A tenon blade with three pressure-sensing holes on the leading edge of the primitive level

Abstract

The present invention discloses a tenon blade with three pressure-sensing holes at the leading edge of a primitive stage, comprising pressure-sensing holes, a pressure-inducing channel, a blade top tenon, a pressure-inducing pipe interface, and a low-loss bend pipe. The leading edge of the blade has multiple rows of pressure-sensing holes along the blade height direction, and each row comprises three pressure-sensing holes, which are respectively distributed at the leading edge point of the primitive stage, the pressure surface, and the suction surface; the pressure-inducing channel is respectively connected to the orifice of the pressure-sensing hole and the pressure-inducing pipe interface, and a low-loss bend pipe is used at the bend. The present invention can simultaneously measure the total pressure, static pressure, deflection angle, and Mach number of the airflow at the outlet of the compressor rotor along the blade height direction and at multiple primitive stage positions, and is suitable for measuring the distribution of the two-dimensional flow field parameters at the rotor outlet along the blade height direction. The present invention not only has the aerodynamic performance and strength of conventional blades, but more importantly, has the function of measuring aerodynamic parameters. Compared with conventional probes and blade-shaped probe measurement technologies, the present invention has no protruding probe, does not interfere with the measured flow field structure, does not affect the aerodynamic performance of the blade itself, and has high accuracy in measuring parameters.

Description

Technical Field

[0001] The invention belongs to the field of power machinery and relates to a compressor, and in particular to a tenon-type blade with three pressure-sensing holes at the leading edge of a primitive stage. Background Art

[0002] There are many ways to install compressor stator blades on the casing, one of the more common installation methods is the circumferential tenon-groove connection. Specifically, the blade has a tenon on the blade top, and the blade can be slid into the circumferential tenon groove on the casing through the tenon, and then the blade is fixed with a lock plate or rivet. This installation method can avoid opening holes on the casing and make the layout between the blades more compact.

[0003] In a compressor, a cylindrical surface coaxial with the compressor is used to cut the compressor blades. The cross-section of the compressor blades is called the elementary stage of the blades.

[0004] At present, in the aerodynamic design process of compressor blades, the velocity triangle of the compressor inlet and outlet must be determined first according to the compressor flow, the compressor inner and outer diameters, the design speed and other parameters. The inlet and outlet angles of the primitive stage can be obtained by calculating the inlet and outlet velocity triangles. Different attack angles are given for primitive stages at different positions. Combined with the backward angle, the leading edge angle and the trailing edge angle of the blade, the installation angle corresponding to each primitive stage can be obtained. The obtained primitive stages can then be stacked to obtain the three-dimensional shape of the blade.

[0005] In addition, the strength design of the compressor blades is also required to ensure that the blades have sufficient strength. Therefore, the design process of the blades requires repeated iterations of multi-parameter optimization design. On the premise of ensuring that the compressor blades have sufficient strength, designers also hope that the weight of the blades is as light as possible, which is conducive to reducing the overall weight of the aircraft engine or gas turbine and improving the thrust-to-weight ratio of the aircraft engine or the efficiency of the gas turbine.

[0006] The flow inside the compressor is complex, highly three-dimensional and non-steady, and the blade structure and profile are complex, and the axial space between the rotor and the stator is very narrow. In addition, the test site environment is harsh, and there are often problems such as vibration and oil mist, which limits conventional testing methods.

[0007] Contact measurement methods such as pressure probes, including pressure probe combs and blade probes that can achieve multi-point simultaneous measurement, mostly have forward-extending probes. The pressure probe comb is limited by its own size and cannot be inserted into the narrow flow channel between small-sized blade rows to carry out interstage flow field parameter testing. Even if it can be inserted, the probe head and support rod will cause great interference to the measured flow field.

[0008] The blade profile probe can be extended into the narrow flow channel between the small-sized blade rows to carry out inter-stage flow field parameter testing, but it will cause great interference to the measured flow field, especially the flow field near the blade wall, destroy the original structure of the flow field, cause large measurement errors, and even deteriorate the original aerodynamic load of the blade and compressor performance.

[0009] Hot wire anemometer is also one of the commonly used test methods for the flow field in the compressor, but the hot wire is easy to break and is easily contaminated by impurities, resulting in inaccurate measurement results.

[0010] Although non-contact measurement methods such as particle image velocimetry and laser Doppler velocimetry will not destroy the flow field structure, the flow field in the blade root area cannot be measured due to the complex blade surface blocking the laser or the narrow flow channel blocking the laser. In addition, when the laser is irradiated on the wall, it will produce strong reflections, causing measurement errors. Particle tracking problems can also lead to large measurement errors. Particle image velocimetry and laser Doppler velocimetry can only measure speed, not pressure, and compressor performance experiments are more concerned with pressure data.

