CN-115374566-B - Method for realizing optimal fluidity of sealing cavity of comb teeth of axial flow compressor

Abstract

A method for realizing optimized fluidity of a comb seal cavity of an axial-flow compressor includes dividing the inside of the comb seal cavity into a flow control area and a speed field matching area according to flow characteristics in the comb seal cavity, designing optimized geometry of a static upper end wall of the comb seal cavity by combining practical engineering constraint, carrying out flow analysis on the optimized geometry through CFD numerical simulation calculation, and evaluating performance influence of the optimized geometry on stator blades. According to the invention, through analyzing the flow characteristics in the sealing cavity of the comb teeth, the inside of the sealing cavity is partitioned, and the mobility of each area is designed in a targeted manner, so that the optimized geometric structure is obtained, and the aims of reducing the total pressure loss of the stator blade and improving the supercharging capacity of the stator blade are fulfilled.

Inventors

• Zheng Biaojia
• Shao Runzhu
• TENG JINFANG
• Deng Hefang
• ZHU MINGMIN
• QIANG XIAOQING

Assignees

• 上海交通大学
• 上海交通大学

Dates

Publication Date

20260421

Application Date

20220901

Priority Date

20220901

Claims (4)

1. 1. A realization method for optimizing mobility of a comb seal cavity of an axial flow compressor is characterized by dividing the interior of the comb seal cavity into a flow control area and a speed field matching area according to flow characteristics in the comb seal cavity, then designing an optimized geometry of a static upper end wall of the comb seal cavity by combining practical engineering constraint; The flow control area is specifically positioned near the inlet, in front of the comb teeth and between the comb teeth, and is used for flow retardation and leakage loss reduction, and the cross section shape of the flow control area meets the following conditions: the position near the inlet and the tooth space of the comb are in a straight line, the front part of the comb is provided with two arc lines, and the tooth space of the comb is in a straight line; The speed field matching area is specifically positioned behind the comb teeth of the sealing cavity and near the outlet and is used for controlling the flow leaving the sealing cavity to be matched with the speed field of the main flow so as to reduce the mixing loss, and the section shape of the speed field matching area meets the conditions that the comb teeth are two straight lines behind the comb teeth and the near outlet is a circular arc line; the speed field comprises radial speed, circumferential speed and axial speed.
2. 2. The method for realizing optimal fluidity of the sealing cavity of the comb teeth of the axial flow compressor according to claim 1, wherein the actual engineering constraint refers to the constraint considered by the safety work and the manufacturing and assembling requirements of the axial flow compressor in actual processing.
3. 3. The method for realizing optimized fluidity of the sealing cavity of the axial-flow compressor grate of claim 1, wherein the CFD numerical simulation calculation is that a numerical simulation method is adopted to solve a Reynolds average Navier-Stokes equation: Wherein: is a conservation-oriented parameter vector, which is used for the data processing, , And The non-viscous and viscous vector fluxes, , , As a heat source item, a heat source, , In the event of a stress being applied to the substrate, , For the kronecker symbol, Q is the source term, , Represents the external force to act on, Representing the work done by the external force, 。
4. 4. The method for optimizing flowability of a sealing cavity of a comb teeth of an axial flow compressor according to claim 1, wherein the performance is a total pressure loss coefficient of a stator blade And pressure coefficient Respectively is And Wherein p * is total pressure, p is static pressure, and subscripts in and out are inlet and outlet, respectively.

Description

Method for realizing optimal fluidity of sealing cavity of comb teeth of axial flow compressor Technical Field The invention relates to a technology in the field of impeller machinery, in particular to a realization method for optimizing fluidity of a sealing cavity of a comb teeth of an axial flow compressor. Background The axial flow compressor is one of important components of an aeroengine and a ground gas turbine, an abrasion-resistant coating is arranged at the inner ring of the blade root of a stator blade with an inner ring, a comb tooth sealing cavity is formed by the abrasion-resistant coating and a comb tooth machined on a rotor wheel disc, and a radial gap exists between the abrasion-resistant coating and the comb tooth sealing cavity so as to prevent the rotor stator from scraping during working. The prior comb tooth sealing cavity has single geometric shape, and the design method generally aims at designing and analyzing a plurality of specific geometric parameters, but the geometric freedom of the wall surface line of the sealing cavity is higher, the prior design method has limitations, and the prior design method lacks a more effective optimized geometric implementation method of the axial flow compressor comb tooth sealing cavity. Disclosure of Invention Aiming at the problems that the geometric shape of the existing comb seal cavity is single and the limitation of the design method is high, the invention provides a method for realizing the optimized fluidity of the comb seal cavity of an axial-flow compressor. The invention is realized by the following technical scheme: The invention relates to an optimized fluidity implementation method of a comb seal cavity of an axial flow compressor, which divides the interior of the comb seal cavity into a flow control area and a speed field matching area according to the flow characteristics in the comb seal cavity; and finally, carrying out flow analysis on the optimized geometry through CFD numerical simulation calculation, and evaluating the performance influence of the optimized geometry on the stator blade. The flow control area is particularly positioned at the near inlet, in front of the comb teeth and between the comb teeth and is used for flow retardation and reducing leakage loss, and the cross section shape of the flow control area meets the requirement that the flow control area is positioned at the near inlet and between the comb teeth and is in a straight line, the comb teeth are in front of two circular arc lines, and the comb teeth are in a straight line. The speed field matching area is specifically positioned behind the comb teeth of the sealing cavity and near the outlet and is used for controlling the flow leaving the sealing cavity to be matched with the speed field of the main flow so as to reduce the mixing loss, and the section shape of the speed field matching area meets the condition that the comb teeth are two straight lines behind the comb teeth and the near outlet is an arc line. The speed field comprises radial speed, circumferential speed and axial speed. The actual engineering constraint refers to the constraint considered in the actual processing due to the safe working and manufacturing and assembling requirements of the axial flow compressor. The CFD numerical simulation calculation is to solve a Reynolds average Navier-Stokes equation by adopting a numerical simulation method: Wherein: is a conservation-oriented parameter vector, which is used for the data processing, ,AndThe non-viscous and viscous vector fluxes,,,As a heat source item, a heat source,,In the event of a stress being applied to the substrate,,For the kronecker symbol,Q is the source term,,Represents the external force to act on,Representing the work that these external forces do,。 The performance refers to the total pressure loss coefficient of the stator bladeAnd pressure coefficient. Respectively isAndWherein p * is total pressure, p is static pressure, and subscripts in and out are inlet and outlet, respectively. These parameters are obtained by calculating the mass average of the total or static pressure over the whole inlet and outlet plane after the numerical simulation calculation. For better performance, the total pressure loss coefficient should be as small as possible and the pressure coefficient as high as possible. Technical effects According to the invention, through a partition mode, the targeted design is carried out according to the flow characteristics in different areas, so that the optimal performance of the stator blade is ensured. The invention improves the design efficiency of the comb teeth sealing cavity of the axial flow compressor, shortens the development time of an aeroengine or a ground gas turbine, and saves the development time and the labor cost. Drawings FIG. 1 is a schematic constraint diagram of a labyrinth seal cavity, wherein thick lines are design objects; FIG. 2 is a schematic diagram of the geometry and flow