A blade profile suitable for a shrouded compressor rotor

Abstract

The application belongs to the technical field of aero-engines, and particularly relates to a blade profile suitable for a band hoop compressor rotor, which comprises an inner channel main fan connected to a blade hub, a splitter ring circumferentially connected to a blade tip of the inner channel main fan, and outer channel FLADE blades circumferentially installed on an outer surface of the splitter ring; an axial chord length is divided into multiple sections, an L1 section bears 10% of a camber line bending angle change, an L2 section bears 5%-10% of the camber line bending angle change, an L3 section bears 30%-35% of the camber line bending angle change, and an L4 section bears 50% of the camber line bending angle change; the compressor rotor tip blade profile designed by using the given camber line and thickness distribution can effectively avoid premature flow separation at a blade back of the rotor band hoop and performance attenuation caused by the flow separation, and realizes higher efficiency and surge margin of the compressor under the structural layout.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of aero-engines, and particularly relates to a blade profile suitable for a hoop compressor rotor. BACKGROUND

[0002] In an axial compressor, in order to avoid the rubbing between the rotor tip and the casing, a certain radial gap is required between the rotor tip and the casing. However, the existence of the tip radial gap will produce a "secondary flow" from the leading edge to the trailing edge and from the pressure surface to the suction surface, resulting in a leakage loss and affecting the aerodynamic performance of the compressor. Therefore, in order to avoid the influence of the gap, designers try to add a ring (hoop) at the tip of the rotor, which rotates with the rotor, thus eliminating the radial gap, but the performance is not very good. Research shows that when the tip gap exists, the gas kinetic energy on the pressure surface is high, and the pressure is large, which has the ability to delay or reduce the flow separation on the suction surface, and in addition, the vortex generated by the gap flow also has the effect of inhibiting the passage vortex, so reducing the tip gap is beneficial to the performance improvement of the compressor, but eliminating the gap may bring performance degradation. Therefore, designers have not continued to carry out research work on the hoop compressor rotor.

[0003] With the development of adaptive cycle engines, the fan with FLADE (tip fan) is widely studied as an important structure form for adaptive engines to realize the addition of the bypass. The inner bypass main fan rotor blades and the outer bypass FLADE blades also adopt a ring-shaped structure connection, and the inner bypass main fan rotor does not have a tip gap. Research shows that after adding a ring-shaped flow separation structure and FLADE blades to the existing compressor, the inner bypass main fan also shows performance degradation. Therefore, the performance maintenance / improvement of the hoop rear compressor rotor becomes an important content of the performance design of the FLADE configuration fan.

[0004] By means of numerical simulation, the performance change of a certain compressor after eliminating the rotor tip gap and adding a flow separation ring (hoop) integrated with the blade and rotating simultaneously is verified. After the hoop, the pressure increasing capacity and efficiency of the compressor are greatly degraded, and the highest pressure ratio is reduced by 5.2%, and the highest efficiency is reduced by 3 percentage points.

[0005] Obvious flow separation occurs on the suction side behind the passage shock wave, and continuously intensifies with the development of the flow.

[0006] After the rotor is provided with the hoop, the change of the tip speed triangle and the tip suction separation caused by the boundary layer accumulation are the main reasons for the performance degradation. In order to improve the tip flow, the present application proposes a blade profile suitable for the tip of the hoop compressor rotor to realize the performance maintenance of the rotor with the hoop. SUMMARY

[0007] To address the aforementioned problems, this application provides an airfoil suitable for a compressor rotor with a clamp, including...

[0008] The inner main fan is connected to the blade hub, the circumferentially connected flow ring is connected to the blade tip of the inner main fan, and the outer FLADE blades are circumferentially mounted on the outer surface of the flow ring.

[0009] The relationship between the chord length and the mid-curve bend angle of the outer duct FLADE blade is as follows:

[0010] f(x) = 3.945x 6 -7.079x 5 +1.106x 4 +5.721x 3 -3.601x 2 +0.914x -0.003;

[0011] Where x is the relative chord length; f(x) is the mid-arc curvature angle;

[0012] The relationship between the chord length and thickness of the ductile FLADE blade is as follows:

[0013] g(x) front segment = 6.4336x 4 - 9.3913x 3 + 1.3856x 2 + 2.8275x + 5E-05;

[0014] g(x) -21.119x 4 + 60.853x 3 - 69.303x 2 +35.105x -5.5358;

[0015] The first part of g(x) represents the thickness before the thickness reaches its maximum point, and the second part represents the thickness after the thickness reaches its maximum point.

[0016] Preferably, the axial chord length is divided into multiple segments, including segment L1 accounting for 0-30% of the axial chord length; segment L2 accounting for 30%-50% of the axial chord length; segment L3 accounting for 50%-80% of the axial chord length; and segment L4 accounting for 80%-100% of the axial chord length. Among these segments, segment L1 accounts for 10% of the mid-arc bend angle curvature variation; segment L2 accounts for 5%-10% of the mid-arc bend angle curvature variation; segment L3 accounts for 30%-35% of the mid-arc bend angle curvature variation; and segment L4 accounts for 50% of the mid-arc bend angle curvature variation.

[0017] Preferably, the blade profile of the compressor rotor with hoops has an inlet blade tip relative Mach number between 1.1 and 1.3.

[0018] Preferably, the maximum thickness of the outer duct FLADE blade is located at 0.55 of the relative chord length.

[0019] Preferably, both the first and second parts of g(x) conform to the quartic curve pattern.

