10 ^-2 [m / m], where

where C _to - the maximum thickness of the root section of the profile of the pen blade; With _p - the maximum thickness of the peripheral section of the profile of the pen blade; N _cf - the average height of the feather blades.

In this case, the blade can be made with the angle of the profile of the pen relative to the axis of the rotor, increasing in height of the blade with a radial distance from the axis of the rotor with a gradient of G _u.p. changing the angle of installation of the profile, which has a projection on the conditional axial plane of the rotor with values in the range

G _U.P. = (α _p -α _k ) / N _sr = (124.0 ÷ 186.8) [deg / m],

where α _to is the projection of the angle of the profile of the pen in the root section of the blade relative to the axis of the rotor on the conditional axial plane of the rotor, normal to the axis of the pen blade; α _p - the projection angle of the profile of the pen in the peripheral section of the blade relative to the axis of the rotor on the conditional axial plane of the rotor, normal to the axis of the pen blade; N _cf - the average height of the feather blades.

The blade can be provided on both sides of the pen with an anti-vibration shelf located in the region of one third of the height of the feather from the peripheral end of the blade feather, and each end of the specified shelf is made with the possibility of mutual support on the similar end of the adjacent blade of the impeller facing it.

The blade feather can be made with a convex-concave profile with a concave trough facing concavity in the direction of rotation of the rotor counterclockwise (view along the np - direction of flight) and with a convex back of the feather facing in convexity towards the side of rotation of the rotor and in the direction of rotation clockwise, while the chord connecting the input and output edges of the pen in the root zone forms, with the rotor axis, an angle α _{to the} installation of the profile of the pen of at least the angle α _{0 of the} installation of the shank of the blade in the projection onto the said conventional plane.

The blade feather can be made convex-concave with a concave trough facing concave in the direction of rotation of the rotor in a clockwise direction (view in n.p.) and with a convex back of the feather facing in convexity in the direction of rotation of the rotor and counterclockwise rotation direction (view by n.p.).

The peripheral end face of the blade pen is beveled with a repetition of the curvature of the inner surface of the engine duct in the zone of the first stage of the low pressure valve with a decrease in the radius in the direction of flow of the working fluid with a height sufficient for unhindered rotation of the blade of the impeller in the rotor of the low pressure sensor.

The technical result achieved by the given set of essential features of the impeller blade of the first stage of the rotor KND GTE consists in increasing the efficiency and expanding the range of compressor gas-dynamic stability modes by 2.2% with a 2-fold increase in the resource of the blade.

The essence of the utility model is illustrated by drawings, where:

in FIG. 1 shows a blade of the impeller of the first stage, side view;

in FIG. 2 - the blade of the impeller of the first stage, top view;

in FIG. 3 - feather blades of the impeller of the first stage, a cross section;

in FIG. 4 - a fragment of the disk of the impeller of the first stage with grooves for installing the shanks of the blades, frontal projection.

The gas turbine engine includes a low pressure compressor, a low pressure turbine, a high pressure compressor, a high pressure turbine and a power turbine. The blade of the impeller of the first stage of the rotor of the low-pressure compressor of the gas turbine engine, containing the flow part, limited by the peripheral contour of the engine housing, contains feather 1 and shank 2. Feather 1 of the blade is made with an axis, a convex-concave profile formed by a concave trough 3 and a convex back 4, conjugated in the direction of flow of the working fluid by the input and output edges 5 and 6, respectively, and with a spiral twist of the profile along the height of the pen 1. The shank 2 is made with a longitudinal axis and is designed to be installed in any of the grooves 7 the disk 8 of the impeller of the first stage with the angle α _to set the profile of the pen 1 to the axis of the rotor in the projection on the conditional axial plane of the rotor normal to the axis of the pen 1 of the blade, with a root cross section of pen 1 value α _to = (17 ÷ 27) °, and in the peripheral section of pen 1, the value of α _p = (54 ± 64) °. As the axis of the pen 1 of the blade adopted the longitudinal axis of the profile of the pen, coinciding with the axis of twist of the profile. As the axis of the rotor adopted the axis of rotation of the rotor.

