CN109632325B - Main combustion chamber flow distribution method - Google Patents
Main combustion chamber flow distribution method Download PDFInfo
- Publication number
- CN109632325B CN109632325B CN201811543807.4A CN201811543807A CN109632325B CN 109632325 B CN109632325 B CN 109632325B CN 201811543807 A CN201811543807 A CN 201811543807A CN 109632325 B CN109632325 B CN 109632325B
- Authority
- CN
- China
- Prior art keywords
- pressure
- flow
- characteristic curve
- flame tube
- hole
- 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
- G01M15/00—Testing of engines
- G01M15/14—Testing gas-turbine engines or jet-propulsion engines
Abstract
The application discloses a main combustion chamber flow distribution method, which comprises the following steps: keeping the inlet pressure and temperature and pressure constant, plugging a hole to be detected, measuring the relative difference between the pressure of an air flow at any position before entering the flame tube and the pressure of the flame tube at the outlet position, and calculating a reference pressure loss value to obtain a flow characteristic curve; and establishing a flow characteristic curve equation under the condition of plugging different holes to be tested, and calculating the flow distribution proportion of the flame tube according to the flow characteristic curve equation. According to the main combustion chamber flow distribution method, the air inlet normal-temperature normal-pressure environment is changed into constant temperature and pressure measurement by changing the test inlet state requirement, so that the influence of temperature and pressure fluctuation on the test result caused by the long-term work of the environment and equipment is avoided; secondly, no specific requirement is made on the pressure position behind the hole in front of the hole, and the flow characteristic curve is obtained by only selecting the relative difference between the pressure of the airflow entering any position or wall surface position of the flame tube and the outlet pressure of the flame tube as a reference loss value.
Description
Technical Field
The application belongs to the technical field of aero-engines, and particularly relates to a main combustion chamber flow distribution method.
Background
With the development of the main combustion chamber of the aero-engine towards higher oil-gas ratio and lower emission direction, the position of a combustion organization mode in the design of the main combustion chamber is gradually improved, and the flow distribution of the combustion chamber is the key for realizing the combustion organization and the design of the main combustion chamber.
At present, the most direct and effective method for obtaining the flow distribution is to adopt a hole plugging test method, and the traditional hole plugging method for obtaining the flow distribution of the combustion chamber can be summarized into the following two steps:
first, referring to the main combustion chamber test piece shown in fig. 1, a turbulator 1 is inside the test piece, and a liner air inlet hole 2 and a liner cooling hole 3 are circumferentially and uniformly distributed on the surface of the test piece. The method for obtaining the flow characteristic curve of each hole under normal temperature and normal pressure comprises the steps of blocking off non-measured holes, arranging a total pressure measuring point in front of each hole, arranging a static pressure measuring point behind each hole, changing the pressure difference delta P1 between the front of each hole and the rear of each hole and the flow G1 (the difference between the inlet air flow and the flow of two cavity channels) flowing through each combustion chamber by adjusting the inlet air flow of each combustion chamber, and drawing the flow characteristic curve of each hole according to the relation between different pressure differences and different flows.
The relationship between the flow rate characteristic curves Δ Pn and Gn for each orifice can be obtained by performing the test in accordance with the above procedure.
And then keeping the positions of the pressure measuring points of the rows of holes unchanged, opening all the holes, closing the flow valves of the two-strand cavity channels, simultaneously obtaining the values of delta P1-delta Pn, and finding out the flow G1-Gn by checking respective flow characteristic curves. Thus, the distribution ratio of the flow rate flowing through each orifice was Gi/Σ Gi (i is 1 to n), and the validity and applicability of the test was checked by checking Σ (Gi/Σ Gi) 1.
However, the above-mentioned plugging method for obtaining the main combustion chamber flow mainly has the following disadvantages:
1) the air inlet environment at normal temperature and normal pressure cannot be controlled, and in the test process, because the air source power works for a long time, the temperature and the pressure can change, the inlet temperature fluctuation of a large tester can be larger, and the inlet state fluctuation can directly influence the measurement result.