[0020] The advantages of this application include: the compressor rotor tip blade profile designed with the given mid-arc line and thickness distribution in this application concentrates the airflow deflection in the expansion section after the maximum thickness position and the shock wave in the channel, which can effectively avoid premature flow separation at the blade back after the rotor is fitted with a hoop and the resulting performance degradation, thus achieving higher efficiency and surge margin of the compressor under this structural layout. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a fan rotor with a Flade.

[0022] Figure 2 Distribution diagram of the arc angle in the leaf shape;

[0023] Figure 3 Leaf thickness distribution diagram;

[0024] Figure 4 Flow field at the tip of a conventional compressor rotor with clamps;

[0025] Figure 5 The flow field at the rotor tip after adopting the blade shape of this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0027] This application presents an airfoil for the tip of a compressor rotor with a clamping system, suitable for inlet blade tip relative Mach numbers between 1.1 and 1.3. It provides the mid-curve curve and blade thickness distribution law, which can effectively suppress the premature flow separation on the blade back after the clearance is removed and the resulting performance degradation, thus achieving performance maintenance after the rotor is clamped.

[0028] It includes the curvature of the leaf shape and the characteristics of leaf thickness distribution. The detailed technical solution is as follows:

[0029] 1. Leaf-shaped mid-curve

[0030] The blades include an inner main fan 3 connected to the hub, a flow divider ring 2 circumferentially connected to the blade tips of the inner main fan 3, and an outer bypass FLAD blade 1 circumferentially mounted on the outer surface of the flow divider ring 2, such as... Figure 1 As shown;

[0031] The distribution of the arc angle in the blade shape of the FLADE 1 duct is as follows: Figure 2 As shown:

[0032] The characteristics of the curvature distribution of the above-mentioned airfoil are as follows:

[0033] a) Section L1: 0-30% of the axial chord length bears approximately 10% of the curvature variation;

[0034] b) L2 segment: 30%-50% of the axial chord length bears about 5%-10% of the curvature change;

[0035] c) L3 segment: 50%-80% of the axial chord length bears about 30%-35% of the curvature change;

[0036] d) L4 segment: 80%-100% of the axial chord length bears about 50% of the curvature variation;

[0037] The parameterized expression for the arc angle distribution in the above airfoil is:

[0038] f(x) = 3.945x 6 -7.079x 5 +1.106x 4 +5.721x 3 -3.601x 2 +0.914x-0.003

[0039] 2. Leaf thickness distribution

[0040] In conjunction with the above-mentioned mid-curve of the blade shape, the blade thickness distribution given in this patent is as follows: Figure 3 As shown:

[0041] The maximum thickness of the blade is located at 0.55 of the relative chord length. Taking this maximum thickness position as the dividing point, the thickness distribution is divided into two segments, both of which conform to a quartic curve. The parameterized expression for this is:

[0042] g(x) front segment = 6.4336x 4 - 9.3913x 3 + 1.3856x 2 + 2.8275x + 5E-05;

[0043] g(x) -21.119x 4 + 60.853x 3 - 69.303x 2 +35.105x -5.5358;

[0044] 3. The implementation effect of the leaf shape of the present invention

[0045] The static pressure distribution on the blade surface of a compressor rotor with a hoop is as follows: Figure 4 As shown, significant flow separation occurred on the blade back, affecting the pressurization capability of the rotor tip.

[0046] The static pressure distribution on the airfoil surface after redesigning airfoils with over 80% of the airfoil height using the arc and thickness distribution proposed in this patent is as follows: Figure 5 As shown, the flow separation phenomenon at the leaf tip has been effectively improved, and the pressurization capacity on the leaf back has been significantly enhanced.

[0047] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An airfoil suitable for a compressor rotor with a hoop, characterized in that, include The inner main fan (3) is connected to the blade hub, the circumferentially connected to the blade tip of the inner main fan (3) is the flow-splitting ring (2), and the outer FLADE blade (1) is circumferentially installed on the outer surface of the flow-splitting ring (2). The relationship between the chord length and the mid-curve bend angle of the outer FLADE blade (1) is as follows: f(x)=3.945x 6 -7.079x 5 +1.106x 4 +5.721x 3 -3.601x 2 +0.914x-0.003; Where x is the relative chord length; f(x) is the mid-arc curvature angle. The relationship between the chord length and thickness of the ferrule blade (1) is as follows: g(x) front segment = 6.4336x 4 - 9.3913x 3 + 1.3856x 2 + 2.8275x + 5E-05; g(x) -21.119x 4 + 60.853x 3 - 69.303x 2 +35.105x -5.5358; The first part of g(x) represents the thickness before the thickness reaches its maximum point, and the second part represents the thickness after the thickness reaches its maximum point.

2. The blade profile for a compressor rotor with a hoop as described in claim 1, characterized in that, The axial chord length is divided into multiple segments, including segment L1, which accounts for 0-30% of the axial chord length; segment L2, which accounts for 30%-50% of the axial chord length; segment L3, which accounts for 50%-80% of the axial chord length; and segment L4, which accounts for 80%-100% of the axial chord length. Among them, segment L1 accounts for 10% of the camber of the middle arc; segment L2 accounts for 5%-10% of the camber of the middle arc; segment L3 accounts for 30%-35% of the camber of the middle arc; and segment L4 accounts for 50% of the camber of the middle arc.

3. The blade profile for a compressor rotor with a hoop as described in claim 1, characterized in that, The blade profile of the compressor rotor with hoops is located at the inlet blade tip relative Mach number between 1.1 and 1.

3.

4. The blade profile for a compressor rotor with a hoop as described in claim 1, characterized in that, The maximum thickness of the outer duct FLADE blade (1) is located at 0.55 of the relative chord length.

5. The blade profile for a compressor rotor with a hoop as described in claim 1, characterized in that, Both the first and second parts of g(x) conform to the quartic curve pattern.

Images