RU2551015C1 - Method of operational development of experimental jet turbine engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to air-engine building, namely to air turbojets. The experimental double-circuit, two-shaft GTE is subjected to operational development. Operational development of TJE is performed step by step. At each phase from one to five TJEs are tested for compliance with the pre-set parameters. The program of tests with the subsequent finishing reworking includes tests of the engine for identification of influence of climatic effects on the change of operational performance of experimental JTE. Tests are performed with measurements of engine parameters at various operating conditions within programmed range of flight modes for particular engine range to reference measured parameters to standard atmospheric conditions with due allowance for variation of working body properties and geometric characteristics of engine air-gas channel.

EFFECT: improvement of turbojet performance, namely traction, experimentally tested resource and reliability of the engine by operation in the full range of flight cycles in various climatic conditions, and also in simplification of technology and reduction of labour costs and power consumption of turbojet test process at the phase of operational development of experimental TJE.

4 cl, 2 dwg

Description

The invention relates to the field of aircraft engine manufacturing, namely to aircraft turbojet engines.

Known dual-circuit, twin-shaft turbojet engine (turbojet engine), including turbocompressor complexes, one of which contains a compressor and a low pressure turbine mounted on one shaft, and the other contains a compressor and a high pressure turbine, an intermediate separation housing similarly combined on the other shaft, coaxial with the first between the mentioned compressors, external and internal circuits, the main and afterburner combustion chambers, a chamber for mixing gas-air flows of the working fluid and an adjustable nozzle (N.N.Siro tin et al. Fundamentals of designing the production and operation of aircraft gas turbine engines and power plants in the CALS technology system. Book 1. Moscow, Nauka publishing house. 2011, pp. 41-46, Fig. 1.24).

A well-known turbojet engine, which is double-circuit, contains a housing supported by compressors and turbines, a cooled combustion chamber, a fuel and pump group, a jet nozzle, as well as a control system with command and executive bodies (Shulgin V.A., Gaysinsky S.Ya Double-circuit turbojet engines of low-noise aircraft. M., ed. Mashinostroenie, 1984, pp. 17-120).

There is a known test method for refining aircraft turbojet engines, which consists in measuring parameters according to engine operating conditions and bringing them to standard atmospheric conditions, taking into account changes in the properties of the working fluid and geometric characteristics of the engine’s flow part when atmospheric conditions change (Yu.A. Litvinov, V.O. Borovik. Characteristics and operational properties of aircraft turbojet engines. Moscow: "Mechanical Engineering", 1979, 288 pp., Pp. 136-137).

A known method of testing aircraft engines of the turbojet type, including the development of predetermined modes, monitoring parameters and evaluating them resource and reliability of the engine. In order to reduce the test time during engine refinement of 10-20%, tests are carried out with the gas temperature in front of the turbine exceeding the maximum operating temperature by 45-65 ° C (SU 1151075 A1, publ. 10.08.2004).

Common shortcomings of these known technical solutions are the increased labor and energy intensity of tests and the insufficiently high reliability of engine traction assessment in a wide range of modes and regional temperature and climate conditions due to the inadequacy of the program for bringing specific test results performed in various temperature and climatic conditions to the results referred to to standard atmospheric conditions by known methods that do not take into account with sufficient accuracy Stu change parameters and modes of engine operation depending on the received programs adequate flight cycles, specific to a particular destination developed turbojet, which complicates the possibility of bringing the experimental test parameters to the parameters corresponding to the standard atmosphere.

The objective of the invention is to develop a method for fine-tuning an experimental turbojet engine, the combination of technical solutions of which provides improved thrust and increased reliability of operational characteristics for different temperature and climatic conditions of different regions and engine operating modes, as well as to simplify the technology and reduce labor costs and energy consumption of the turbojet test process stage of development of experimental turbofan engines with increasing representativeness of test results for the full range of conversion PARTICULAR situations in relation to the flight motor cycles in training and combat conditions in different regions and seasonal periods of operation.

The problem is solved in that in the method of refining an experimental turbojet engine of the type according to the invention, the prototype is subjected to refinement by a double-circuit, twin-shaft engine, while the engine is refined in stages, for which a program and algorithms for final testing of an experimental turbojet engine are developed; at each stage, a statistically representative amount, preferably from one to five copies, is tested for compliance with the specified parameters and the condition of each tested from the mentioned number of copies of the experimental engine is examined; for analysis and assessment of the condition, if necessary, disassemble, followed by possible refinement and / or replacement of parts of any of the modules and / or components of the experimental engine, inspect and, if necessary, replace any of the modules damaged in the tests or inadequate with the required parameters, including a low compressor pressure (KND) with an input guide vane (VNA) containing radial power racks, consisting of a fixed and controlled movable elements and evenly spaced in the plane Khodnev section with a corner frequency in the range of accommodation racks (3,0 ÷ 4,0) U / rad, and the rotor shaft, having, preferably, no more than four impellers with vanes system; a gas generator including assembly units — an intermediate casing, a high pressure compressor, a main combustion chamber and a high pressure turbine; sequentially located behind the gas generator, coaxially mounted low-pressure turbine; mixer; front-end device, afterburner combustion chamber and an all-mode jet nozzle connected to the afterburner; as well as an air-air heat exchanger module installed above the main combustion chamber in the external circuit, if necessary, inspecting any of at least sixty tubular block modules of the latter, in addition, they inspect and produce the necessary refinement of the drive box of the motor units and the electric, pneumatic unit of these modules hydraulic - fuel and oil - systems, including, if necessary, replacing sensors, command blocks, actuators and cables of diagnostic systems and automatic matic motor control; moreover, the test program with subsequent refinement includes testing the engine to determine the influence of climatic conditions (VKU) on changing the operational characteristics of the experimental turbojet engine; for this purpose, at least one test is carried out for representativeness, preferably three to five experimental engines; tests of the experimental engine are carried out in various modes, the parameters of which correspond to the parameters of the flight modes in the range programmed for a specific series of engines, make measurements and bring the obtained parameter values to standard atmospheric conditions, taking into account changes in the properties of the working fluid and geometric characteristics of the flow part of the turbojet engine when changing atmospheric conditions, while previously creating a mathematical model of a turbojet engine rectify it according to the results of bench tests of a representative amount of three to five identical turbojet engines, and then using the mathematical model determine the parameters of a turbojet engine under standard atmospheric conditions and various atmospheric air temperatures from a given operating temperature range of bench tests, taking into account the adopted engine control program for maximum and forced modes, and the actual values of the parameters at specific atmospheric temperatures about the air of each test mode, refer to the values of the parameters under standard atmospheric conditions and calculate the correction factors for the measured parameters depending on the atmospheric air temperature, and bringing the measured parameters to standard atmospheric conditions is carried out by multiplying the measured values by coefficients that take into account the deviation of atmospheric pressure from the standard, and by a correction factor reflecting the dependence of the measured values of the parameters on the temperature of the atmospheric air, registered in specific tests of turbojet engines.

Turbojet tests can be carried out with the measurement of its operation parameters in various modes, the parameters of which correspond to the values and limit values of the parameters of flight modes in the range programmed for a specific series of engines, and they bring the obtained parameters to standard atmospheric conditions taking into account changes in the properties of the working fluid and geometric characteristics of the engine’s flow part when atmospheric conditions change, while a preliminary mathematical model of the engine cite it according to the results of bench tests of a representative number of three to five engines, and then using the mathematical model determine the parameters of the engine under standard atmospheric conditions and various atmospheric air temperatures from a given operating temperature range of bench tests taking into account the adopted program of engine control at maximum and forced modes, moreover, the actual values of the parameters at specific atmospheric air temperatures of each test mode are referred to values of the parameters under standard atmospheric conditions and calculate the correction factors to the measured parameters depending on the temperature of the air, and bringing the measured parameters to standard atmospheric conditions is carried out by multiplying the measured values by coefficients that take into account the deviation of atmospheric pressure from the standard, and by a correction factor reflecting the dependence on air temperature recorded during specific tests, and taking into account the data obtained, by subsequent test cycle engine loading, in which changes in parameters.

They can be finished up with an experimental engine, the VNA of the low-pressure switch of which preferably contains twenty-three radial struts connecting the outer and inner rings of the VNA with the possibility of transferring loads from the external engine casing to the front support, and at least part of the struts is aligned with the channels of the oil system, placed in the stationary elements of the racks, with the ability to supply and drain oil, as well as venting the oil and pre-oil cavities of the front support of the low pressure rotor.

Finishing can be subjected to an experimental turbojet engine, the frontal area of the input opening F _{I. etc.} , VNA KND which geometrically determines the cross section of the inlet mouth of the air intake channel, bounded at a larger radius by the inner contour of the outer ring of the VNA, and on a smaller radius by the inner contour of the inner ring of the VNA, which is larger than the total area of aerodynamic shading F _c created by the frontal projection of the coke and radial racks, (2.54 ÷ 2.72) times and is (0.67 ÷ 0.77) of the total circle area F _pln. bounded by the radius of the inner contour of the outer ring of the BHA in the plane of the inlet opening.

The technical result provided by the given set of features consists in developing a method for tuning a turbojet engine with improved operational characteristics, namely, thrust and increased reliability of the indicated characteristics of the turbojet engine due to a more reliable and correct reduction of experimentally obtained engine parameters to parameters corresponding to standard atmospheric conditions, as well as in increasing the representativeness of the test results carried out at the stage of finalizing the experimental turbojet engines, for gender full range of flight cycles in various climatic conditions. This is achieved by the fact that, in accordance with the invention, a mathematical model of the engine is created before testing. A representative number of engines from a batch of experimentally produced turbojet engines are tested according to a developed program and a range of test modes. According to the test results, the mathematical model is corrected, by which, based on subsequent tests at specific temperatures, the engine parameters are determined under standard atmospheric conditions and various temperatures. Bringing the measured values of the parameters of specific tests to standard is carried out by means of correction factors.

The technical result achieved by the invention allows to simplify subsequent tests, increase the correctness and expand the representativeness of the assessment of the most important characteristics, primarily thrust with the correct distribution of representative estimates to a wide range of regional and seasonal conditions for subsequent flight operation of the engines.

The invention is illustrated by drawings, where:

figure 1 shows a turbojet engine, a longitudinal section;

figure 2 - input guide apparatus KND, top view.

In a method for refining a turbojet engine, a prototype engine is refined. The turbojet engine is double-circuit, twin-shaft. The engine refinement is carried out in stages, for which they develop a program and algorithms for the final testing of an experimental turbojet engine. At each stage, a statistically representative amount, preferably from one to five copies, is tested for compliance with the specified parameters, and the condition of each tested from the mentioned number of copies of the experimental engine is examined. For analysis and assessment of the condition, if necessary, disassemble is carried out with the subsequent possible refinement and / or replacement of parts of any of the modules and / or units of the experimental engine. Inspect and, if necessary, replace any module damaged in the tests or inadequate with the required parameters, if modified.

The turbojet engine contains at least eight modules - from a low-pressure compressor 1 to an all-regime adjustable jet nozzle 2. The low pressure pump includes an input guide apparatus 3, as well as a rotor with a shaft 4, containing preferably no more than four impellers 5 with a system of blades 6. VNA 3 contains power radial racks 7, consisting of a stationary hollow and controlled movable elements. Radial racks 7 are evenly spaced in the plane of the input section with the angular frequency of placement of racks in the range (3.0 ÷ 4.0) units / rad.

The gas generator includes assemblies, namely an intermediate housing 8, a high pressure compressor 9, a main combustion chamber 10 and a high pressure turbine 11. Behind the gas generator, a low pressure turbine 12, a mixer 13, a frontal device 14, an afterburner 15 of combustion and an all-mode jet nozzle 2 connected to the afterburner 15 of the combustion engine are sequentially mounted and coaxially mounted. An air-air heat exchanger module is installed in the external circuit of the turbojet engine above the main combustion chamber 10 16, if necessary, examining any of at least sixty tubular block modules of the latter.

In addition, they inspect and produce the necessary refinement of the box of drives of the motor units (not shown in the drawings) and combining the indicated electric, pneumatic, hydraulic modules - fuel and oil - systems, including, if necessary, replacing sensors, command blocks, actuators and cables of the diagnostic systems and automatic engine control.

The test program with subsequent refinement includes engine tests to determine the influence of climatic conditions (VKU) on changing the operational characteristics of an experimental turbojet engine. To do this, test at least one for representativeness, preferably three to five experimental engines. Tests of the experimental engine are carried out on various parameters. The parameters correspond to the parameters of flight modes in the range programmed for a specific series of engines. Measurements are made and the obtained parameter values are brought to standard atmospheric conditions, taking into account changes in the properties of the working fluid and geometric characteristics of the flow part of the turbojet engine with changing atmospheric conditions. In this case, a mathematical model of a turbojet engine is preliminarily created. The model is adjusted according to the results of bench tests of a representative amount of three to five identical turbojet engines. Then, using the mathematical model, the parameters of the turbojet engine are determined under standard atmospheric conditions and various atmospheric air temperatures from a given operating temperature range of bench tests, taking into account the adopted program for regulating the engine at maximum and forced modes. The actual values of the parameters at specific atmospheric air temperatures of each test mode are related to the values of the parameters under standard atmospheric conditions and correction factors are calculated for the measured parameters depending on the temperature of the atmospheric air. Bringing the measured parameters to standard atmospheric conditions is carried out by multiplying the measured values by coefficients that take into account the deviation of atmospheric pressure from the standard, and by a correction factor. The correction factor reflects the dependence of the measured parameter values on the temperature of the atmospheric air recorded in specific tests of the turbojet engine.

Variant tests of turbofan engines are carried out with the measurement of the parameters of its operation in various modes, the parameters of which correspond in magnitude and limit values of the parameters of flight modes in the range programmed for a specific series of engines. The obtained parameters are brought into standard atmospheric conditions, taking into account changes in the properties of the working fluid and geometric characteristics of the engine flow part when atmospheric conditions change. Also, in this case, a mathematical model of the engine is preliminarily created and adjusted according to the results of bench tests of a representative amount of three to five engines. Using a mathematical model, the engine parameters are determined under standard atmospheric conditions and various atmospheric air temperatures from a given operating temperature range of bench tests, taking into account the adopted engine control program at maximum and forced modes. The actual values of the parameters at specific atmospheric air temperatures of each test mode are related to the values of the parameters under standard atmospheric conditions and correction factors are calculated for the measured parameters depending on the temperature of the atmospheric air. Bringing the measured parameters to standard atmospheric conditions is carried out by multiplying the measured values by coefficients that take into account the deviation of atmospheric pressure from the standard, and by a correction factor that reflects the dependence on the temperature of the atmospheric air recorded during specific tests. Based on the data obtained, a subsequent test cycle is performed with engine loading, during which the change in parameters is evaluated.

The experimental engine is refined, VNA 3 KND 1 of which preferably contains twenty-three radial struts 7 connecting the outer and inner rings 17 and 18, respectively, of the VNA 3 with the possibility of transferring loads from the external engine casing 19 to the front support. At least a part of the struts 7 is combined with the channels of the oil system located in the stationary elements of the racks, with the possibility of supplying and discharging oil, as well as venting the oil and pre-oil cavities of the front support of the low pressure rotor.

The experimental turbojet engine is subjected to refinement, the frontal projection area of the entrance aperture is F _{in. etc.} , VNA 3 KND 1 which geometrically defines the cross section of the inlet mouth of the air intake channel 20, bounded at a larger radius by the inner contour of the outer ring 17 of the VNA 3, and at a smaller radius by the inner contour of the inner ring 18 of the VNA, exceeding the total aerodynamic shading area F _ct , created by the frontal projection of the Coca 21 and the radial racks 7, (2.54 ÷ 2.72) times and is (0.67 ÷ 0.77) of the total circle area F _pln. bounded by the radius of the inner contour of the outer ring 17 VNA in the plane of the inlet opening.

An example of the implementation of testing an experimental turbojet engine.

A representative group of three to five turbojet engines is tested. In this case, a previously developed mathematical model of the engine is used. Tests of the indicated group of turbojet engines are carried out at a temperature of t _BX = 0 ° C, Ba = 745 mm Hg.

According to the results of measurements and their statistical generalization, the following parameter values are obtained: engine thrust forces R = 985 kgf and rotation speed n = 98.8%.

For the subsequent evaluation of the test results, a mathematical model of the engine is used, according to which the parameters are calculated at various engine operating modes in the range of air temperatures at the engine inlet, including at t _BX = + 15 ° C. The calculation results are presented in Table 1

Table 1 t _VH , ° C -fifteen 0 +15 +30 Inlet temperature in turbojet engine R, kgf 1000 980 970 950 Traction force n,% 98 99 one hundred one hundred Rotation frequency

Compare the data obtained above and calculate the correction coefficients by the ratio of the parameter value at t _BX = + 15 ° C to the parameter values in a given temperature range at the engine inlet (Table 2)

table 2 t _VH , ° C -fifteen ± 0 +15 +30 K _r 0.97 0.99 one 1,021 Kn 1,02 1.01 one one

Then determine the parameters under standard atmospheric conditions (MSA)

, $$R_{MCA}=R\times K_R\times \frac{760}{Ba}=985\times 0.99\times \frac{760}{745}=995\mathrm{to}g\mathrm{from}$$

,

n _MCA = n × Kn = 98.8 × 1.01 = 97.79%

and enter the data into the accompanying documentation of the corresponding group of turbojet engines.

The parameters of the turbojet engine obtained above are used to calculate the corresponding parameters as applied to the temperature and climatic conditions of specific areas of engine operation in the range of operating outdoor temperatures t _BX = ± 50 ° C. Extreme values for the turbojet parameters for the indicated temperature range, obtained on the basis of test results using the mathematical model and data under standard atmospheric conditions (MSA), are presented in Table 3 and Table 4.

Table 3 t _VH , ° C -fifty -fifteen 0 +15 +20 +50 Inlet temperature in turbojet engine R, kgf 1200 1000 980 970 950 900 Traction force n,% 96 98 99 one hundred one hundred one hundred rotation frequency

Table 4 t _VH , ° C -fifty -fifteen 0 +15 +20 +50 K _r 0.81 0.97 0.99 one 1,021 1,078 Kn 1,042 1,02 1.01 one one one

From Table 3 and Table 4 it can be seen that the thrust in the extreme temperature range from (-50) ° C to (+50) ° C changes by one third when the speed changes by 4%.

Thus, the invention improves the reliability of the test results of turbojet engines, taking into account the adopted control programs.

The foregoing test sequence of the turbojet engine is used to assess thrust changes for various temperature and climate conditions and engine operating modes.

Claims (4)

1. A method of refining an experimental turbojet engine, characterized in that the experimental engine is refined, made by double-circuit, twin-shaft, while refining the engine is carried out in stages, for which a program and algorithms for refining tests of an experimental turbojet engine are developed; at each stage, a statistically representative amount of one to five instances is tested for compliance with the specified parameters and a condition is examined for each of the tested instances of the experimental engine; for analysis and assessment of the condition, disassembly is carried out, followed by possible refinement and / or replacement of parts of any of the modules and / or components of the experimental engine, examined and replaced with the modified one of any module damaged in the tests or not meeting the required parameters, including low pressure compressor (LPC) with an input guide vane (VNA) containing radial power racks consisting of a fixed and controlled movable elements and evenly spaced in the plane of the input section with an angular frequency azmescheniya racks in the range (3,0 ÷ 4,0) U / rad, and the rotor shaft, having, preferably, no more than four impellers with vanes system; a gas generator including assembly units — an intermediate casing, a high pressure compressor, a main combustion chamber and a high pressure turbine; sequentially located behind the gas generator, coaxially mounted low-pressure turbine; mixer; front-end device, afterburner combustion chamber and an all-mode jet nozzle connected to the afterburner; as well as an air-air heat exchanger module installed above the main combustion chamber in the external circuit, inspecting any of at least sixty tubular block modules of the latter, in addition, they inspect and refine the drive box of the motor units and the electrical, pneumatic, hydraulic units combining these modules fuel and oil - systems, including the replacement of sensors, command blocks, actuators and cables of diagnostic and automatic engine control systems; moreover, the test program with subsequent refinement includes testing the engine to determine the influence of climatic conditions (VKU) on changing the operational characteristics of the experimental turbojet engine; to do this, test at least one for representativeness of three to five experimental engines; tests of the experimental engine are carried out in various modes, the parameters of which correspond to the parameters of the flight modes in the range programmed for a specific series of engines, make measurements and bring the obtained parameter values to standard atmospheric conditions, taking into account changes in the properties of the working fluid and geometric characteristics of the flow part of the turbojet engine when changing atmospheric conditions, while previously creating a mathematical model of a turbojet engine rectify it according to the results of bench tests of a representative amount of three to five identical turbojet engines, and then using the mathematical model determine the parameters of a turbojet engine under standard atmospheric conditions and various atmospheric air temperatures from a given operating temperature range of bench tests, taking into account the adopted engine control program for maximum and forced modes, and the actual values of the parameters at specific atmospheric temperatures about the air of each test mode, refer to the values of the parameters under standard atmospheric conditions and calculate the correction factors for the measured parameters depending on the atmospheric air temperature, and bringing the measured parameters to standard atmospheric conditions is carried out by multiplying the measured values by coefficients that take into account the deviation of atmospheric pressure from the standard, and by a correction factor reflecting the dependence of the measured values of the parameters on the temperature of the atmospheric air, registered in specific tests of turbojet engines. 2. The method of fine-tuning the experimental turbojet engine according to claim 1, characterized in that the turbojet tests are carried out with the measurement of its operation parameters in various modes, the parameters of which correspond to the size and limit values of the parameters of flight modes in the range programmed for a specific series of engines, and carry out reduction of the obtained parameters to standard atmospheric conditions, taking into account changes in the properties of the working fluid and geometric characteristics of the engine’s flowing part when changing atmospheric conditions In this case, a mathematical model of the engine is preliminarily created, it is corrected according to the results of bench tests of a representative number of three to five engines, and then, according to the mathematical model, the engine parameters are determined under standard atmospheric conditions and various atmospheric air temperatures from a given operating temperature range of bench tests, taking into account adopted engine control program at maximum and forced modes, and the actual parameter values for specific x atmospheric air temperatures of each test mode are assigned to the parameter values under standard atmospheric conditions and correction factors are calculated for the measured parameters depending on the atmospheric air temperature, and the measured parameters are brought to standard atmospheric conditions by multiplying the measured values by coefficients that take into account the deviation of atmospheric pressure from the standard , and by the correction coefficient, which reflects the dependence on the temperature of atmospheric air, ingly in specific tests, and given the received data is performed subsequent test cycle engine loading, in which changes in parameters. 3. The refinement method of an experimental turbojet engine according to claim 1, characterized in that the experimental engine is subjected to refinement, VNA KND which contains twenty-three radial struts connecting the outer and inner rings of the VNA with the possibility of transferring loads from the external engine casing to the front support, and racks combined with the channels of the oil system located in the stationary elements of the racks, with the possibility of supplying and discharging oil, as well as venting the oil and pre-oil cavities of the front support of the low pressure rotor. 4. The refinement method of an experimental turbojet engine according to claim 3, characterized in that the experimental turbojet engine is subjected to refinement, the frontal projection area of the inlet opening is F _input. , VNA KND which geometrically determines the cross section of the inlet mouth of the air intake channel, bounded at a larger radius by the inner contour of the outer ring of the VHA, and on a smaller radius by the inner contour of the inner ring of the VNA, which is larger than the total area of aerodynamic shading F _c created by the frontal projection of the coke and radial struts, in (2.54 ÷ 2.72) times and is (0.67 ÷ 0.77) of the total area of the circle F _pln. bounded by the radius of the inner contour of the outer ring of the BHA in the plane of the inlet opening.

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