CN113280994B - Low-pressure turbine wake sweeping device capable of accurately simulating state of incoming flow boundary layer - Google Patents
Low-pressure turbine wake sweeping device capable of accurately simulating state of incoming flow boundary layer Download PDFInfo
- Publication number
- CN113280994B CN113280994B CN202110659074.6A CN202110659074A CN113280994B CN 113280994 B CN113280994 B CN 113280994B CN 202110659074 A CN202110659074 A CN 202110659074A CN 113280994 B CN113280994 B CN 113280994B
- Authority
- CN
- China
- Prior art keywords
- plate
- boundary layer
- pressure turbine
- flow
- low
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
- G01M9/02—Wind tunnels
- G01M9/04—Details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M15/00—Testing of engines
- G01M15/02—Details or accessories of testing apparatus
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M15/00—Testing of engines
- G01M15/14—Testing gas-turbine engines or jet-propulsion engines
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
Abstract
The invention provides a low-pressure turbine wake sweeping device for accurately simulating the state of an incoming flow boundary layer, wherein a whole cascade test section flow channel can be divided into two flow channels by utilizing a flat plate, a larger main flow channel is used for developing the flow research of a cascade, and a smaller flow channel is a bypass flow channel; the radial relative position of the front plate and the rear plate is adopted to realize the change of the condition of the inlet boundary layer; a partition plate is additionally arranged at the rear edges of the front plate and the rear plate, so that the influence of vortex shedding of the trailing edge is greatly reduced.
Description
Technical Field
The invention relates to the technical field of precise test and testing of gas turbine engine impeller machinery, in particular to a low-pressure turbine wake sweeping device for precisely simulating the state of an incoming flow boundary layer.
Background
High load, low pressure turbines are commonly used in modern gas turbine engines for the purpose of improving fuel economy and the like. The high load design of the blade generates high reverse pressure gradient in the blade passage, and directly causes the secondary flow in the turbine end area to be increased obviously. Research has shown that the secondary flow loss of the high-load low-pressure turbine accounts for 30% of the total loss, and the efficiency of the low-pressure turbine is significantly affected. The high-precision numerical simulation research reveals two main high-loss generation rate areas of secondary flow loss of the high-load low-pressure turbine, namely an angular vortex area near an end wall and a reverse vortex area generated by interaction of a channel vortex and a blade suction surface. At the same time, studies have also found that the development of secondary flows in the tip region and their corresponding loss generation depends on various factors, such as blade loading, unsteady oncoming flow, and oncoming flow boundary layer conditions. Wherein, the blade load, including the load size and distribution, can be realized by blade profile design; unsteady incoming flows may also be achieved by wake sweeps, as shown in FIG. 1. The incoming flow boundary layer is typically achieved by boundary layer suction or by using Boundary Layer Simulators (BLS). However, due to the negative pressure gradient between the interior of the cascade wind tunnel and the ambient pressure, the wake sweep causes the end walls to present gaps in which leakage flows can form (shown in fig. 1). Although the leakage flow does not affect the quality of the main flow field of the cascade wind tunnel, the leakage flow plays a role in pumping an end wall boundary layer. Therefore, a new boundary layer is formed at the downstream of the gap, and the boundary layer is superposed with the residual part of the inlet end wall flow disturbed by the wake sweeping rod, so that the inlet boundary layer flowing into the low-pressure turbine is full of uncertainty, the state of the boundary layer cannot be accurately judged, the influence of the inlet boundary layer on the flow of the turbine end region under the abnormal condition of wake sweeping cannot be accurately carried out, and the establishment of a low-pressure turbine accurate test database is greatly limited.
Disclosure of Invention
In order to accurately simulate the state of an incoming flow boundary layer, the invention provides a low-pressure turbine wake sweeping device for accurately simulating the state of the incoming flow boundary layer.
