CN112417595B - Method for evaluating installation thrust of aircraft engine - Google Patents
Method for evaluating installation thrust of aircraft engine Download PDFInfo
- Publication number
- CN112417595B CN112417595B CN202011303404.XA CN202011303404A CN112417595B CN 112417595 B CN112417595 B CN 112417595B CN 202011303404 A CN202011303404 A CN 202011303404A CN 112417595 B CN112417595 B CN 112417595B
- Authority
- CN
- China
- Prior art keywords
- airplane
- coefficient
- aircraft
- resistance
- airport
- 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
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/15—Vehicle, aircraft or watercraft design
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/17—Mechanical parametric or variational design
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Geometry (AREA)
- Theoretical Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Pure & Applied Mathematics (AREA)
- Mathematical Optimization (AREA)
- Mathematical Analysis (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Computational Mathematics (AREA)
- Automation & Control Theory (AREA)
- Aviation & Aerospace Engineering (AREA)
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
- Testing Of Engines (AREA)
Abstract
The application belongs to the field of aircraft engine design and relates to an aircraft engine installation thrust evaluation method, which comprises the following steps: acquiring lift coefficient and drag coefficient of the airplane at different attack angles; calculating the lift force and aerodynamic resistance of the airplane in the take-off or high-speed sliding state according to the lift force coefficient and the resistance coefficient; calculating the friction resistance of the airport according to the friction coefficient of the airport when the airplane takes off or slides at a high speed; and acquiring the acceleration of the aircraft in the process of taking off from sliding to completely leaving the ground, constructing a balance equation according to a Newton second law, and calculating the installation thrust of the aero-engine. Compared with a fuel gas generator method, the method does not need parameters of the outlet section of the engine spray pipe, and can be applied to the installation thrust evaluation of military turbofan engines. Compared with an airplane push resistance balancing method, the method does not need accurate airplane aerodynamic characteristics, and when the aerodynamic resistance is set to be zero, the evaluation error is not more than 3% within the takeoff and sliding range of not more than 150 km/h.
Description
Technical Field
The application belongs to the field of aircraft engine design, and particularly relates to an aircraft engine installation thrust evaluation method.
Background
After the military small bypass ratio engine is installed, the thrust level of the engine cannot be directly measured in the actual flight test process. The existing evaluation methods mainly comprise a fuel gas generator method and an airplane push resistance balancing method. The gas generator method utilizes the performance of an engine bench as a reference, and evaluates the total thrust level of the engine by combining the measurement parameters of the main aerodynamic section of the engine in flight through the dimensionless quantity conversion relation of the total thrust.
The gas generator method has large dependence on pneumatic parameters of main sections of the engine, particularly has high requirement on measurement accuracy of nozzle sections of the engine in flight, and for military turbofan engines, because the outlet of a jet pipe of the engine in flight is positioned in a high-temperature area, the actual area, temperature, pressure and other parameters of the outlet of the jet pipe cannot be directly measured, the method has large evaluation errors when being used for military aircraft.
Disclosure of Invention
In order to accurately evaluate the engine installation thrust, reduce the dependence on the aerodynamic characteristics of an airplane, reduce the dependence on main section parameters of the engine and obtain real-time flight performance, the engine installation thrust evaluation method based on takeoff/high-slip data is provided.
The application provides an aircraft engine installation thrust evaluation method, which comprises the following steps:
s1, obtaining lift coefficients and drag coefficients of an airplane at different attack angles;
s2, calculating lift force and aerodynamic resistance of the airplane in a take-off or high-speed sliding state according to the lift force coefficient and the resistance coefficient;
s3, calculating the friction resistance of the airport according to the friction coefficient of the airport when the airplane takes off or slides at a high speed;
and S4, acquiring the acceleration of the aircraft in the process of sliding to completely liftoff takeoff, constructing a balance equation according to a Newton second law, and calculating the installation thrust of the aero-engine.
Preferably, in step S1, a lift coefficient and a drag coefficient of the aircraft are acquired through a wind tunnel test.
Preferably, in step S4, the balance equation includes:
wherein m is the aircraft mass, F is the aircraft engine installation thrust, alpha is the flight angle of attack, phi is the engine thrust angle, X is the aerodynamic drag during the aircraft taxiing process, and D is the airport frictional drag.
Preferably, the airport frictional resistance D is calculated using the following formula:
D＝f[G-Y-F sin(α+φ)]
wherein f is the friction coefficient of an airport, G is the weight of the airplane, and Y is the lift force of the airplane in the sliding process.
Preferably, in step S4, when the acceleration calculation is performed during the process of taking off the aircraft from taxiing to completely liftoff, the time interval is selected to be not less than 1 second.
The application has the advantages that: the required airborne measurement parameters are conventional parameters, the dependence degree on the aerodynamic characteristics of the airplane is low, the evaluation precision is high, and the engineering application threshold is low.
Drawings
FIG. 1 is a flow chart of a preferred embodiment of the aircraft engine installation thrust evaluation method of the present application.
FIG. 2 is a schematic diagram of the relationship between thrust, drag and ground speed during takeoff.
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 accompanying drawings in the embodiments of the present application. 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 some, but not all embodiments of the present application. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application, and should not be construed as limiting the present application. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the embodiments in the present application are within the scope of protection of the present application. Embodiments of the present application will be described in detail below with reference to the drawings.
The application provides an aircraft engine installation thrust evaluation method, as shown in fig. 1, which mainly comprises the following steps:
s1, obtaining lift coefficients and drag coefficients of an airplane at different attack angles;
s2, calculating lift force and aerodynamic resistance of the airplane in a take-off state or a high-speed sliding state according to the lift force coefficient and the drag coefficient;
s3, calculating the friction resistance of the airport according to the friction coefficient of the airport when the airplane takes off or slides at a high speed;
and S4, acquiring the acceleration of the aircraft in the process from sliding to completely liftoff takeoff, constructing a balance equation according to a Newton second law, and calculating the installation thrust of the aircraft engine.
The engine installation thrust evaluation method based on take-off/high-slip data provided by the application is described in detail below in terms of acceleration calculation, aircraft drag lift calculation and an engine installation thrust balance equation.
(1) Calculating acceleration according to the ground speed:
point selection suggestion: in the calculation process, the selected time interval is not less than 1 second (burr is avoided), the engine state is stable (accelerator, rotating speed, boosting, oil supply and the like), the pilot releases the brake, and the airplane is in the take-off/high-slip process.
(2) Aircraft drag during takeoff/high glide:
the resistance X and the lift Y are obtained by the formula (1), and the airport friction resistance D is as follows: obtained from equation (2).
D＝f[G-Y-F sin(α+φ)] (2)
Wherein: c x -a drag coefficient; c y -a lift coefficient; c z -a lateral force coefficient; a-the effective wing area of the aircraft; x-resistance; y-lift force; z-lateral force; v-airspeed (ground speed may be substituted); ρ -air density.
Determining the lift coefficient and the lift coefficient of the airplane:
acquiring the lift and drag coefficient characteristics of the airplane according to the actual wind tunnel test result of the airplane; if the actual lift-drag characteristics of the aircraft are not grasped, the general coefficients shown in tables 1 and 2 can be used in third generation fighter planes with effective wing areas of 52-72 m 2. The general characteristics shown in tables 1 and 2 are the results of lift coefficient and drag coefficient obtained by a wind tunnel test for a typical fighter.
TABLE 1 typical aircraft Lift coefficient C y
TABLE 2 typical aircraft drag coefficient C x
(3) Engine installation thrust:
and (4) obtaining the engine installation thrust by the formulas (3) and (4). When two installation, single installation thrust: f single shot = F/2, the method cannot distinguish thrust performance of each of the double shots.
In the formula: g-aircraft real-time weight;
m-airplane real-time mass = G/9.8;
f, engine installation thrust;
alpha-angle of flight;
phi-engine thrust angle;
f-airport friction coefficient;
x-aerodynamic drag;
v-ground speed.
According to the method, the balance equation shows that the factors influencing the reasonability of the installation thrust mainly comprise the following steps:
1) Airport friction resistance coefficient: all general airports used 0.035, and this coefficient was estimated to vary by 14%, i.e. f =0.04, with a single thrust impact of about 60kgf and a smaller impact (0.6%);
2) Residual thrust: the occupation ratio is the largest, which is a key factor for evaluating the thrust, and the ground speed is adopted for calculation, so that the measurement method is relatively accurate;
3) Aircraft aerodynamic drag:
as shown in FIG. 2, for the engine side, when the takeoff/high-slip mounting thrust is evaluated, the biggest problem is that the accurate aerodynamic characteristics of the airplane are not available, and when the ground speed is 100km/h, 150km/h and 250km/h (without corresponding), the aerodynamic resistance accounts for 1.5%, 3% and 9% of the mounting thrust, and the proportion of the factor is smaller when the speed is lower. On the premise of no airplane aerodynamic characteristics, aerodynamic resistance can be ignored or a similar airplane type is adopted for replacement, and the evaluation error of the installation thrust is not more than 3% in the evaluation result within the speed range of 0-150 km/h. Therefore, the similar machine models can be adopted for the aerodynamic resistance evaluation, and the evaluation error can be further reduced.
Under the condition of no airplane aerodynamic characteristics, the general characteristics can be adopted for evaluation, and the installation thrust evaluation is relatively accurate within the range of the ground speed not greater than 150 km/h.
Compared with a fuel gas generator method, the method does not need parameters of the outlet section of the engine spray pipe, and can be applied to the installation thrust evaluation of military turbofan engines. Compared with an airplane push resistance balancing method, the method does not need accurate airplane aerodynamic characteristics, and when the aerodynamic resistance is set to be zero, the evaluation error is not more than 3% within the takeoff and sliding range of not more than 150 km/h.
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 (2)
1. An aircraft engine installation thrust evaluation method is characterized by comprising the following steps:
s1, obtaining lift coefficients and drag coefficients of an airplane at different attack angles;
s2, calculating lift force and aerodynamic resistance of the airplane in a take-off or high-speed sliding state according to the lift force coefficient and the resistance coefficient;
s3, calculating the friction resistance of the airport according to the friction coefficient of the airport when the airplane takes off or slides at a high speed;
s4, acquiring the acceleration of the aircraft in the process from sliding to completely liftoff takeoff, constructing a balance equation according to a Newton second law, and calculating the installation thrust of the aircraft engine;
in step S4, the balance equation includes:
wherein m is the aircraft mass, F is the installation thrust of an aircraft engine, alpha is the flight attack angle, phi is the engine thrust angle, X is the aerodynamic drag during the aircraft sliding process, and D is the airport friction drag;
the airport friction resistance D is calculated by adopting the following formula:
D＝f[G-Y-Fsin(α+φ)]
wherein f is the friction coefficient of an airport, G is the weight of the airplane, and Y is the lift force of the airplane in the sliding process;
in the step S4, when the acceleration calculation is carried out in the process that the airplane takes off from sliding to completely liftoff, the selected time interval is not less than 1 second.
2. The aircraft engine installation thrust evaluation method according to claim 1, wherein in step S1, the lift coefficient and the drag coefficient of the aircraft are obtained through a wind tunnel test.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011303404.XA CN112417595B (en) | 2020-11-19 | 2020-11-19 | Method for evaluating installation thrust of aircraft engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011303404.XA CN112417595B (en) | 2020-11-19 | 2020-11-19 | Method for evaluating installation thrust of aircraft engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112417595A CN112417595A (en) | 2021-02-26 |
| CN112417595B true CN112417595B (en) | 2022-11-22 |
Family
ID=74773545
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011303404.XA Active CN112417595B (en) | 2020-11-19 | 2020-11-19 | Method for evaluating installation thrust of aircraft engine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112417595B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113945386B (en) * | 2021-09-19 | 2023-08-22 | 中国航空工业集团公司西安飞机设计研究所 | Thrust determination method for ground pulley dynamic test engine of hair extension system |
| CN114544180A (en) * | 2021-12-29 | 2022-05-27 | 中国航空工业集团公司沈阳飞机设计研究所 | Engine large throttle evaluation method and device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110816874A (en) * | 2019-10-11 | 2020-02-21 | 成都飞机工业（集团）有限责任公司 | Method for identifying balance pole curve of double-engine airplane through ground taxi test |
| CN111382522A (en) * | 2020-03-17 | 2020-07-07 | 中国人民解放军空军工程大学 | Aircraft engine installation thrust evaluation method based on takeoff and running data |
-
2020
- 2020-11-19 CN CN202011303404.XA patent/CN112417595B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110816874A (en) * | 2019-10-11 | 2020-02-21 | 成都飞机工业（集团）有限责任公司 | Method for identifying balance pole curve of double-engine airplane through ground taxi test |
| CN111382522A (en) * | 2020-03-17 | 2020-07-07 | 中国人民解放军空军工程大学 | Aircraft engine installation thrust evaluation method based on takeoff and running data |
Non-Patent Citations (1)
| Title |
|---|
| 某型飞机高原机场起飞滑跑距离的分析和计算;侯照等;《山东农业大学学报(自然科学版)》;20180716(第04期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112417595A (en) | 2021-02-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111382522B (en) | Aeroengine installation thrust evaluation method based on take-off and running data | |
| CN112417595B (en) | Method for evaluating installation thrust of aircraft engine | |
| Covert | Progress In Astronautics and Aeronautics: Thrust and Drag: Its Prediction and Verification | |
| Guynn et al. | Initial assessment of open rotor propulsion applied to an advanced single-aisle aircraft | |
| CN105279290A (en) | Four-engine propeller airplane endurance performance calculating method | |
| Henderson et al. | Jet noise prediction comparisons with scale model tests and Learjet flyover data | |
| Rindlisbacher et al. | Guidance on the determination of helicopter emissions | |
| Zalovcik et al. | Flight investigation of boundary-layer transition and profile drag of an experimental low-drag wing installed on a fighter-type airplane | |
| Borst | Summary of Propeller Design Procedures and Data. Volume I. Aerodynamic Design and Installation | |
| HANCOCK et al. | Inlet Development for the L-500 | |
| Brines | Studies for determining the optimum propulsion system characteristics for use in a long range transport aircraft | |
| McCarthy | The JSF STOVL performance process from small-scale database to flight test demonstration | |
| Bousquet | Survey of engine integration testing in ONERA wind tunnels | |
| Gracey et al. | Flight investigation of the variation of static-pressure error of a static-pressure tube with distance ahead of a wing and a fuselage | |
| Paterson et al. | An Analysis of Flight Test Data on the C-141A Aircraft | |
| Lovesey | Modern methods of testing aero-engines and power plants | |
| Rolls | A flight comparison of a submerged inlet and a scoop inlet at transonic speeds | |
| Bencze | Experimental evaluation of nacelle-airframe interference forces and pressures at Mach numbers of 0.9 to 1.4 | |
| Kohl et al. | Investigation of a Full-Scale, Cascade-Type Thrust Reverser | |
| Bergman | Exhaust nozzle drag: Engine vs airplane force model | |
| Gur et al. | Installation Effect on Hover Propeller Performance | |
| Black et al. | Aerodynamic design and performance testing of an advanced 30 deg swept, eight bladed propeller at Mach numbers from 0.2 to 0.85 | |
| Hughes et al. | Effects of inlet distortion on a static pressure probe mounted on the engine hub in an F-15 airplane | |
| WARD et al. | Instrumentation of a light twin aircraft for flow energizer flight tests | |
| Borst | Propeller Performance and Design as Influenced by the installation |
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 |