[0011] The existing compressor blade design does not include the inter-stage aerodynamic parameter measurement design, resulting in the inability to carry out accurate testing of the inter-stage flow field parameters in the narrow flow passages between the small-sized compressor blade rows. Summary of the invention

[0012] The technical problem to be solved by the present invention is: in view of the fact that the existing compressor blade design does not include a design for measuring inter-stage aerodynamic parameters, resulting in the difficulty in accurately measuring the inter-stage flow field parameters in the narrow flow passage between the rows of small-sized compressor blades, a tenon-type blade with three pressure-sensing holes on the leading edge of the elementary stage is invented to solve the technical problem that the inter-stage flow field parameters cannot be accurately measured in the narrow flow passage between the rows of small-sized compressor blades.

[0013] The technical solution of the present invention is:

[0014] A tenon-type blade with three pressure-sensing holes at the leading edge of a primitive level, characterized in that: a blade suction surface (1), a blade pressure surface (2), a suction surface pressure sensing hole (3), a leading edge point pressure sensing hole (4), a pressure surface pressure sensing hole (5), a pressure induction channel (6), a low-loss bent pipe (7), a blade top tenon (8), and a pressure induction pipe interface (9); the leading edge of the blade has multiple rows of pressure sensing holes along the blade height direction, each row includes three pressure sensing holes located on the blade surface, namely, a leading edge point pressure sensing hole (4) located at the leading edge point of the blade, a suction surface pressure sensing hole (3) located at the suction surface (1) of the blade, and a pressure surface pressure sensing hole (5) located at the pressure surface (2) of the blade, the center lines of the three holes are located on the same blade primitive level, and the diameter of the pressure sensing hole is 0.2 mm to 1 mm; wherein, the center line of the leading edge point pressure sensing hole (4) and the primitive level where it is located are parallel to each other. The tangent of the middle arc line of the stage coincides with the tangent of the leading edge point, the center line of the pressure sensing hole (3) on the suction surface is the normal line of the suction surface at the point where the length of the middle arc line of the elementary stage is 0.5% to 20% from the leading edge point of the elementary stage, and the center line of the pressure sensing hole (5) on the pressure surface is the normal line of the pressure surface at the point where the length of the middle arc line of the elementary stage is 0.5% to 20% from the leading edge point of the elementary stage; one end of the pressure-inducing channel (6) is connected to the orifice of the pressure-inducing hole, and the other end is connected to the pressure-inducing pipe interface (9) located in the blade top tenon (8); the diameter of the pressure-inducing channel (6) is consistent with that of the pressure-inducing hole, which is 0.2 mm to 1 mm; the pressure-inducing channel (6) extends from the elementary stage of the blade to the trailing edge of the blade, and bends toward the blade top tenon (8) at the point where the length of the middle arc line is 10% to 80% from the leading edge point of the elementary stage, and a low-loss bend pipe (7) is used at the bend; the center line of the low-loss bend pipe (7) is the polar coordinate curve ρ 2 =a 2 A portion of sin2θ, wherein the value of a is 1 to 4 times the diameter of the pressure channel (6), and the curve segment with a value of θ between 0 and 30° is the center line of the low-loss bent pipe (7), which is tangent to the center lines of the two connected sections of the pressure channel (6); for blades with less bending and twisting, the bent pressure channel (6) adopts a straight channel design, and for blades with bending and twisting, the center line of the bent pressure channel (6) is a curve connecting the corresponding points of each elementary level; the center line of the pressure channel interface (9) coincides with the center line of the end of the pressure channel (6), the length is 2mm to 20mm, and the diameter is 0.4mm to 2mm; after the pressure channel is connected to the pressure channel interface (9) in the blade top tenon (8), it is routed along the gap between the tenon groove and the blade top tenon (8) and led out from the opening on the casing;

[0015] A tenon-type blade with three pressure-sensing holes at the leading edge of a primitive level, characterized in that: the invention has multiple rows of pressure-sensing holes; the row closest to the blade root is 0.2 to 1 mm away from the blade root; the row closest to the blade top is 0.2 to 1 mm away from the blade top; within 25% of the leaf height near the blade root or near the blade top, the spacing between two adjacent rows of pressure-sensing holes is 5% to 15% of the leaf height, and the spacing between two adjacent rows of pressure-sensing holes at the remaining leaf heights is 10% to 20% of the leaf height.

