JP3167465B2 - Apparatus for analyzing tip clearance flow of turbine blade - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for visualizing and analyzing a blade tip gap flow in a mutual gap between a blade tip of a turbine blade used for a gas turbine engine and a passage wall of a combustion gas. .

[0002]

2. Description of the Related Art A plurality of turbine blades used in a gas turbine engine or the like are implanted at intervals in a circumferential direction on an outer peripheral surface of a disk-shaped disk and are radially disposed on the outer peripheral surface of the disk. Then, the wings are arranged in a gas passage formed in a cylindrical casing, and the combustion gas flowing through the gas passage is inserted through the wings, so that the circumference of the casing is about 500 m / s. It can rotate at high speed.

[0003] In this case, in order to effectively convert the energy of the combustion gas into rotational force, it is necessary to receive the combustion gas without leakage. For this purpose, the clearance between the inner surface of the casing and the blade tip of the turbine blade is reduced to minimize the amount of combustion gas passing without giving a rotational force to the turbine blade.

The gap (tip clearance) between the inner surface of the casing and the turbine blades causes a secondary flow (blade tip clearance flow) behind the turbine blades to increase pressure loss, decrease outflow angle, and the like. It is known to invite. Since the generation of the secondary flow cannot be avoided as long as there is a gap at the blade tip, it is necessary to perform aerodynamic design of the turbine blade in which the generation of the secondary flow is positively considered.

On the other hand, in the field of numerical simulation of flow using a computer, three-dimensional viscosity analysis is entering the stage of practical use due to the development of both hardware and software of the computer. Application is desired. Then, it is necessary to collect experimental data as basic data supporting the numerical simulation.

[0006] Conventionally, in order to measure the state of flow in the tip clearance of a turbine blade, airflow is passed around a plurality of cantilevers arranged in a duct in a cantilever manner, and the blade tip of the blade is A test apparatus for realizing a flow equivalent to the flow in an actual turbine between a duct wall surface and the duct wall is configured.
Then, by disposing the pitot tube near the mutual gap between the duct wall surface and the blade tip, the total pressure at the pitot tube tip position is measured, and the pitot tube is moved in the duct to measure the pressure of each part. Therefore, a method of measuring the flow state near the tip clearance is adopted.

[0007]

However, in such a test apparatus, since the pitot tube is arranged in the airflow inside the duct, the influence of the pitot tube on the airflow cannot be ignored. There is a problem that a measurement error occurs. In addition, since the measurement by the pitot tube is performed at one point of the tip of the pitot tube, performing a pressure measurement over the entire range of the wing tip requires a great amount of measurement time, and also visualizes the state of the flow. Requires processing of the measurement data, which requires a great deal of labor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a turbine capable of performing measurement without affecting the flow in a tip clearance and directly visualizing the flow aspect. It is an object of the present invention to provide a wing tip gap flow analysis test device for a wing.

[0009]

In order to achieve the above object, the present invention provides an analytical test apparatus for analyzing a flow of combustion gas in a mutual gap between a blade tip of a turbine blade and a combustion gas passage wall, A passage wall which is arranged in an opposed state at an interval to form an air flow therebetween, and a wing piece fixed to one side of the passage wall in a cantilever shape and arranged with a gap in the other side of the passage wall A visualization fluid ejecting means for causing a visualization fluid to flow out of the wing tip of the wing piece; a window provided on the passage wall on the wing tip side of the wing piece to form a part of the passage wall; Plane light supply means for inputting plane light having a normal line substantially parallel to the chord in the longitudinal direction of the blade piece into the airflow, and converting the plane light incident by the plane light supply means in a direction along the chord. A plane light moving means for performing parallel movement, and a downstream position of the airflow on an extension of the chord It proposes arranged to tip clearance flow analysis test device of the turbine blades comprising an imaging means for imaging light reflected by visualizing fluid irradiated plane light.

[0010]

According to the blade tip gap flow analysis test apparatus of the present invention,
By forming an airflow between the opposing passage walls, a tip end gap flow equivalent to that of an actual turbine is formed in a mutual gap between the wing tip of the blade piece disposed in the airflow and the passage wall. In this state, the visualization fluid jetting means is operated to cause the visualization fluid to flow out of the blade tip, so that the visualization fluid rides on the blade tip gap flow and flows. Then, by operating the plane light supply means, plane light is incident along the longitudinal direction of the wing piece from a window formed on the passage wall on the wing tip side, and the plane light is reflected by the visualization fluid and the blade The appearance of the end gap flow will be visualized. Since the vortex and the like characterizing the tip clearance flow appear on a plane substantially perpendicular to the chord of the wing piece, the plane light is irradiated so as to have a normal parallel to the chord, thereby forming the shape of the vortex. Can be visualized. Further, by moving the plane light in the direction along the chord, the flow of the tip clearance over the entire chord of the wing piece can be visualized, and the photographing means arranged on the extension of the chord is operated. By photographing the light reflected by the visualization fluid, it is possible to record the aspect of the tip clearance flow.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a turbine blade tip gap flow analysis test apparatus according to the present invention will be described below with reference to FIGS. The analysis test apparatus 1 of the present embodiment includes a wing piece 4 fixed in a cantilever shape to one of the passage walls 2a in a duct 3 formed between the passage walls 2a and 2b arranged at parallel intervals. This is common to the conventional analysis test apparatus in that a cascade is formed by arranging a plurality of blades, and a minute gap is formed between the other passage wall 2b and the blade tip 4a of the blade piece 4. ing. However, analyzing the test apparatus 1 of this embodiment, instead of the pressure measurement by the conventional Pitot tube, in that it employs a method of directly visualizing the tip clearance flow G _1,
It is different from the conventional analysis test equipment.