A low pressure turbine wake sweep apparatus that accurately simulates incoming flow boundary layer conditions, comprising: the device comprises a wind tunnel test section flow channel, blades, a flat plate, a blade grid end wall and a sweep bar;
placing a flat plate in a flow channel of a wind tunnel test section to serve as an end wall of one side of a low-pressure turbine blade cascade, and keeping the end wall of the other side of the low-pressure turbine blade cascade unchanged if the end wall of the other side of the low-pressure turbine blade cascade is not changed;
the flat plate can divide the whole flow passage of the cascade wind tunnel test section into two parts, wherein, a larger main passage is used for developing the flow research of the low-pressure turbine cascade, a smaller flow passage is a bypass passage,
the flat plate is divided into two parts, one is an upstream front plate, the other is a downstream rear plate, and a gap is formed between the upstream front plate and the downstream rear plate;
the upstream front plate and the downstream rear plate are both 2 times the diameter (d) of the sweep bar, or 8% of the chord length (C) of the blade, and are provided with a super-elliptical leading edge, and the geometry is the following equation:
a baffle is provided at the trailing edges of the upstream front plate and the downstream back plate, the baffle having a length (lsp) of 3 times the sweep rod diameter (d) and a thickness (dsp) of 0.25 times the sweep rod diameter.
Preferably, the changing of the inlet boundary layer conditions is achieved by adjusting the radial position of the upstream front plate up and down, keeping the downstream back plate position constant.
Preferably, a temperature sensor is arranged in the flow channel of the cascade wind tunnel test section.
Preferably, the temperature sensor is a Pt temperature sensor.
Preferably, the sweep bar is disposed vertically between the upstream front plate and the downstream back plate.
The invention provides a low-pressure turbine wake sweeping device for accurately simulating the state of an incoming flow boundary layer, which has the following advantages:
1) The whole flow channel of the blade grid test section can be divided into two flow channels by utilizing a flat plate, a larger main flow channel is used for developing blade grid flow research, and a smaller flow channel is a bypass flow channel.
2) The changing of the inlet boundary layer conditions is achieved by the relative radial position of the front and rear plates.
3) A partition plate is additionally arranged at the rear edges of the front plate and the rear plate, so that the influence of vortex shedding of the trailing edge is greatly reduced.
Drawings
FIG. 1 is a schematic diagram of a conventional wake sweeping apparatus of the prior art.
FIG. 2 is a schematic structural diagram of a low pressure turbine wake sweep apparatus for accurately simulating the conditions of an incoming flow boundary layer in accordance with the present invention.
FIG. 3 is a schematic illustration of the boundary layer created by the rear panel aligning (Δ z = 0) the rear panel and the front panel downward Δ z = -2% C relative to the rear panel, obtained by numerical simulation of the present invention.
FIG. 4 is a graph illustrating the boundary layer conditions of the back plate at different relative positions of the front plate measured using hot wires according to the present invention.
1. Blade, 2, upstream front plate, 3, downstream back plate, 4, cascade end wall, 5, temperature sensor, 6, sweep bar, 7, upstream front plate diaphragm, 8, downstream back plate diaphragm
Detailed Description
In order that the invention may be better understood, the following further description is provided, taken in conjunction with the accompanying examples, so that the advantages and features of the invention will be more readily understood by those skilled in the art. It should be noted that the following description is only a preferred embodiment of the present invention, but the present invention is not limited to the following embodiment. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Therefore, it is intended that the present invention encompass such modifications and variations within the scope of the appended claims and their equivalents.