[0016] The pressure felt by the pressure sensing hole is transmitted to the pressure sensor through the pressure-guiding channel and the pressure-guiding pipe; the pressure sensor converts the pressure signal into an electrical signal for output, and the electrical signal output by the pressure sensor can be converted into a pressure value measured by the pressure sensing hole through a computer data acquisition and processing system; the tenon-type blade with three pressure-sensing holes at the leading edge of the elementary stage of the present invention can be calibrated in a calibration wind tunnel to obtain the pressure values ​​of the three pressure-sensing holes of each elementary stage under different incoming flow Mach numbers and different incoming flow deflection angles, and the total pressure coefficient can be calculated by combining the known incoming flow total pressure and static pressure. , static pressure coefficient, airflow deflection angle coefficient, etc.; a tenon-type blade with three pressure-sensing holes at the leading edge of a primitive stage of the present invention can obtain the pressure felt by the three pressure-sensing holes on each primitive after being installed in the compressor in actual work, and the total pressure coefficient, static pressure coefficient and airflow deflection angle coefficient obtained in the calibration wind tunnel can be used to obtain the total pressure, static pressure, Mach number and airflow deflection angle data of the actual incoming flow; since the present invention has multiple rows of pressure-sensing holes, the two-dimensional flow field parameter distribution of the compressor rotor outlet at multiple blade primitive stage positions along the blade height direction can be measured simultaneously.

[0017] The beneficial effects of the present invention are:

[0018] The distance between the pressure-inducing channels of the present invention is large and the distribution is reasonable, which will not have an adverse effect on the strength of the blades. The pressure-inducing channels adopt low-loss elbows, which can effectively reduce pressure loss and avoid stress concentration, and can reduce the weight of the blades. The present invention not only has the aerodynamic performance and strength of conventional blades, but more importantly, has the function of simultaneously measuring parameters such as the total pressure, static pressure, Mach number, airflow deflection angle, etc. of the two-dimensional flow field at multiple blade primitive level positions along the blade height direction; since the two-dimensional flow field parameters can be measured without inserting a pressure probe, and no extended probe is required, the measured flow field will not be damaged, the flow characteristics of the blade itself will not be affected, and no additional measurement errors will be introduced; compared with the blade type probe, the absence of an extended probe means that the present invention is lighter in weight, which is beneficial to reducing the overall weight of the compressor test piece; another benefit brought by not needing an extended probe is that the pressure sensing hole near the blade root can be set very close to the blade root, and the pressure sensing hole near the blade top can also be set very close to the blade top, thereby improving the measurement resolution at the blade root and the blade top; compared with the existing blades, the present invention fully considers the aerodynamic, structural, strength, and weight design of the blade, and creatively proposes the position, size, and design and layout of the pressure-inducing channel of the pressure sensing hole, and has outstanding characteristics and substantial progress in the design of compressor blades and aerodynamic experimental measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional structural diagram of a tenon-type blade with three pressure-sensing holes on the leading edge of the primitive level.

[0020] Figure 2 yes Figure 1 Axonometric drawing of .

[0021] Figure 3 yes Figure 1 Left view of .

[0022] Figure 4 yes Figure 1 Right view of .

[0023] Figure 5 yes Figure 3 Cross section at the BB position.

[0024] Figure 6 yes Figure 5 A partial enlarged view of .

[0025] Figure 7 yes Figure 3 Cross section at position AA.

[0026] Figure 8 yes Figure 3 A primitive level.

[0027] Fig. 9A schematic plan view of the structure of a second embodiment of a tenon-type blade having three pressure-sensing holes at the leading edge of a primitive level.

[0028] Fig.10 yes Fig. 9 A partial enlarged view of .

[0029] Fig.11 yes Fig. 9 Left view of .

[0030] Fig.12 yes Fig. 9 Two primitive levels.

[0031] Fig.13 It is the definition of the centerline of a low-loss elbow.

[0032] Fig.14 It is a schematic diagram of a mortise-type blade with three pressure-sensing holes on the leading edge of the primitive stage being assembled to the casing.