The feather 1 of the blade is made variable in width and height of the feather thickness, defined in cross section as the difference between the heights of the back 4 and trough 3 relative to the chord 9 connecting the input and output edges 5 and 6 of the feather 1 of the blade.

The maximum thickness of the profile of the pen 1 of the scapula is made the largest in the root section and decreasing in height of the pen 1 to the peripheral end face 10 with a gradient of G _weight equal to

G _ut = (C _to -C _p ) / N _cf = (1.25 ÷ 1.53) · 10 ^-2 [m / m],

where C _to - the maximum thickness of the root section of the profile of the pen 1 of the scapula; With _p - the maximum thickness of the peripheral section of the profile of the pen 1 of the scapula; H _cf - the average height of the pen 1 scapula.

The blade is made with the angle of installation of the profile of the pen 1 relative to the axis of the rotor, increasing along the height of the blade with a radial distance from the axis of the rotor with a gradient of G _у. changing the angle α _{to the} installation profile, which has a projection on the conditional axial plane of the rotor with values in the range

G _U.P. = (α _p -α _k ) / N _sr = (124.0 ÷ 186.8) [deg / m],

where α _to is the projection of the installation angle of the profile of the pen 1 in the root section of the blade relative to the axis of the rotor on the conditional axial plane of the rotor normal to the axis of the blade; α _p - the projection angle of the profile of the pen 1 in the peripheral section of the blade relative to the axis of the rotor on the conditional axial plane of the rotor normal to the axis of the blade; H _cf - the average height of the pen 1 scapula.

The feather 1 of the blade is made with the input and output edges 5 and 6, respectively, diverging to the peripheral end face 10 with a gradient of increasing the chord G _yx ,

G _yx = (L _p.h. -L _c.x. ) / H _cp = (7.2 ÷ 10.7) · 10 ^-2 [m / m],

where L _p.x - the length of the peripheral chord connecting the input and output edges 5 and 6 of the pen 1 of the blade in a conventional plane parallel to the axial plane of the rotor; L _c.h. - the length of the root chord connecting the input and output edges 5 and 6 of the pen 1 of the blade in a conditional plane parallel to the axial plane of the rotor; H _cf - the average height of the pen 1 scapula.

The blade of the impeller of the first stage of the rotor is equipped on both sides of the pen 1 with an anti-vibration shelf 11 located in the area of one third of the height of the pen 1 from the peripheral end 10 of the pen 1 of the blade. Each end 12 of the specified shelf 11 is made with the possibility of mutual support on facing the same end face of the adjacent vanes of the impeller.

The feather 1 of the blade is made convex-concave profile. The concave surface of the pen profile in the form of a trough 3 is made by facing concavity in the direction of rotation of the rotor counterclockwise (view in np - direction of flight). The convex surface of the profile of the pen 1, forming the back 4 of the pen, is made convex to the side against the rotation of the rotor and in the direction of rotation of the clockwise direction (view on n.p.). The chord 9, connecting the input and output edges 5 and 6 of the pen 1 in the root zone 13, forms an angle α _{to the} installation of the profile of the pen 1 with the axis of the rotor in the projection onto the conditional plane of at least angle α _{0 of the} installation of the shank 2 of the blade.

Variant feather 1 of the blade is made of a convex-concave profile with a concave surface - a trough 3, facing concavity in the direction of rotation of the rotor clockwise (view in n.p.) and with a convex surface forming the back 4 of feather 1, facing convex in the direction of rotation rotor and counterclockwise rotation direction (view on n.p.).

The peripheral end face 10 of the pen 1 of the blade is made beveled with a repetition of the curvature of the inner surface of the engine duct in the zone of the first stage of the low pressure valve with a decrease in the radius in the direction of flow of the working fluid with a height sufficient for the smooth rotation of the blade of the impeller in the rotor of the low pressure sensor.

