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

Abstract

The present invention discloses a handle-type blade with three pressure-sensing holes at the leading edge of a primitive stage, comprising pressure sensing holes, a pressure-inducing channel, a handle, 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, in particular to a handle-type blade with three pressure-sensing holes on the leading edge of a primitive stage. Background Art

[0002] There are many ways to install the compressor stator blades on the hub, one of which is the handle fixing method. The stator blade root has a handle boss and a handle, and the blade can be fixed to the hub through the clamp ring, clamp ring and other structures on the hub. This installation method has a simple structure and is easy to disassemble and assemble, making it easy to disassemble and replace a single blade.

[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 handle-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 handle-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 handle boss (8), a handle (9), and a pressure induction pipe interface (10); 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 diameters of the pressure sensing holes are 0.2 mm to 1 mm; wherein the center line of the leading edge point pressure sensing hole (4) is parallel to the center line of the leading edge point pressure sensing hole (4). The tangent of the middle arc line of the elementary level at the leading edge point coincides, the center line of the pressure sensing hole (3) on the suction side is the normal line of the suction side at the point where the middle arc line of the elementary level starts from the leading edge point of the elementary level at 0.5% to 20% of the length, and the center line of the pressure sensing hole (5) on the pressure side is the normal line of the pressure side at the point where the middle arc line of the elementary level starts from the leading edge point of the elementary level at 0.5% to 20% of the length; 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 (10) located in the handle (9); 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 level of the blade to the trailing edge of the blade, and bends toward the handle (9) at the point where the middle arc line length is 30% to 50% from the leading edge point of the elementary level, 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 pressure channel (6) after bending adopts a straight channel design, and for blades with bending and twisting, the center line of the pressure channel (6) after bending is a curve connecting the corresponding points of each elementary level; the center line of the pressure channel interface (10) 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; the pressure tube is connected to the pressure tube interface (10) in the handle (9) and then led out through the opening on the hub;

[0015] A handle-type blade with three pressure-sensing holes at the leading edge of the 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 the pressure value measured by the pressure sensing hole through a computer data acquisition and processing system; the handle-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 handle-type blade with three pressure-sensing holes on 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 stage in actual work after being installed in the compressor, 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 The schematic diagram of the planar structure of a handle-type blade with three pressure-sensing holes on the leading edge of the primitive level.

[0020] Figure 2 yes Figure 1 Left view of .

[0021] Figure 3 yes Figure 1 Cross section at the BB position.

[0022] Figure 4 yes Figure 3 A partial enlarged view of .

[0023] Figure 5 yes Figure 1 Cross section at position AA.

[0024] Figure 6 yes Figure 1 A primitive level.

[0025] Figure 7 A schematic plan view of the structure of a second embodiment of a handle-type blade having three pressure-sensing holes at the leading edge of a primitive level.

[0026] Figure 8 yes Figure 7 Left view of .

[0027] Fig. 9 yes Figure 7 The main view is shown with a partial cross-section.

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

[0029] Fig.11 yes Figure 7 Two primitive levels.

[0030] Fig.12 It is the definition of the centerline of a low-loss elbow.

[0031] Wherein: 1-blade suction surface, 2-blade pressure surface, 3-suction surface pressure sensing hole, 4-front edge point pressure sensing hole, 5-pressure surface pressure sensing hole, 6-pressure channel, 7-low-loss elbow, 8-handle boss, 9-handle, 10-pressure pipe interface, 11-5% length point of primitive level center arc line starting from primitive level front edge point, 12-primitive level front edge point, 13-primitive level center arc line, 14-blade profile inscribed circle, 15-1 / 3 blade thickness, 16-primitive level trailing edge point, 17-30% length point of primitive level center arc line starting from primitive level front edge point, 18-30% length point of another primitive level center arc line starting from primitive level front edge point. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Embodiment 1

[0034] like Figure 1 and Figure 2 As shown, this embodiment introduces a handle-type blade with three pressure-sensing holes at the leading edge of the primitive 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 elbow (7), a handle boss (8), a handle (9), and a pressure-inducing pipe interface (10). 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 primitive 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 (10), and the length of the pressure-inducing pipe interface is 20 mm and the diameter is 0.8 mm.