[0033] Among them: 1-blade suction surface, 2-blade pressure surface, 3-suction surface pressure sensing hole, 4-front edge pressure sensing hole, 5-pressure surface pressure sensing hole, 6-pressure channel, 7-low-loss bent pipe, 8-blade top tenon, 9-pressure pipe interface, 10-5% length point of the primitive level center arc line starting from the primitive level front edge point, 11-primitive level front edge point, 12-primitive level center arc line, 13-blade profile inscribed circle, 14-1 / 3 blade thickness, 15-primitive level trailing edge point, 16-30% length point of the primitive level center arc line starting from the primitive level front edge point, 17-30% length point of another primitive level center arc line starting from the primitive level front edge point, 18-opening on the casing, 19-gap between the casing and the tenon. DETAILED DESCRIPTION

[0034] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Embodiment 1

[0036] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, this embodiment introduces a tenon-type blade with three pressure-sensing holes at the leading edge of the elementary level; the blade has very small bending and twisting, and comprises a blade suction surface (1), a blade pressure surface (2), a suction surface pressure sensing hole (3), a leading edge point pressure sensing hole (4), a pressure surface pressure sensing hole (5), a pressure-inducing channel (6), a low-loss bend pipe (7), a blade top tenon (8), and a pressure-inducing pipe interface (9). The blade has multiple rows of pressure sensing holes distributed along the blade height direction, and the center line of each row of pressure sensing holes is on the same elementary level, and the diameter of each hole is 0.4 mm. From the direction of the blade root, the first row of pressure sensing holes is 1 mm away from the blade root, the second row is at 25% of the blade height, the third row is at 50% of the blade height, the fourth row is at 75% of the blade height, and the fifth row is 1 mm away from the blade top; the pressure-inducing channel (6) is a passage inside the blade, and its diameter is the same as the diameter of the pressure sensing hole, which is 0.4 mm; one end of the pressure-inducing channel is connected to the orifice of the pressure sensing hole, and the other end is connected to the pressure-inducing pipe interface (9), and the length of the pressure-inducing pipe interface is 10 mm and the diameter is 0.8 mm.

[0037] Figure 5 is a primitive level cross section at the middle of the leaf of the present invention, Figure 6 yes Figure 5 A partial enlarged view of Figure 7 is a basic level cross section at the blade root of the present invention; Figure 5 , the center line of the leading edge point pressure sensing hole (4) coincides with the tangent line of the elementary level mid-arc at the leading edge point, the center line of the suction surface pressure sensing hole (3) is the normal line of the suction surface passing through the elementary level mid-arc at a length point (10) of 5% from the elementary level leading edge point, and the center line of the pressure surface pressure sensing hole (5) is the normal line of the pressure surface passing through the elementary level mid-arc at a length point (10) of 5% from the elementary level leading edge point; as Figure 5 The pressure induction channel (6) connected to the leading edge pressure sensing hole extends to the rear of the blade in the form of a straight channel at the elementary level where it is located. The pressure induction channel connecting the suction surface and the pressure surface pressure sensing holes is bent and parallel to the pressure induction channel connecting the leading edge pressure sensing hole (4). The bending part adopts a low-loss elbow (7) design; Figure 7 The pressure-inducing channels behind the leading edge pressure sensing holes of the first row to the fifth row from the direction of the blade top tenon (8) are bent toward the blade top tenon (8) at the points of 20%, 30%, 40%, 50% and 60% of the mid-arc length from the leading edge of the blade, respectively, and low-loss elbows (7) are used at the bending points; Fig.13 , the center line of the low-loss elbow (7) is the polar coordinate curve ρ 2 =a 2 A portion of sin2θ is the solid line portion in the figure, wherein the value of a is twice the diameter of the pressure-inducing channel; the curve segment with a value of θ between 0 and 30° is the center line of the low-loss elbow (7), which is tangent to the center lines of the two connected sections of the pressure-inducing channel (6) respectively; the pressure-inducing channel (6) after bending is a straight channel.

[0038] Figure 8 The position where the pressure-inducing channel (6) connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the blade top tenon (8) on the elementary level is indicated; the elementary level inscribed circle (13) at the 2% mid-arc length behind the bending point of the pressure-inducing channel (6) connecting the leading edge point pressure-sensing hole (4) is taken, and points at a distance of 1 / 3 of the blade thickness (14) from the suction surface and the pressure surface are taken on the line connecting the tangent points of the circle with the suction surface (1) and the pressure surface (2), respectively, and these two points are taken as the bending points of the pressure-inducing channel connecting the pressure-sensing holes on the suction surface and the pressure surface; the pressure-inducing channel connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the blade top tenon (8) at these two points, and a low-loss elbow (7) design is adopted at the bending point, and the pressure-inducing channel (6) after bending is a straight channel.

[0039] The blade is circumferentially slid into the tenon groove on the casing through the blade top tenon (8) and fixed. The pressure pipe is connected to the pressure pipe interface (9) in the blade top tenon (8), and then routed along the gap between the tenon groove and the blade top tenon and led out through the opening on the casing.