2) Pressure distribution position behind the hole before the hole of each hole can cause certain influence to the flow state, and the understanding of position behind the hole before the hole is different simultaneously to different designers, especially static pressure position behind the hole because go deep into the flame tube, is difficult to measure more, directly can cause the influence to follow-up flow result.
3) Various pressure distribution points are required to reserve corresponding measuring point positions when test pieces are designed, and a plurality of combustion chamber test pieces are not special flow distribution test pieces and cannot carry out accurate flow distribution measurement. Therefore, the traditional hole plugging method has narrow application level and range.
4) In the hole plugging test process, the non-measurement holes are plugged, the area of the plugged holes accounts for most of the area, and the area of the non-plugged holes is greatly different from the total opening area of the actual flame tube, so that the flowmeter always works in a small flow range, and the measurement error of the flowmeter can generate larger influence on the result.
In the hole plugging test in the prior art, the number of at least two flowmeters and pressure sensors is determined according to the opening of a combustion chamber, a hole which is not measured needs to be plugged in the hole plugging test process, the number of the plugged holes is large, the workload of the plugged holes is large, the efficiency is low, and the applicability to sigma (Gi/Sigma Gi) 1 is influenced by factors such as large area change of the plugged holes, difficulty in meeting requirements of arrangement of measuring point positions and the like, repeated tests are needed, the repeatability of test results is poor, and the working efficiency is reduced.
Disclosure of Invention
The purpose of the present application is to provide a main combustion chamber flow distribution method to solve any of the above problems.
The technical scheme of the application is as follows: a primary combustor flow distribution method, comprising: keeping the inlet pressure and temperature and pressure constant, plugging a hole to be detected, measuring the relative difference between the pressure of an air flow at any position before entering the flame tube and the pressure of the flame tube at the outlet position, and calculating a reference pressure loss value to obtain a flow characteristic curve; and establishing a flow characteristic curve equation under the condition of plugging different holes to be tested, and calculating the flow distribution proportion of the flame tube according to the flow characteristic curve equation.
Further, the method further comprises error judgment, and the error judgment process is as follows: and establishing a flow characteristic curve of the flame tube in the open-hole and full-open state, wherein the difference between the ratio of the sum of the flow of each hole under the specific reference pressure loss to the total flow under the full-open state and 1 is the error.
Further, the pressure at any position before entering the flame tube and the pressure at the outlet of the flame tube are total pressure or static pressure.
The main combustion chamber flow distribution method has the following advantages:
1) the requirement of the test inlet state is changed, the air inlet normal temperature and normal pressure environment is changed into constant temperature and pressure measurement, and particularly the temperature limit requirement is higher than the temperature of the air supply of the equipment, so that the influence of temperature and pressure fluctuation on the test result caused by the long-term work of the environment and the equipment is avoided;
2) the pressure position behind the hole is not specifically required, and the total pressure and static pressure parameters behind the hole are not specifically required to be measured, so that the positions of pressure measuring points are reduced. In the hole plugging test, only the relative difference between the pressure of any position or wall surface position before the airflow enters the flame tube and the pressure of the outlet of the flame tube is selected as a reference loss value to obtain a flow characteristic curve.
3) The flow distribution test does not need to reserve various pressure measuring point positions specially, only needs to use part of measuring points of the existing test piece to be arranged, reduces the quantity, and can expand the application range of the flow distribution test before the test of each stage of the combustion chamber and the detection of the processing of the test piece.
4) In the hole plugging test, only one type of holes are plugged or partial holes in one type of holes are plugged in batches at each time, the area of the plugged holes is small, the flow range change is small in the hole plugging test process, and the measurement precision is improved.
Drawings
In order to more clearly illustrate the technical solutions provided by the present application, the following briefly introduces the accompanying drawings. It is to be expressly understood that the drawings described below are only illustrative of some embodiments of the invention.
FIG. 1 is a schematic structural view of a test piece of a sector-shaped main combustion chamber.
FIG. 2 is a schematic view of a position of a measuring point according to an embodiment of the present application.
Fig. 3 is a graph of air flow rate versus pressure loss obtained in an example of the present application.
Detailed Description
In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application.
The flow distribution method for the main combustion chamber mainly comprises the following two steps:
the method comprises the following steps: keeping the inlet pressure and temperature and the pressure constant, plugging the hole to be detected, and calculating a reference pressure loss value by measuring the relative difference between the pressure of the airflow at any position before entering the flame tube 30 and the pressure of the outlet position of the flame tube to obtain a flow characteristic curve.
Referring to the schematic diagram of the measuring point positions of an embodiment shown in fig. 2, in the test process, the temperature and the pressure at the inlet M of the combustion chamber are kept constant, the inlet flow rate is adjusted to change, the relative pressure loss value is calculated by the pressure at the pressure measuring point P1 and the pressure at the outlet P2 of the combustion chamber, and characteristic curves of the flow rate and the pressure loss in the fully open state, different hole blocking states are drawn (which can be realized by adjusting the two branch channels 20). The pressure loss value is selected, and the difference between the pressure (which may be static pressure or total pressure) and the combustor exit pressure (which may be a multi-point average) at any position (which may be an average of one or two points as required) before the gas flow exits the pre-diffuser 10 into the liner is selected to calculate the pressure loss σ 1 (P1-P2)/P1.
Step two: and establishing a flow characteristic curve equation under the condition of plugging different holes to be tested, and calculating the flow distribution proportion of the flame tube according to the flow characteristic curve equation.
Specifically, each time only one type of hole is blocked, characteristic curves of flow rate characteristic curve loss σ 1 and flow rate G1 of the blocked hole are respectively obtained, a characteristic curve relation of Gn ═ f (σ n) is drawn, and a flow rate characteristic curve relation of different hole blocking states is established:
G1＝f1(σ1)
G2＝f2(σ2)
G3＝f3(σ3)
.......
Gn＝fn(σn)
in x1, x 2.., xn represents the flow size of a certain type of orifice under a certain σ x pressure loss (arbitrary position on the abscissa of the flow characteristic curve).
From the above curve relations, the following type of relations can be established:
x2+x3+...xn＝f1(σx)
x1+x3+...xn＝f2(σx)
x1+x2++x4...xn＝f3(σx)
.....
x1+x2+....xn-1＝fn(σx)
the system of equations is of the form
The equation on the right is known from the characteristic curve, and the equation set has n unknowns and n equations which are linear equations, so that x 1. The flow distribution proportion relation of each part is as follows:
the fully open flow rate at the pressure loss σ x is found as f (σ x) from the characteristic curve.
By passing
And (4) checking the applicability and the test error size of the method.
Taking the main combustion chamber shown in FIG. 1 as an example, if the proportional relationship of the flow distribution of the head, the wall surface of the flame tube, and the mixing holes is desired. By adopting the method, the head is blocked, and the characteristic curves of the flow G1 and the pressure loss in the state are measured; then, the wall cooling hole was blocked, the flow rate G2 and the pressure loss characteristic curve were measured, the mixing hole was blocked again, the flow rate G3 and the pressure loss characteristic curve were measured, and finally, the flow rate characteristic curve in the G4 full open state was obtained in the full open state, as shown in fig. 3.
The head, cooling and mixing orifice air flow rates are represented by x1, x2 and x3 respectively, and a pressure loss value sigma x is taken to be 3 percent, and the curve is obtained according to the relation:
x2+x3＝f1(3％)
x1+x3＝f2(3％)
x1+x2＝f3(3％)
then x1+ x2+ x3 ═ f1 (3%) + f2 (3%) + f3 (3%))/2;
percentage of head air: x1/((f1 (3%) + f2 (3%) + f3 (3%))/2);
percentage of cooling air: x2/((f1 (3%) + f2 (3%) + f3 (3%))/2);
percentage of blending air: x3/((f1 (3%) + f2 (3%) + f3 (3%))/2);
and (3) checking applicability and errors: ((f1 (3%) + f2 (3%) + f3 (3%))/2)/f (3%)) -1.
Compared with the prior art, the main combustion chamber flow distribution method of the application comprises the following steps:
1) the requirement of the test inlet state is changed, the air inlet normal temperature and normal pressure environment is changed into constant temperature and pressure measurement, and particularly the temperature limit requirement is higher than the temperature of the air supply of the equipment, so that the influence of temperature and pressure fluctuation on the test result caused by the long-term work of the environment and the equipment is avoided;
2) the pressure position behind the hole is not specifically required, and the total pressure and static pressure parameters behind the hole are not specifically required to be measured, so that the positions of pressure measuring points are reduced. In the hole plugging test, only the relative difference between the pressure of any position or wall surface position before the airflow enters the flame tube and the pressure of the outlet of the flame tube is selected as a reference loss value to obtain a flow characteristic curve.
3) The flow distribution test does not need to reserve various pressure measuring point positions specially, only needs to use part of measuring points of the existing test piece to be arranged, reduces the quantity, and can expand the application range of the flow distribution test before the test of each stage of the combustion chamber and the detection of the processing of the test piece.
4) In the hole plugging test, only one type of holes are plugged or partial holes in one type of holes are plugged in batches at each time, the area of the plugged holes is small, the flow range change is small in the hole plugging test process, and the measurement precision is improved.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (3)
1. The flow distribution method of the main combustion chamber is characterized by comprising
Keeping the inlet pressure and temperature and pressure constant, plugging one type of holes to be tested each time, measuring the relative difference between the pressure of the airflow at any position before entering the flame tube and the pressure at the outlet position of the flame tube, calculating a reference pressure loss value to obtain a flow characteristic curve, and drawing a characteristic curve relation of Gn ═ f (sigma n), wherein Gn is the flow and sigma n is the pressure loss;
establishing a flow characteristic curve equation under the state of plugging different holes to be tested:
G1＝f1(σ1)
G2＝f2(σ2)
G3＝f3(σ3)
.......
Gn＝fn(σn)
let x1, x 2.., xn represent the flow size of a certain type of orifice at a certain σ x pressure loss;
calculating the flow distribution proportion of the flame tube according to the flow characteristic curve equation:
x2+x3+...xn＝f1(σx)
x1+x3+...xn＝f2(σx)
x1+x2++x4...xn＝f3(σx)
.....
x1+x2+....xn-1＝fn(σx)
the system of equations is of the form
Thereby finding x1, x 2.., xn;
the flow distribution proportion relation of each part is as follows:
2. the main combustion chamber flow distribution method of claim 1, further comprising an error determination process, wherein the error determination process is: and establishing a flow characteristic curve of the flame tube in the open-hole and full-open state, wherein the difference between the ratio of the sum of the flow of each hole under the specific reference pressure loss to the total flow under the full-open state and 1 is the error.
3. The method of claim 1 wherein the pressure at any point prior to entering the liner and the pressure at the exit of the liner are total or static pressures.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811543807.4A CN109632325B (en) | 2018-12-17 | 2018-12-17 | Main combustion chamber flow distribution method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811543807.4A CN109632325B (en) | 2018-12-17 | 2018-12-17 | Main combustion chamber flow distribution method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109632325A CN109632325A (en) | 2019-04-16 |
| CN109632325B true CN109632325B (en) | 2021-05-25 |
Family
ID=66074707
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811543807.4A Active CN109632325B (en) | 2018-12-17 | 2018-12-17 | Main combustion chamber flow distribution method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109632325B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111859505B (en) * | 2020-07-15 | 2022-11-01 | 中国民航大学 | Flow distribution design method and device for miniature evaporation tube type combustion chamber |
| CN112197970B (en) * | 2020-09-21 | 2022-08-26 | 中国航发沈阳发动机研究所 | Design method of speed generator |
| CN115901268A (en) * | 2022-11-08 | 2023-04-04 | 中国航发沈阳发动机研究所 | Method for accurately acquiring total pressure loss coefficient of combustion chamber on engine |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1139476A (en) * | 1994-01-24 | 1997-01-01 | 西门子公司 | Combustion chamber for gas turbine |
| CN106907741A (en) * | 2017-02-16 | 2017-06-30 | 中国航发沈阳发动机研究所 | A kind of chamber structure |
| CN107036665A (en) * | 2016-11-23 | 2017-08-11 | 中国航空动力机械研究所 | A kind of experimental rig and method for measuring burner inner liner air admission hole discharge coefficient |
| CN107992655A (en) * | 2017-11-22 | 2018-05-04 | 北京动力机械研究所 | The quick Virtual Numerical Experiments method of deflector type combustion chamber aeroperformance |
| CN108562440A (en) * | 2017-12-26 | 2018-09-21 | 南京航空航天大学 | The combustor test device and its test method of air mass flow zonal control |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7650777B1 (en) * | 2008-07-18 | 2010-01-26 | General Electric Company | Stall and surge detection system and method |
-
2018
- 2018-12-17 CN CN201811543807.4A patent/CN109632325B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1139476A (en) * | 1994-01-24 | 1997-01-01 | 西门子公司 | Combustion chamber for gas turbine |
| CN107036665A (en) * | 2016-11-23 | 2017-08-11 | 中国航空动力机械研究所 | A kind of experimental rig and method for measuring burner inner liner air admission hole discharge coefficient |
| CN106907741A (en) * | 2017-02-16 | 2017-06-30 | 中国航发沈阳发动机研究所 | A kind of chamber structure |
| CN107992655A (en) * | 2017-11-22 | 2018-05-04 | 北京动力机械研究所 | The quick Virtual Numerical Experiments method of deflector type combustion chamber aeroperformance |
| CN108562440A (en) * | 2017-12-26 | 2018-09-21 | 南京航空航天大学 | The combustor test device and its test method of air mass flow zonal control |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109632325A (en) | 2019-04-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109632325B (en) | Main combustion chamber flow distribution method | |
| CN109506744B (en) | Air flow calibration method for venturi nozzle of aircraft engine complete machine test | |
| CN113221294B (en) | Method for obtaining expansion ratio of high-low pressure turbine under engine complete machine condition | |
| CN109977478B (en) | Evaluation method for coal mill inlet primary air flow field after optimization and transformation | |
| Arts et al. | Aerothermal performance measurements and analysis of a two-dimensional high turning rotor blade | |
| CN217384710U (en) | Air inlet system of air compressor tester | |
| US20140208755A1 (en) | Gas Turbine Air Mass Flow Measuring System and Methods for Measuring Air Mass Flow in a Gas Turbine Inlet Duct | |
| Suslov et al. | Test specimen design and measurement technique for investigation of heat transfer processes in cooling channels of rocket engines under real thermal conditions | |
| CN110656984B (en) | Device and method for measuring airflow at outlet of disk edge position of turbine disk | |
| US20160131146A1 (en) | Pressure sensor system for calculating compressor mass flow rate using sensors at plenum and compressor entrance plane | |
| Aalburg et al. | Annular cascade for radial compressor development | |
| CN109724659B (en) | Gas flow testing system and testing method for kitchen range | |
| RU2418281C1 (en) | Method for conducting stand-alone tests on mixed flow afterburners of bypass turbofan engines | |
| Drost et al. | Performance of a Turbine Airfoil With Multiple Film Cooling Stations: Part II—Aerodynamic Losses | |
| CN214408045U (en) | Direct-connected test bench air supply governing system | |
| Tillman et al. | Cooling airflow studies at the leading edge of a film-cooled airfoil | |
| Schaefer et al. | Some aspects on inlet blockage affecting the performance of a heavy duty gas turbine’s exhaust diffuser | |
| CN108386867B (en) | Turbulent burner Secondary Air On-line Measuring Method | |
| CN116562193B (en) | Combustion efficiency analysis method and system for rotary detonation engine | |
| CN113049253B (en) | Nozzle simulation device and fuel system experiment platform | |
| CN110083902A (en) | A kind of temperature distortion map mimetic design method based on discrete series | |
| US11391221B2 (en) | Mass flow metering method and system | |
| Macias | Investigation and Prediction of the Mixture Quality in Multi-Injector Burner Systems | |
| KR101242749B1 (en) | Method of pressure drop simulation for avionics | |
| CN116754023A (en) | Physical flow measurement structure and method suitable for non-uniform temperature distribution characteristics |
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 |