[0035] Figure 3 is a primitive level in the leaf of the present invention, Figure 5It is a primitive level at the blade root of the present invention; Figure 3 , the center line of the leading edge point pressure sensing hole (4) coincides with the tangent line of the middle arc line of the elementary level 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 middle arc line from the elementary level leading edge point to the 5% length point (11), 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 middle arc line from the elementary level leading edge point to the 5% length point (11); Figure 3 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 5 Starting from the handle, the pressure-inducing channels (6) behind the first to fifth rows of leading edge pressure sensing holes (4) are bent toward the handle (9) at the points of 30%, 35%, 40%, 45% and 50% of the mid-arc length from the leading edge of the blade, respectively, and low-loss elbows (7) are used at the bends; Fig.12 , 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 θ value 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.

[0036] Figure 6 The invention shows the position where the pressure-inducing channel (6) connecting the pressure-sensing holes of the suction surface and the pressure surface bends toward the handle (9) on the primitive level; the primitive level inscribed circle (14) at the 2% arc length behind the bending point of the pressure-inducing channel (8) connecting the leading edge point pressure-sensing hole (4) is taken, and on the line connecting the tangent points of the circle with the suction surface (1) and the pressure surface (2), points 1 / 3 of the blade thickness (15) of the suction surface (1) and the pressure surface (2) are taken respectively, and these two points are respectively used as the bending points of the pressure-inducing channel connecting the pressure-sensing holes of the suction surface and the pressure surface; the pressure-inducing channel (6) connecting the pressure-sensing holes of the suction surface and the pressure surface bends toward the handle (9) at these two points, and the bending part adopts a low-loss elbow (7) design, and the pressure-inducing channel (6) after bending is a straight channel.

[0037] The blade is mounted on the wheel hub via the handle boss (8) and the handle (9), and the pressure-conducting pipe is connected to the pressure-conducting pipe interface (10) in the handle (9) and is led out through the opening on the wheel hub.

[0038] Embodiment 2

[0039] like Figure 7 and Figure 8As shown, this embodiment introduces a handle-type blade with three pressure-sensing holes at the leading edge of the primitive 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 elbow (7), a handle boss (8), a handle (9), and a pressure-inducing pipe interface (10). 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 primitive 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 holes, that is, 0.4 mm; one end of the pressure-inducing channel (8) is connected to the orifice of the pressure sensing hole, and the other end is connected to the pressure-inducing pipe interface (10), and the length of the pressure-inducing pipe interface is 10 mm and the diameter is 0.8 mm.

[0040] Figure 3 is a primitive level in the leaf of the present invention, Figure 5 It is a primitive level at the blade root of the present invention; Figure 3 , the center line of the leading edge point pressure sensing hole (4) coincides with the tangent line of the middle arc line of the elementary level 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 middle arc line from the elementary level leading edge point to the 5% length point (11), 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 middle arc line from the elementary level leading edge point to the 5% length point (11); Figure 3 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 5 Starting from the handle, the pressure-inducing channels (6) behind the first to fifth rows of leading edge pressure sensing holes (4) are bent toward the handle (9) at the points of 30%, 35%, 40%, 45% and 50% of the mid-arc length from the leading edge of the blade, respectively, and low-loss elbows (7) are used at the bends; Fig.12 , 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 θ value 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.