The blade of the impeller of the first stage of the rotor KND GTD is stage-by-stage made from the bar of an aircraft alloy. At the first stage, a fragment of the rod of the required length is cut, from which the blade blank with local thickenings in the areas of the shank 2 and the anti-vibration shelf 11 is cut by electric upsetting. In the next step, the blank is subjected to general heating in an electric furnace to the state of thermoplasticity and hot forging is performed, using a stamp consisting of two reciprocal profiled half-matrices. The working surface of one of the die semi-matrices includes a section whose shape is made of the mating spatial surface of the back 4 of the pen 1 of the blade. The working surface of the other die half-matrix includes a section whose shape is made of the mating spatial surface of the trough 3 of the pen 1 of the scapula. After that, the blade is subjected to mechanical processing, including grinding the flap milling, pulling the shank 2.

The refinement of the streamlined surfaces of the profiles of the pen 1 and the anti-vibration shelf 11 is performed by milling and subsequent polishing. The contact ends 12 of the anti-vibration shelf 11 are strengthened by applying a high-strength layer to them.

The blade made in this way consists of a single pen 1 with a shank 2 and an anti-vibration shelf 11, made as a segment of the assembled ring of the blade ring of the impeller of the first stage of the low pressure rotor of the gas turbine engine.

The profile of the pen 1 of the scapula has the following geometric parameters:

- in the root section, the profile of the feather blade is made with a maximum profile thickness C _max = 5.59 mm; pen chord length - 61.5 mm; the angle α _{to the} installation of the profile of the pen 1 to the axis of rotation of the rotor in the projection onto the axial plane of the latter, normal to the axis of the pen blade, is 22 °;

- in the peripheral section, the profile of the blade feather is made with a maximum profile thickness C _max = 2.08 mm; feather chord length adopted 82 mm; the angle α _{to the} installation of the profile of the pen to the axis of rotation of the rotor in the projection onto the axial plane of the latter, normal to the axis of the pen blade, is 60 °;

- the average height H _cf the pen profile is 245 mm.

The anti-vibration shelf 11 of the blade is made with a maximum thickness of 5 mm and is placed on the average radius from the axis of rotation of the rotor, taken 388 mm, with contact surfaces made at an angle of 25 ° to the axis of rotation of the rotor in the projection on the axial plane of the latter, normal to the axis of the blade blade.

The blade is made for fixing on the disk of the impeller of the rotor shaft by installing the shank 2 in the groove 7 of the rim of the disk 8.

When the compressor is operating, each blade of the impeller of the first stage of the KND rotor interacts with the working fluid, transferring the kinetic and potential energy to the latter. The result is a flow of a compressible working fluid directed towards the exit from the impeller rim of the impeller, which flows from the interscapular channels of the impeller rim of the rotor impeller to the blades and into the interscapular channels of the stator guide apparatus of the first stage. After alignment in the guiding apparatus, the flow enters the subsequent stages of the low pressure switch.

In the process of implementing the design of the impeller blade of the first stage of the KND rotor developed in a utility model, the technical result is achieved only when the blade is installed in the impeller with the profile of the pen 1 in the root section of the blade at an angle α _to the axis of the rotor in the projection onto the conditional axial plane of the rotor, normal 1 to the pen axis, in said angular range of values of α _k = (17 ÷ 27) °, combined with the simultaneous satisfaction consistent matching conditions found in a utility model geometric and aerodynamic their spatial configuration parameters and their gradients change the height of the blade. When assigning the angle α _to the root section of the blade, taken from the interval of values α _to = (17 ÷ 27) °, found in the utility model taking into account the installation angles of the pen profile of the subsequent stages of the compressor rotor, the highest values of efficiency, GDU of the compressor and resource of the blade reach .

With a decrease in the angle α _to <17 °, the range of gas-dynamic stability of the compressor operation is significantly limited, the efficiency of the stage decreases and the risk of an accidentally dangerous disruption of the air flow from the convex back of the 4 blades with the resulting loss of the HLD increases. With an increase in the angle α _to > 27 °, the risk of disruption of the air flow from the trough 3 of the pen 1 of the scapula increases and the efficiency decreases. In addition, with an increase in the angle α _to > 27 °, the voltage in the blade increases unjustifiably at all KND operation modes, which leads to a decrease in the resource, an increase in the material consumption of the blades, and ultimately to a heavier compressor and lower operational efficiency of the engine.