The invention discloses a low-pressure turbine wake sweeping device for accurately simulating the state of an incoming flow boundary layer, which comprises: the device comprises a wind tunnel test section flow channel, blades 1, a flat plate, a blade grid end wall 4 and a sweep bar 6;
placing a flat plate in a flow channel of a wind tunnel test section to serve as an end wall of one side of a low-pressure turbine blade cascade, and keeping the end wall 4 of the other side of the low-pressure turbine blade cascade unchanged;
the flat plate can divide the whole flow passage of the cascade wind tunnel test section into two parts, wherein, a larger main passage is used for developing the flow research of the low-pressure turbine cascade, a smaller flow passage is a bypass passage,
the flat plate is divided into two parts, one part is an upstream front plate 2, the other part is a downstream rear plate 3, and a gap still exists between the upstream front plate 2 and the downstream rear plate 3;
the thickness (b) of the upstream front plate 2 and the downstream back plate 3 are both 2 times the diameter (d) of the sweep bar 6, or 8% of the blade chord (C), and a super-elliptical leading edge is provided, the geometry being given by the following equation:
a baffle is provided at the trailing edges of the upstream front plate 2 and the downstream back plate 3, the baffle having a length (lsp) of 3 times the diameter (d) of the sweep rod and a thickness (dsp) of 0.25 times the diameter (d) of the sweep rod.
A temperature sensor is arranged in a runner of the cascade wind tunnel test section, and the temperature sensor is a Pt temperature sensor.
The invention provides a low-pressure turbine wake sweeping device for accurately simulating the state of an incoming flow boundary layer, which is characterized in that a flat plate is placed in a flow channel of a wind tunnel test section by combining the characteristics of a conventional wake sweeping device and is used as a new end wall at one side of a low-pressure turbine blade cascade, such as the flat plate shown in figure 2, and the end wall at the other side is kept unchanged. The inserted plate may divide the entire cascade test section flow channel into two parts. The larger main channel is used for carrying out low-pressure turbine blade cascade flow research, and the smaller flow channel is a bypass channel. The wake sweep simulator divides the inserted plate into two parts, one upstream front plate 2 and one downstream rear plate 3. There is still a gap between the upstream front plate 2 and the downstream back plate 3, resulting in an interruption of the development of the inlet boundary layer. The boundary layer thickness required by the low-pressure turbine blade cascade test is realized by overlapping the boundary layer on the rear plate and the wake region of the front plate.
Accordingly, the present invention provides an improved low pressure turbine wake sweep apparatus that accurately simulates the conditions of the incoming flow boundary layer from three points as compared to the original design. Firstly, there is a certain distance between the outer end wall of the tunnel where the leakage occurs and the plate where the boundary layer needs to be generated. Secondly, there is the flow all on dull and stereotyped both sides, has weakened the leakage influence to a certain extent. Finally, the sealing of the trailing sweep bar 6 is further improved, thereby reducing the pressure gradient with the outside. All this reduces the pressure acting on the flow between the plates considerably, thus reducing the suction effect of the boundary layer.
The upstream front plate 2 and the downstream back plate 3 each have a thickness (b) of 2 times the diameter (d) of the sweep bar 6, or 8% of the chord length (C) of the blade, and are provided with a super-elliptical leading edge with a geometry according to the following equation.
In addition, as shown in FIG. 2, the trailing edges of the upstream front plate 2 and the downstream rear plate 3 are each smaller by oneThe block partition plate can greatly reduce the falling influence of the trailing edge vortex. The upstream front plate baffle 7 ensures that the primary source of unsteady character in the inlet incoming flow is the periodic wake sweep wand flow. The downstream backplate diaphragm 8 acts to prevent trailing edge vortex shedding from affecting the pressure field in the low pressure turbine outlet measurement face. The length (lsp) of the baffle was 3 sweep rod diameters (d) and the thickness (dsp) was 0.25 sweep rod diameters. Changing the inlet boundary layer conditions is achieved by adjusting the radial position of the upstream front plate 2 up and down, keeping the downstream back plate 4 position constant. FIG. 3 shows the boundary layer created by the rear panel aligned (Δ z = 0) by the numerical simulation with the rear panel and the front panel down Δ z = -2% C relative to the rear panel. Measuring the boundary layer conditions of the rear plate at different relative positions of the front plate by using a hot wire, and using u + -y + The graph determines the boundary layer state as shown in fig. 4. Wherein, blasius distribution is laminar boundary layer, and Van Driest distribution is full turbulent boundary layer. FIG. 4 also shows the boundary layer velocity and turbulence profile. Through u + -y + Graph and boundary layer form factor (H) 12 ) The boundary layer state can be determined, and incoming flow conditions are provided for accurately developing the influence of the inlet boundary layer on the flow of the turbine end area under the unsteady condition of wake sweep.