[0041] Figure 6The position where the pressure-inducing channel (6) connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the handle (9) on the primitive level is indicated; the primitive level inscribed circle (14) at the length of the middle arc 2% behind the bending point of the pressure-inducing channel (8) connecting the leading edge point pressure-sensing holes (4) is taken, and on the line connecting the tangent points of the circle with the suction surface (1) and the pressure surface (2), points 1 / 3 of the blade thickness (15) from the suction surface (1) and the pressure surface (2) are taken respectively, and these two points are respectively used 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 (6) connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the handle (9) at these two points, and the bending parts are designed with low-loss elbows (7).

[0042] Fig. 9 yes Figure 7 The main view and partial section are shown. Fig.11 Schematic diagram of the position of the center line of the pressure-inducing channel (6) inside the twisted blade after it is bent toward the handle (9); due to the twisting of the blade, the pressure-inducing channel cannot reach the end of the handle (9) in the form of a straight channel after being bent 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.11 Taking the two blade primitive levels in the example, if the pressure-inducing channel (6) bends at the point (17) 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 point (18) where the arc line of all primitive levels below the primitive level is 30% of the length starting from the leading edge point of the primitive level coincide with each other.

[0043] The blade is mounted on the wheel hub via the handle boss (8) and the handle (9), and the pressure-conducting pipe is connected to the pressure-conducting pipe interface (10) in the handle (9) and is led out through the opening on the wheel hub.

[0044] Embodiment 3

[0045] like Figure 1 and Figure 2As shown, this embodiment introduces a handle-type blade with three pressure-sensing holes at the leading edge of the primitive 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 elbow (7), a handle boss (8), a handle (9), and a pressure-inducing pipe interface (10). 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 primitive 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 (10), and the length of the pressure-inducing pipe interface is 20 mm and the diameter is 0.8 mm.

[0046] Figure 3 is a primitive level in the leaf of the present invention, Figure 5 It is a primitive level at the blade root of the present invention; Figure 3 , the center line of the leading edge point pressure sensing hole (4) coincides with the tangent line of the middle arc line of the elementary level 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 middle arc line from the elementary level leading edge point to the 5% length point (11), 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 middle arc line from the elementary level leading edge point to the 5% length point (11); Figure 3 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 5 Starting from the handle, the pressure-inducing channels (6) behind the first to fifth rows of leading edge pressure sensing holes (4) are bent toward the handle (9) at the points of 30%, 35%, 40%, 45% and 50% of the mid-arc length from the leading edge of the blade, respectively, and low-loss elbows (7) are used at the bends; Fig.12 , 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 θ value 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.

[0047] Figure 6The invention shows the position where the pressure-inducing channel (6) connecting the pressure-sensing holes of the suction surface and the pressure surface bends toward the handle (9) on the primitive level; the primitive level inscribed circle (14) at the 2% arc length behind the bending point of the pressure-inducing channel (8) connecting the leading edge point pressure-sensing hole (4) is taken, and on the line connecting the tangent points of the circle with the suction surface (1) and the pressure surface (2), points 1 / 3 of the blade thickness (15) of the suction surface (1) and the pressure surface (2) are taken respectively, and these two points are respectively used as the bending points of the pressure-inducing channel connecting the pressure-sensing holes of the suction surface and the pressure surface; the pressure-inducing channel (6) connecting the pressure-sensing holes of the suction surface and the pressure surface bends toward the handle (9) at these two points, and the bending part adopts a low-loss elbow (7) design, and the pressure-inducing channel (6) after bending is a straight channel.

[0048] Fig.10 yes Fig. 9 A partial enlarged view of the middle blade handle (9); in this embodiment, the pressure-inducing channel (6) and the pressure-inducing pipe interface (10) are connected by a conical surface, and the length of this connection section is 10 mm.

[0049] The blade is mounted on the wheel hub via the handle boss (8) and the handle (9), and the pressure-conducting pipe is connected to the pressure-conducting pipe interface (10) in the handle (9) and is led out through the opening on the wheel hub.