The analysis test apparatus 1 of the present embodiment includes the wing piece 4
Nozzle 6 (visualizing fluid ejecting means) for ejecting water 5 containing a fluorescent agent (visualizing fluid) in the form of fine powder from the wing tip 4a of the nozzle
And a passage 2b opposed to the wing tip 4a of the wing piece 4 with a gap.
And a plane light source 8 (plane light supply) through which the plane light P enters through the glass window 7 from the wing tip 4a of the wing piece 4 along its longitudinal direction. Means) and a plane light P incident into the duct 3 by the plane light source 8
There is provided a light source moving means 9 (plane light moving means) for translating the light in the normal direction thereof, and a photographing means 10 for photographing the reflection of the visualization fluid 5 irradiated by the plane light P.

As shown in FIG. 1, the nozzle 6 has a plurality of openings at the wing tip 4a of the wing piece 4, and is connected to a visualization fluid supply source (not shown) disposed outside through a flow path 6a in the wing piece 4. The water 5 containing the fluorescent agent supplied from the visualization fluid supply source is spouted into the duct 3 from each opening in the form of fine particles.

As shown in FIG. 2, the glass window 7 is formed integrally with the passage wall 2b so as to form a part of the passage wall 2b adjacent to the blade tip 4a of the wing piece 4 with a gap therebetween. It is formed sufficiently wide with respect to the cross section of the wing piece 4 so that the plane light P described later can be irradiated over a wide area around the wing piece 4. The inner surface of the glass window 7 forms the same plane as the inner surface of the passage wall 2b, and the air flow G ₁ in the duct 3 is formed by the glass window 7.
· G ₂ is taken into consideration so as not to be disturbed.

The plane light source 8 includes, for example, an argon gas laser light source 8a and a condenser lens 8b for adjusting a light beam emitted from the argon gas laser light source 8a so as to become a plane light P. It is arranged on the extension of the wing piece 4 in the longitudinal direction facing the wing tip 4 a of the wing piece 4 with the glass 7 interposed therebetween, so that the plane light P enters the duct 3 along the longitudinal direction of the wing piece 4. Has become. At this time, the plane light P is formed at an angle having a normal line parallel to the chord 4b of the wing piece 4 as shown in FIG.

The light source moving means 9 is, for example, a linear moving mechanism comprising a linear guide 9a, a ball screw 9b, a motor 9c, etc., and the flat light source 8 is moved on a slider 9d which is moved along the linear guide 9a. It is designed to be attached. The straight guide 9a is attached to the wing tip 4 of the wing piece 4.
The plane light source 8 is arranged so as to be parallel to a, and moves in a direction along the chord 4b.

The photographing means 10 is, for example, a video camera, and is on an extension of the chord 4b of the wing piece 4,
Located downstream position of the airflow G _2, is caused to face the orthogonal state relative to the plane light P. Thereby, the aspect of the visualization fluid 5 irradiated with the plane light P can be accurately and continuously photographed.

In order to visualize the tip clearance flow G ₁ using the analytical test apparatus 1 configured as described above, a direction perpendicular to the cascade (from below to above in FIG. 1) is set in the duct 3. to generate the airflow G _2, to achieve a comparable tip clearance flow G ₁ as in actual turbine. Then, the visualization fluid 5 is ejected from the nozzle 6 of the wing tip 4a in a fine powder state. Thus, the movable visualization fluid 5 is caused to flow in the duct 3 on wings end gap flow G _1. Then, if a vortex is generated in the wake of the wing tip 4a, the visualization fluid 5 is circulated in the form of the vortex.

[0019] The vortex, when a part of the airflow G ₂ flowing along the surface of the wing 4 flows beyond the tip 4a, are those caused by peeling in the wake of the blade tip 4a , direction orthogonal to the airflow G ₂ flowing along the surface of the wing 4, i.e., to be formed in a plane perpendicular to the schematic chord 4b. Further, even if the vortex does not occur, the direction of the streamlines of the tip clearance flow G ₁ is directed in a direction orthogonal to outline chord 4b.

The direction along this streamline, that is,
By arranging the planar light P to be perpendicular to the chord 4b, it is illuminated plane light P to visualize fluid 5 fluorescer emits light that is allowed to flow along the tip clearance flow G _1, the wing aspects of the flow is to be visualized in the leading line position of the end gap flow G _1. The aspect of the tip clearance flow G ₁ visualized in this way is photographed by the photographing means 10 and recorded.

By operating the light source moving means 9, the plane light source 8 is moved in the direction along the chord 4b,
With aspects of tip clearance flow G ₁ in the position of the different flow lines are sequentially visualized, are photographed continuously by the shooting means 10, it will be recorded.

Therefore, according to the analytical test apparatus 1 of the present embodiment, when recording the aspect of the blade tip gap flow G ₁ , no member that disturbs the air flows G ₁ and G ₂ such as the pitot tube is disposed in the duct 3. , Accurate data can be collected. Further, by processing the pressure data, the tip clearance flow G _{1 can be obtained.}
Since the analysis is performed by not visualizing the aspect but directly visualizing it, it is possible to reduce the labor required for data processing and to shorten the measurement time required for data collection.

The following technology can be adopted in the turbine blade tip gap flow analysis test apparatus 1 of the present invention. Although the plane light source 8 is constituted by the argon gas laser 8a and the condenser lens 8b, instead of this,
Adopt any light source that can constitute the plane light P. The light source moving means 9 includes a linear guide 9a, a ball screw 9
(b) Although the linear movement mechanism includes the motor 9c and the like, other actuators may be used instead. The light source moving means 9 is a linear moving mechanism for moving the plane light source 8, but instead the plane light source 8 is fixed and the plane light P itself is moved. Although the photographing means 10 is a video camera, a photographing means such as a still camera may be used instead. The plane light P is arranged so as to be orthogonal to the chord. Although the visualization fluid 5 is water containing a fluorescent agent, any other fluid may be used instead. Although the window portion 7 is a glass window, it may be made of any material that transmits plane light instead.

[0024]

As described in detail above, the turbine blade tip gap flow analysis test apparatus according to the present invention is fixed in a cantilever shape on one side of the opposing passage wall and is connected to the other side of the passage wall. Wing pieces arranged with a gap, visualization fluid jetting means for allowing the visualization fluid to flow out from the wing tip, windows provided on the passage wall on the wing tip side, and a longitudinal direction of the wing piece from outside. Plane light supply means for projecting plane light having a normal line substantially parallel to the chord, plane light moving means for translating the incident plane light in a direction along the chord, and a downstream position on an extension of the chord And a photographing means for photographing reflected light of the illuminated plane light by the visualization fluid, and has the following effects. Since the blade tip gap flow is visualized by the plane light and the visualization fluid and recorded by the photographing means, an accurate flow profile can be recorded without disposing a member that disturbs the air flow in the air flow. Rather than analyzing the flow of the tip clearance by processing the pressure data, the analysis is performed by directly visualizing the flow, so that the labor required for processing the data can be reduced. Since the flow located on the plane is visualized at a time by the plane light, the measurement time required for collecting data can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing one embodiment of a blade tip gap flow analysis test apparatus of a turbine blade according to the present invention.

FIG. 2 is a view of a blade piece viewed from a downstream side of an airflow in one embodiment of the analysis test apparatus of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Analysis test apparatus (wing tip gap flow analysis test apparatus) 2a ・ 2b Passage wall 3 Duct 4 Blade piece 4a Blade tip 4b chord 5 Fluorescent agent-containing water (visualization fluid) 6 Nozzle (visualization fluid ejection means) 6a Flow Path 7 Glass window (window portion) 8 Planar light source (flat light supply means) 8a Argon gas laser light source 8b Condensing lens 9 Light source moving means (flat light moving means) 9a Linear guide 9b Ball screw 9c Motor 9d Slider 10 Imaging means G ₁ Air flow (tip gap flow) G ₂ Air flow P Plane light

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 9/06

Claims (1)

(57) [Claims] 1. An analysis test apparatus for analyzing a flow of combustion gas in a mutual gap between a blade tip of a turbine blade and a combustion gas passage wall, wherein the passage is spaced apart and opposed to each other to form an airflow therebetween. A wall, a wing piece fixed to one side of the passage wall in a cantilever shape and disposed with a gap in the other side wall, and a visualization fluid for allowing a visualization fluid to flow out from a wing tip of the wing piece Jetting means, a window portion provided on the passage wall on the wing tip side of the wing piece and forming a part of the passage wall, and a normal passing through the window portion and substantially parallel to the chord in the longitudinal direction of the wing piece. Plane light supply means for causing plane light to enter the airflow, plane light movement means for translating the plane light incident by the plane light supply means in a direction along the chord, and on an extension of the chord. The reflected light by the visualization fluid of the illuminated plane light which is disposed at the downstream position of the airflow and A blade tip gap flow analysis test apparatus for a turbine blade, comprising: a photographing means for photographing.