The invention provides a low-pressure turbine wake sweeping device for accurately simulating the state of an incoming flow boundary layer, wherein a whole cascade test section flow channel can be divided into two flow channels by utilizing a flat plate, a larger main flow channel is used for developing the flow research of a cascade, and a smaller flow channel is a bypass flow channel; the condition of an inlet boundary layer is changed by adopting the radial relative positions of the front plate and the rear plate; a partition plate is additionally arranged at the rear edges of the front plate and the rear plate, so that the influence of vortex shedding of the trailing edge is greatly reduced.
All equivalent or simple changes in the structure, characteristics and principles of the invention which are described in the patent conception are included in the protection scope of the invention. Various modifications, additions and substitutions for the specific embodiments described may occur to those skilled in the art without departing from the scope of the invention as defined in the accompanying claims.
Claims (4)
1. A low pressure turbine wake sweep apparatus for accurately simulating incoming flow boundary layer conditions, comprising: the device comprises a wind tunnel test section flow channel, blades (1), a flat plate, a blade grid end wall (4) and a sweeping rod (6);
placing the flat plate in a flow channel of a wind tunnel test section to serve as an end wall of one side of a low-pressure turbine blade cascade, and keeping an end wall (4) of the other side of the blade cascade unchanged;
the flat plate can divide the whole flow passage of the cascade wind tunnel test section into two parts, wherein, a larger main passage is used for developing the flow research of the low-pressure turbine cascade, a smaller flow passage is a bypass passage,
the flat plate is divided into two parts, one part is an upstream front plate (2), the other part is a downstream rear plate (3), and a gap is formed between the upstream front plate (2) and the downstream rear plate (3);
the thickness b of the upstream front plate (2) and the downstream back plate (3) is 2 times the diameter (d) of the sweep bar (6), or 8% of the chord length (C) of the blade, and a super-elliptic front edge is arranged, and the geometrical shape is the following equation:
arranging a clapboard at the rear edges of the upstream front plate (2) and the downstream back plate (3), wherein the length (lsp) of the clapboard is 3 times of the diameter (d) of the sweep rod, and the thickness (dsp) of the clapboard is 0.25 times of the diameter of the sweep rod;
the sweep rod (6) is vertically arranged between the upstream front plate (2) and the downstream back plate (3).
2. A low pressure turbine wake swept device for accurately simulating oncoming flow boundary layer conditions as claimed in claim 1 wherein the inlet boundary layer conditions are varied by adjusting the radial position of the upstream forward plate (2) up and down, keeping the downstream aft plate (3) position constant.
3. The low-pressure turbine wake sweeping device for accurately simulating the state of an incoming flow boundary layer according to claim 2 is characterized in that a temperature sensor (5) is arranged in a flow channel of a wind tunnel test section.