[0050] Embodiment 4

[0051] like Figure 7 and Figure 8 As shown, this embodiment introduces a handle-type blade with three pressure-sensing holes at the leading edge of the primitive 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 elbow (7), a handle boss (8), a handle (9), and a pressure-inducing pipe interface (10). 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 primitive 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 holes, that is, 0.4 mm; one end of the pressure-inducing channel (8) is connected to the orifice of the pressure sensing hole, and the other end is connected to the pressure-inducing pipe interface (10), and the length of the pressure-inducing pipe interface is 10 mm and the diameter is 0.8 mm.

[0052] Figure 3 is a primitive level in the leaf of the present invention, Figure 5 It is a primitive level at the blade root of the present invention; Figure 3, the center line of the leading edge point pressure sensing hole (4) coincides with the tangent line of the middle arc line of the elementary level 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 middle arc line from the elementary level leading edge point to the 5% length point (11), 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 middle arc line from the elementary level leading edge point to the 5% length point (11); Figure 3 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 5 Starting from the handle, the pressure-inducing channels (6) behind the first to fifth rows of leading edge pressure sensing holes (4) are bent toward the handle (9) at the points of 30%, 35%, 40%, 45% and 50% of the mid-arc length from the leading edge of the blade, respectively, and low-loss elbows (7) are used at the bends; Fig.12 , 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 θ value 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.

[0053] Figure 6 The position where the pressure-inducing channel (6) connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the handle (9) on the primitive level is indicated; the primitive level inscribed circle (14) at the length of the middle arc 2% behind the bending point of the pressure-inducing channel (8) connecting the leading edge point pressure-sensing holes (4) is taken, and on the line connecting the tangent points of the circle with the suction surface (1) and the pressure surface (2), points 1 / 3 of the blade thickness (15) from the suction surface (1) and the pressure surface (2) are taken respectively, and these two points are respectively used 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 (6) connecting the pressure-sensing holes on the suction surface and the pressure surface bends toward the handle (9) at these two points, and the bending parts are designed with low-loss elbows (7).

[0054] Fig. 9 yes Figure 7 The main view and partial section are shown. Fig.11 Schematic diagram of the position of the center line of the pressure-inducing channel (6) inside the twisted blade after it is bent toward the handle (9); due to the twisting of the blade, the pressure-inducing channel cannot reach the end of the handle (9) in the form of a straight channel after being bent 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.11Taking the two blade primitive levels in the example, if the pressure-inducing channel (6) bends at the point (17) 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 point (18) where the arc line of all primitive levels below the primitive level is 30% of the length starting from the leading edge point of the primitive level coincide with each other.

[0055] Fig.10 yes Fig. 9 A partial enlarged view of the middle blade handle; in this embodiment, the pressure-inducing channel (6) and the pressure-inducing tube interface (10) are connected by a conical surface, and the length of this connection section is 5 mm.

[0056] The blade is mounted on the wheel hub via the handle boss (8) and the handle (9), and the pressure-conducting pipe is connected to the pressure-conducting pipe interface (10) in the handle (9) and is led out through the opening on the wheel hub.

Claims

1. A handle-type 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 handle boss (8), a handle (9), and a pressure induction pipe interface (10); 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 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 are at the leading edge. The tangent lines at the point coincide with each other, the center line of the pressure sensing hole (3) on the suction surface is the normal line of the suction surface at a point where the length of the mid-arc line of the elementary stage is 0.5% to 20% from the elementary stage front edge point, and the center line of the pressure sensing hole (5) on the pressure surface is the normal line of the pressure surface at a point where the length of the mid-arc line of the elementary stage is 0.5% to 20% from the elementary stage front edge point; 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 (10) located in the handle (9); 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 elementary stage of the blade to the trailing edge of the blade, and bends toward the handle (9) at a point where the length of the mid-arc line is 30% to 50% from the elementary stage front edge point, 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 (10) 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; the pressure tube is connected to the pressure tube interface (10) in the handle (9) and then led out through the opening on the hub; 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.

Images