[0040] Embodiment 2

[0041] like Fig. 9 and Fig.11 As shown, this embodiment introduces a tenon-type blade with three pressure-sensing holes at the leading edge of the elementary level; the blade has a certain degree of bending and twisting, and includes a blade suction surface (1), a blade pressure surface (2), a suction surface pressure sensing hole (3), a leading edge point pressure sensing hole (4), a pressure surface pressure sensing hole (5), a pressure-inducing channel (6), a low-loss bend pipe (7), a blade top tenon (8), and a pressure-inducing pipe interface (9). Among them, the blade has multiple rows of pressure sensing holes distributed along the blade height direction, and the center line of each row of pressure sensing holes is on the same elementary level, and the diameter of each hole is 0.4 mm. From the direction of the blade root, the first row of pressure sensing holes is 1 mm away from the blade root, the second row is at 25% of the blade height, the third row is at 50% of the blade height, the fourth row is at 75% of the blade height, and the fifth row is 1 mm away from the blade top; the pressure-inducing channel (6) is a passage inside the blade, and its diameter is the same as the diameter of the pressure sensing hole, which is 0.4 mm; one end of the pressure-inducing channel is connected to the orifice of the pressure sensing hole, and the other end is connected to the pressure-inducing pipe interface (9), and the length of the pressure-inducing pipe interface is 10 mm and the diameter is 0.8 mm.

[0042] Figure 5 is a primitive level cross section at the middle of the leaf of the present invention, Figure 6 yes Figure 5 A partial enlarged view of Figure 7 is a basic level cross section at the blade root of the present invention; Figure 5, the center line of the leading edge point pressure sensing hole (4) coincides with the tangent line of the elementary level mid-arc at the leading edge point, the center line of the suction surface pressure sensing hole (3) is the normal line of the suction surface passing through the elementary level mid-arc at a length point (10) of 5% from the elementary level leading edge point, and the center line of the pressure surface pressure sensing hole (5) is the normal line of the pressure surface passing through the elementary level mid-arc at a length point (10) of 5% from the elementary level leading edge point; as Figure 5 The pressure induction channel (6) connected to the leading edge pressure sensing hole extends to the rear of the blade in the form of a straight channel at the elementary level where it is located. The pressure induction channel connecting the suction surface and the pressure surface pressure sensing holes is bent and parallel to the pressure induction channel connecting the leading edge pressure sensing hole (4). The bending part adopts a low-loss elbow (7) design; Figure 7 The pressure-inducing channels behind the leading edge pressure sensing holes of the first row to the fifth row from the direction of the blade top tenon (8) are bent toward the blade top tenon (8) at the points of 20%, 30%, 40%, 50% and 60% of the mid-arc length from the leading edge of the blade, respectively, and low-loss elbows (7) are used at the bending points; Fig.13 , the center line of the low-loss elbow (7) is the polar coordinate curve ρ 2 =a 2 A portion of sin2θ is the solid line portion in the figure, where the value of a is twice the diameter of the pressure-inducing channel; the curve segment with a value of θ between 0 and 30° is taken as the center line of the low-loss elbow (7), which is tangent to the center lines of the two connected sections of the pressure-inducing channel (6) respectively.

[0043] Figure 8 The position where the pressure-inducing channel (6) connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the blade top tenon (8) on the elementary level is indicated; the elementary level inscribed circle (13) at the length of the mid-arc line 2% behind the bending point of the pressure-inducing channel (6) connecting the leading edge point pressure-sensing hole (4) is taken, and points at a distance of 1 / 3 of the blade thickness (14) from the suction surface and the pressure surface are taken on the line connecting the circle with the tangent points of the suction surface and the pressure surface, respectively, and these two points are taken as the bending points of the pressure-inducing channel connecting the pressure-sensing holes on the suction surface and the pressure surface; the pressure-inducing channel connecting the pressure-sensing holes on the suction surface and the pressure surface is bent toward the blade top tenon (8) at these two points, and a low-loss elbow (7) design is adopted at the bending point.

[0044] Fig.12 Schematic diagram of the position of the center line of the pressure-inducing channel (6) inside the twisted blade after bending toward the blade top tenon (8); due to the twisting of the blade, the pressure-inducing channel cannot reach the end of the blade top tenon (8) in the form of a straight channel after bending at the primitive level, so the center line of the pressure-inducing channel is a curve connecting the corresponding points on each primitive level. To better illustrate this point, Fig.12Taking the two blade primitive levels in the example, if the pressure-inducing channel (6) bends at the point (16) where the arc line of the primitive level is 30% of the length starting from the leading edge point of the primitive level, then the center line of the pressure-inducing channel and the line connecting the points where the arc lines of all primitive levels below the primitive level are 30% of the length starting from the leading edge point of the primitive level coincide with each other.

[0045] The blade slides into the tenon groove on the casing through the blade top tenon (8) along the circumferential direction and is fixed. The pressure pipe is connected to the pressure pipe interface (9) in the blade top tenon (8), and then routed along the gap between the tenon groove and the blade top tenon and led out through the opening on the casing.

[0046] Embodiment 3

[0047] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, this embodiment introduces a tenon-type blade with three pressure-sensing holes at the leading edge of the elementary level; the blade has very small bending and twisting, and comprises a blade suction surface (1), a blade pressure surface (2), a suction surface pressure sensing hole (3), a leading edge point pressure sensing hole (4), a pressure surface pressure sensing hole (5), a pressure-inducing channel (6), a low-loss bend pipe (7), a blade top tenon (8), and a pressure-inducing pipe interface (9). The blade has multiple rows of pressure sensing holes distributed along the blade height direction, and the center line of each row of pressure sensing holes is on the same elementary level, and the diameter of each hole is 0.4 mm. From the direction of the blade root, the first row of pressure sensing holes is 1 mm away from the blade root, the second row is at 25% of the blade height, the third row is at 50% of the blade height, the fourth row is at 75% of the blade height, and the fifth row is 1 mm away from the blade top; the pressure-inducing channel (6) is a passage inside the blade, and its diameter is the same as the diameter of the pressure sensing hole, which is 0.4 mm; one end of the pressure-inducing channel is connected to the orifice of the pressure sensing hole, and the other end is connected to the pressure-inducing pipe interface (9), and the length of the pressure-inducing pipe interface is 10 mm and the diameter is 0.8 mm.

[0048] Figure 5 is a primitive level cross section at the middle of the leaf of the present invention, Figure 6 yes Figure 5 A partial enlarged view of Figure 7 is a basic level cross section at the blade root of the present invention; Figure 5 , the center line of the leading edge point pressure sensing hole (4) coincides with the tangent line of the elementary level mid-arc at the leading edge point, the center line of the suction surface pressure sensing hole (3) is the normal line of the suction surface passing through the elementary level mid-arc at a length point (10) of 5% from the elementary level leading edge point, and the center line of the pressure surface pressure sensing hole (5) is the normal line of the pressure surface passing through the elementary level mid-arc at a length point (10) of 5% from the elementary level leading edge point; as Figure 5The pressure induction channel (6) connected to the leading edge pressure sensing hole extends to the rear of the blade in the form of a straight channel at the elementary level where it is located. The pressure induction channel connecting the suction surface and the pressure surface pressure sensing holes is bent and parallel to the pressure induction channel connecting the leading edge pressure sensing hole (4). The bending part adopts a low-loss elbow (7) design; Figure 7 The pressure-inducing channels behind the leading edge pressure sensing holes of the first row to the fifth row from the direction of the blade top tenon (8) are bent toward the blade top tenon (8) at the points of 20%, 30%, 40%, 50% and 60% of the mid-arc length from the leading edge of the blade, respectively, and low-loss elbows (7) are used at the bending points; Fig.13 , the center line of the low-loss elbow (7) is the polar coordinate curve ρ 2 =a 2 A portion of sin2θ is the solid line portion in the figure, wherein the value of a is twice the diameter of the pressure-inducing channel; the curve segment with a value of θ between 0 and 30° is taken as the center line of the low-loss elbow (7), which is tangent to the center lines of the two connected sections of the pressure-inducing channel (6) respectively; the pressure-inducing channel (6) after bending is a straight channel.

[0049] Figure 8 The position where the pressure-inducing channel (6) connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the blade top tenon (8) on the elementary level is indicated; the elementary level inscribed circle (13) at the 2% mid-arc length behind the bending point of the pressure-inducing channel (6) connecting the leading edge point pressure-sensing hole (4) is taken, and points at a distance of 1 / 3 of the blade thickness (14) from the suction surface and the pressure surface are taken on the line connecting the circle with the tangent points of the suction surface and the pressure surface, respectively, and these two points are taken as the bending points of the pressure-inducing channel connecting the pressure-sensing holes on the suction surface and the pressure surface; the pressure-inducing channel connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the blade top tenon (8) at these two points, and a low-loss elbow (7) design is adopted at the bending point, and the pressure-inducing channel (6) after bending is a straight channel.

[0050] Fig.10 yes Fig. 9 A partial enlarged view of the middle blade top tenon (8); in this embodiment, the pressure-inducing channel (6) and the pressure-inducing pipe interface (9) are connected by a conical surface transition, and the length of this connecting section is 10 mm.

[0051] The blade is circumferentially slid into the tenon groove on the casing through the blade top tenon (8) and fixed. The pressure pipe is connected to the pressure pipe interface (9) in the blade top tenon (8), and then routed along the gap between the tenon groove and the blade top tenon and led out through the opening on the casing.

[0052] Embodiment 4

[0053] like Fig. 9 and Fig.11As shown, this embodiment introduces a tenon-type blade with three pressure-sensing holes at the leading edge of the elementary level; the blade has a certain degree of bending and twisting, and includes a blade suction surface (1), a blade pressure surface (2), a suction surface pressure sensing hole (3), a leading edge point pressure sensing hole (4), a pressure surface pressure sensing hole (5), a pressure-inducing channel (6), a low-loss bend pipe (7), a blade top tenon (8), and a pressure-inducing pipe interface (9). Among them, the blade has multiple rows of pressure sensing holes distributed along the blade height direction, and the center line of each row of pressure sensing holes is on the same elementary level, and the diameter of each hole is 0.4 mm. From the direction of the blade root, the first row of pressure sensing holes is 1 mm away from the blade root, the second row is at 25% of the blade height, the third row is at 50% of the blade height, the fourth row is at 75% of the blade height, and the fifth row is 1 mm away from the blade top; the pressure-inducing channel (6) is a passage inside the blade, and its diameter is the same as the diameter of the pressure sensing hole, which is 0.4 mm; one end of the pressure-inducing channel is connected to the orifice of the pressure sensing hole, and the other end is connected to the pressure-inducing pipe interface (9), and the length of the pressure-inducing pipe interface is 10 mm and the diameter is 0.8 mm.

[0054] Figure 5 is a primitive level cross section at the middle of the leaf of the present invention, Figure 6 yes Figure 5 A partial enlarged view of Figure 7 is a basic level cross section at the blade root of the present invention; Figure 5 , the center line of the leading edge point pressure sensing hole (4) coincides with the tangent line of the elementary level mid-arc at the leading edge point, the center line of the suction surface pressure sensing hole (3) is the normal line of the suction surface passing through the elementary level mid-arc at a length point (10) of 5% from the elementary level leading edge point, and the center line of the pressure surface pressure sensing hole (5) is the normal line of the pressure surface passing through the elementary level mid-arc at a length point (10) of 5% from the elementary level leading edge point; as Figure 5 The pressure induction channel (6) connected to the leading edge pressure sensing hole extends to the rear of the blade in the form of a straight channel at the elementary level where it is located. The pressure induction channel connecting the suction surface and the pressure surface pressure sensing holes is bent and parallel to the pressure induction channel connecting the leading edge pressure sensing hole (4). The bending part adopts a low-loss elbow (7) design; Figure 7 The pressure-inducing channels behind the leading edge pressure sensing holes of the first row to the fifth row from the direction of the blade top tenon (8) are bent toward the blade top tenon (8) at the points of 20%, 30%, 40%, 50% and 60% of the mid-arc length from the leading edge of the blade, respectively, and low-loss elbows (7) are used at the bending points; Fig.13 , the center line of the low-loss elbow (7) is the polar coordinate curve ρ 2 =a 2 A portion of sin2θ is the solid line portion in the figure, where the value of a is twice the diameter of the pressure-inducing channel; the curve segment with a value of θ between 0 and 30° is taken as the center line of the low-loss elbow (7), which is tangent to the center lines of the two connected sections of the pressure-inducing channel (6) respectively.

[0055] Figure 8 The position where the pressure-inducing channel (6) connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the blade top tenon (8) on the elementary level is indicated; the elementary level inscribed circle (13) at the length of the mid-arc line 2% behind the bending point of the pressure-inducing channel (6) connecting the leading edge point pressure-sensing hole (4) is taken, and points at a distance of 1 / 3 of the blade thickness (14) from the suction surface and the pressure surface are taken on the line connecting the circle with the tangent points of the suction surface and the pressure surface, respectively, and these two points are taken as the bending points of the pressure-inducing channel connecting the pressure-sensing holes on the suction surface and the pressure surface; the pressure-inducing channel connecting the pressure-sensing holes on the suction surface and the pressure surface is bent toward the blade top tenon (8) at these two points, and a low-loss elbow (7) design is adopted at the bending point.

[0056] Fig.12 Schematic diagram of the position of the center line of the pressure-inducing channel (6) inside the twisted blade after bending toward the blade top tenon (8); due to the twisting of the blade, the pressure-inducing channel cannot reach the end of the blade top tenon (8) in the form of a straight channel after bending in the primitive level, so the center line of the pressure-inducing channel is a curve connecting the corresponding points on each primitive level. To better illustrate this point, Fig.12 Taking the two blade primitive levels in the example, if the pressure-inducing channel (6) bends at the point (16) where the arc line of the primitive level is 30% of the length starting from the leading edge point of the primitive level, then the center line of the pressure-inducing channel and the line connecting the points where the arc lines of all primitive levels below the primitive level are 30% of the length starting from the leading edge point of the primitive level coincide with each other.

[0057] Fig.10 yes Fig. 9 A partial enlarged view of the middle blade top tenon (8); in this embodiment, the pressure-inducing channel (6) and the pressure-inducing pipe interface (9) are connected by a conical surface transition, and the length of this connecting section is 10 mm.

[0058] The blade is circumferentially slid into the tenon groove on the casing through the blade top tenon (8) and fixed. The pressure pipe is connected to the pressure pipe interface (9) in the blade top tenon (8), and then routed along the gap between the tenon groove and the blade top tenon and led out through the opening on the casing.

Claims

1. A tenon blade with three pressure-sensing holes on the leading edge of the elementary level, characterized in that: A blade suction surface (1), a blade pressure surface (2), a suction surface pressure sensing hole (3), a leading edge point pressure sensing hole (4), a pressure surface pressure sensing hole (5), a pressure induction channel (6), a low-loss bent pipe (7), a blade top tenon (8), and a pressure induction pipe interface (9); the leading edge of the blade has multiple rows of pressure sensing holes along the blade height direction, each row comprising three pressure sensing holes located on the blade surface, namely, a leading edge point pressure sensing hole (4) located at the leading edge point of the blade, a suction surface pressure sensing hole (3) located at the suction surface (1) of the blade, and a pressure surface pressure sensing hole (5) located at the pressure surface (2) of the blade, the center lines of the three holes are located on the same blade elemental level, and the diameter of the pressure sensing hole is 0.2 mm to 1 mm; wherein, the tangent line between the center line of the leading edge point pressure sensing hole (4) and the mid-arc line of the elemental level to which it is located at the leading edge point The center line of the pressure sensing hole (3) on the suction side is the normal line of the suction side at a point where the length of the mid-arc line of the elemental stage is 0.5% to 20% from the front edge point of the elemental stage, and the center line of the pressure sensing hole (5) on the pressure side is the normal line of the pressure side at a point where the length of the mid-arc line of the elemental stage is 0.5% to 20% from the front edge point of the elemental stage; one end of the pressure-inducing channel (6) is connected to the orifice of the pressure sensing hole, and the other end is connected to the pressure-inducing pipe interface (9) located in the blade top tenon (8); the diameter of the pressure-inducing channel (6) is consistent with that of the pressure sensing hole, which is 0.2 mm to 1 mm; the pressure-inducing channel (6) extends from the blade elemental stage where it is located to the trailing edge of the blade, and bends toward the blade top tenon (8) at a point where the length of the mid-arc line is 10% to 80% from the front edge point of the elemental stage, and a low-loss bend pipe (7) is used at the bend; the center line of the low-loss bend pipe (7) is the polar coordinate curve ρ 2 =a 2 a portion of sin2θ, wherein the value of a is 1 to 4 times the diameter of the pressure channel (6), and the curve segment with a value of θ between 0 and 30° is the center line of the low-loss bent pipe (7), which is tangent to the center lines of the two connected sections of the pressure channel (6); for blades with less bending and twisting, the bent pressure channel (6) adopts a straight channel design, and for blades with bending and twisting, the center line of the bent pressure channel (6) is a curve connecting the corresponding points of each element level; the center line of the pressure channel interface (9) coincides with the center line of the end of the pressure channel (6), the length is 2 mm to 20 mm, and the diameter is 0.4 mm to 2 mm; after the pressure channel is connected to the pressure channel interface (9) in the blade top tenon (8), it is routed along the gap between the tenon groove and the blade top tenon (8) and led out from the opening on the casing; The blade has multiple rows of pressure sensing holes; the row closest to the leaf root is 0.2 to 1 mm away from the leaf root; the row closest to the leaf top is 0.2 to 1 mm away from the leaf top; within 25% of the leaf height near the leaf root or near the leaf top, the spacing between two adjacent rows of pressure sensing holes is 5% to 15% of the leaf height, and the spacing between two adjacent rows of pressure sensing holes at the rest of the leaf heights is 10% to 20% of the leaf height.

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