Similar processes take place with obtaining a positive result when observed and a negative one when going beyond the limits of the gradient ranges G in. Found in the utility model _. height H _cf pen 1 scapula. When performing three-dimensional profile of the blade with the gradient values G _{uniformizing parameter} <124.0 [deg / m], the range of GDU operation of the low pressure switch is significantly limited, the efficiency of the stage drops, and the risk of an accidentally dangerous stall of the air flow from the convex back of the 4 blades with the resulting loss of the GDU increases. Increasing the angle difference relationship Fitting 9 chord pen 1 adjustment blade to the gradient values G _{uniformizing parameter} Exceeding the upper limit _{uniformizing parameter} G > 186.8 [deg / M], leads to an unacceptable decrease in the opening angle of the peripheral section 14 of the pen 1 of the blade, which in turn leads to a decrease in efficiency, a negative decrease in the range of the GDU of the compressor and an unacceptable mismatch of the operation of the first stage of the rotor with subsequent stages of the low pressure compressor .

Gradient G _y.x. an increase in the chord 9 of the pen 1 of the scapula along the average height H _{cp of the} pen 1 of the scapula characterizes the windage of pen 1, formed as a result of the angular divergence of the inlet and outlet edges 5 and 6 of pen 1 from the sleeve to the peripheral end face 10. The sailing of pen 1 along the height of the scapula is profiled according to the mentioned gradient G _{yx of the} angular expansion of the chord of 9 feathers with the declared range of G _yx = (7.2 ÷ 10.7) · 10 ^-2 [m / m], which ensures the obtaining of a technical result of a utility model. A decrease in the ratio of the difference between the lengths of the peripheral and root chords of the pen 1 to the average height H _{cp of the} pen (G _ux <7.2 · 10 ^-2 ) leads to the formation of insufficient density of filling the peripheral annular section 14 of the cross-sectional area of the flowing part of the shoulder blade with peripheral sections 14 pen 1 blades in the projection onto a conventional plane normal to the axis of the rotor. As a result, an unacceptable decrease in the GDU stock occurs, a narrowing of the range of gas-dynamic stability of the compressor and a significant decrease in efficiency due to the possible disruption of the air flow from the back of the 4 blades. The increase (G _yx > 10.7 · 10 ^-2 ) leads to an unjustified increase in losses from friction of the flow on the profile of the pen 1 of the blade and to reduce the efficiency of the compressor.

The technical result of increasing the resource of the blade by two times is achieved subject to the condition of the ratio of the difference in thickness to the average height of the pen 1 of the blade, accepted within the specified range of the gradient values of G _equivalent = (1.25 ÷ 1.53) · 10 ^-2 [m / m] due to the provision of the required static and dynamic stiffness with optimal material consumption of the profile of the pen 1 of the blade. When the gradient values G _{reference fuel} <1.25 · 10 ^-2 [m / m] an excessive increase in material consumption occurs due to the increase in the thickness of the peripheral part of the blade that is not justified by real load combinations, which leads to an overestimation of the compressor mass and a decrease in engine efficiency. When the gradient values G _{reference fuel} > 1.53 · 10 ^-2 [m / m] the required increase in the resource of the blade is not achieved due to a decrease in dynamic strength during operation of the compressor due to an unjustified increase in the parameters of bending vibrations of the pen profile 1 with an unacceptable decrease in the maximum thickness of the profile in the most loaded peripheral part of the length feather scapula.

Thus, by improving the design and aerodynamic parameters of the blades of the impeller of the first stage, they increase the efficiency and expand the range of regimes of gas-dynamic stability of the engine’s low pressure without increasing the material consumption of the blades.

Claims (6)

1. The blade of a disk having grooves of the impeller of the first stage of the rotor of a low pressure compressor (KND) of a gas turbine engine containing a flow part having a low pressure turbine, a high pressure turbine and a power turbine, characterized in that it contains a feather that is made with an axis, convex -concave profile formed by a concave trough and a convex back, conjugated in the direction of flow of the working fluid by the input and output edges, and with a spiral twist of the profile along the height of the pen, as well as a shank with a longitudinal the first axis, intended to be installed in any of the first-stage grooves impeller disc secured angle α _{to the} profile settings of the pen to the rotor axis in a projection on a notional axial rotor plane normal to the axis of the blade having a root section pen value α _k = ( 17 ÷ 27) °, and in the peripheral section of the pen, the value α _p = (54 ÷ 64) °, and the longitudinal axis of the profile of the pen, which coincides with the axis of twist of the profile, is taken as the axis of the pen’s blade, and the feather of the blade is made with input and output edges, diverging towards the peripheral end face with gradi th increase chord G _y.h. , G _yx = (L _p.x.- L _k.h. ) / H _cp = (7.2 ÷ 10.7) · 10 ^-2 [m / m], where L _p.x - the length of the peripheral chord connecting the input and output edges of the feather blades in a conventional plane parallel to the axial plane of the rotor; L _c.h. - the length of the root chord connecting the input and output edges of the feather blades in a conventional plane parallel to the axial plane of the rotor; N _cf - the average height of the feather blades; in addition, the feather of the blade is made variable in width and height of the feather, the thickness defined in cross section as the difference in height of the back and trough relative to the conditional chord connecting the edges of the feather of the blade, while the maximum thickness of the profile of the feather of the blade is made the largest in the root section and decreasing in height of the feather to the peripheral end with a gradient of G _y.t. equal to G _y.t. = (C _to -C _p ) / N _cf = (1.25 ÷ 1.53) · 10 ^-2 [m / m], where C _to - the maximum thickness of the root section of the profile of the pen blade; With _p - the maximum thickness of the peripheral section of the profile of the pen blade; N _cf - the average height of the feather blades. 2. The blade of the impeller of the first stage of the rotor according to claim 1, characterized in that the blade is made with the angle of the profile of the pen relative to the axis of the rotor, increasing in height of the blade with a radial distance from the axis of the rotor with a gradient of G _y. in the projection onto the conditional axial plane of the rotor, the values in the range G _y.p = (α _p -α _k ) / N _cf = (124.0 ÷ 186.8) [deg / m], where α _to is the projection of the angle of the profile of the pen in the root section of the blade relative to the axis of the rotor on the conditional axial plane of the rotor, normal to the axis of the pen blade; α _p - the projection angle of the profile of the pen in the peripheral section of the blade relative to the axis of the rotor on the conditional axial plane of the rotor, normal to the axis of the pen blade; N _cf - the average height of the feather blades. 3. The blade of the impeller of the first stage of the rotor according to claim 1, characterized in that it is equipped on both sides of the pen with an anti-vibration shelf located in the region of one third of the height of the pen from the peripheral end of the blade pen, and each end of the specified shelf is made with the possibility of mutual support on the turned to it a similar end face of an adjacent impeller blade. 4. The blade of the impeller of the first stage of the rotor according to claim 1, characterized in that the feather of the blade is made of a convex-concave profile with a concave trough facing concavity in the direction of rotation of the rotor counterclockwise (view in np - direction of flight) and pen convex back facing convexity in the direction against the rotation of the rotor and in the direction of clockwise rotation, the chord connecting the inlet and outlet edges of the pen in the root zone, forms with the rotor axis in the projection onto said notional plane angle α _{to the} pro Fitting I pen least the angle α ₀ of the blade shank. 5. The blade of the impeller of the first stage of the rotor according to claim 1, characterized in that the feather of the blade is convex-concave with a concave trough facing concavity in the direction of rotation of the rotor clockwise (NP view) and with a convex back of the pen, turned convex to the side against the rotation of the rotor and against the direction of rotation of the clockwise direction (view in np). 6. The blade of the impeller of the first stage of the rotor according to claim 1, characterized in that the peripheral end of the feather of the blade is made beveled with a repetition of the curvature of the inner surface of the engine duct in the area of the first stage of the low pressure valve with a decrease in radius in the direction of flow of the working fluid with a height sufficient for unhindered rotation of the blades of the impeller in the rotor of the low pressure valve

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