4. A low pressure turbine wake swept device accurately simulating oncoming flow boundary layer conditions, as claimed in claim 3, characterized in that the temperature sensor (5) is a Pt temperature sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110659074.6A CN113280994B (en) | 2021-06-15 | 2021-06-15 | Low-pressure turbine wake sweeping device capable of accurately simulating state of incoming flow boundary layer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110659074.6A CN113280994B (en) | 2021-06-15 | 2021-06-15 | Low-pressure turbine wake sweeping device capable of accurately simulating state of incoming flow boundary layer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113280994A CN113280994A (en) | 2021-08-20 |
| CN113280994B true CN113280994B (en) | 2022-12-27 |
Family
ID=77284390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110659074.6A Active CN113280994B (en) | 2021-06-15 | 2021-06-15 | Low-pressure turbine wake sweeping device capable of accurately simulating state of incoming flow boundary layer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113280994B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116499686B (en) * | 2023-06-29 | 2023-08-22 | 中国航空工业集团公司沈阳空气动力研究所 | Ground high-speed ejection simulation system and simulation method for wind tunnel test |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6993311B2 (en) * | 2018-09-21 | 2022-01-13 | 三菱重工業株式会社 | Boundary layer control device and wind tunnel test device |
| CN111929026B (en) * | 2020-09-29 | 2020-12-15 | 中国空气动力研究与发展中心低速空气动力研究所 | Low-frequency pressure pulsation suppression method for wind tunnel 3/4 opening test section |
| CN112179671B (en) * | 2020-09-30 | 2022-10-21 | 中国科学院工程热物理研究所 | Low-pressure turbine annular blade cascade test bed with unsteady wake simulation function |
| CN112729751B (en) * | 2020-12-30 | 2023-10-27 | 哈尔滨工业大学 | Test bed |
-
2021
- 2021-06-15 CN CN202110659074.6A patent/CN113280994B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113280994A (en) | 2021-08-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Roback et al. | Hot streaks and phantom cooling in a turbine rotor passage: Part 1—separate effects | |
| Kapteijn et al. | Aerodynamic Performance of a Transonic Turbine Guide Vane With Trailing Edge Coolant Ejection: Part I—Experimental Approach | |
| CN109506744B (en) | Air flow calibration method for venturi nozzle of aircraft engine complete machine test | |
| CN113280994B (en) | Low-pressure turbine wake sweeping device capable of accurately simulating state of incoming flow boundary layer | |
| Barigozzi et al. | Effects of injection conditions and Mach number on unsteadiness arising within coolant jets over a pressure side vane surface | |
| CN110043370B (en) | Air flow measuring method of turbofan engine core machine | |
| Hoeger et al. | Influence of endwall contouring on the transonic flow in a compressor blade | |
| Henry et al. | Summary of subsonic-diffuser data | |
| Peltier et al. | Experimental investigation of the performance of different bleed air system designs | |
| Mao et al. | Kelvin-Helmholtz and streamwise vortices in the near wake of a single-lobe forced mixer | |
| Sun et al. | Investigations on aerodynamic performance of turbine cascade at different flow conditions | |
| CN115356115A (en) | Layout method for mainstream flow field fine test in core machine environment | |
| Buffum et al. | Oscillating cascade aerodynamics at large mean incidence | |
| Hála et al. | Optimization of root section for ultra-long steam turbine rotor blade | |
| Sieverding et al. | The influence of boundary layer state on vortex shedding from flat plates and turbine cascades | |
| Gottschall et al. | Penny gap effect on performance and secondary flowfield in a compressor cascade | |
| MacMartin et al. | The aerodynamics of a turbine cascade with supersonic discharge and trailing edge blowing | |
| Lepicovsky et al. | Exploratory Experiments for Simple Approximation of Blade Flutter Aerodynamic Loading Function | |
| Gao et al. | Experimental investigation of effects of tip cavity on tip clearance flow in a variable-geometry turbine cascade | |
| Satta et al. | Wake control by boundary layer suction applied to a high-lift low-pressure turbine blade | |
| Schubert et al. | Characterization of the Endwall Flow in a Low-Pressure Turbine Cascade Perturbed by Periodically Incoming Wakes, Part 1: Flow Field Investigations with Phase-Locked Particle Image Velocimetry | |
| Kang et al. | Experimental study on the three dimensional flow within a compressor cascade with tip clearance: part I—velocity and pressure fields | |
| Krug et al. | Effects of the Steady Wake-Tip Clearance Vortex Interaction in a Compressor Cascade: Part I—Experimental Investigations | |
| Liu et al. | Numerical investigation of the effects of ITD length on low pressure nozzle | |
| Yocum II | An experimental and numerical investigation of the performance of compressor cascades with stalled flow |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |