A method of controlling infrared radiation from a gas turbine engine exhaust

Abstract

The application discloses a kind of gas turbine engine exhaust infrared radiation control method.First, motor is installed on gas generator shaft, then gas turbine engine simulation model is established;Through the corresponding relationship between the gas turbine engine simulation model exhaust temperature, thrust and motor power under different flight Mach number is obtained.In the moment when engine exhaust temperature and infrared characteristics need to be adjusted, the input power or extraction power of motor is controlled, so as to adjust the air flow and oil-gas ratio, and then actively control the exhaust temperature and infrared radiation, realize the accurate simulation of infrared characteristics.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of infrared suppression technology of gas turbine engine, and particularly relates to a gas turbine engine exhaust infrared radiation control method. BACKGROUND

[0002] Most of the aircraft and helicopters use gas turbine engines as power sources, and the high-temperature exhaust of the engine makes the aircraft and helicopters widely face the threat of infrared guided weapons. Therefore, how to reduce the infrared radiation of the exhaust duct / tail nozzle of the gas turbine engine has become a research hotspot. Most of the current research reduces the infrared radiation from the perspective of the material and shape design of the exhaust duct / tail nozzle.

[0003] For marine gas turbine engines, due to the large exhaust flow rate, the high-temperature exhaust will not only affect the infrared stealth performance, but also have a negative impact on the equipment, the working environment of the crew and the overall design of the ship. Therefore, marine gas turbine engines also face the urgent need to reduce the infrared radiation and temperature of the exhaust.

[0004] As an important tool for testing weapon performance, the target needs to simulate the infrared characteristics of the threat target. Due to the diversity of the threat target, the infrared radiation of the target is not the lower the better, and it needs an engine exhaust infrared control technology that can flexibly adjust the infrared radiation of the engine exhaust to accurately simulate the infrared characteristics of different targets. SUMMARY

[0005] The present application provides a gas turbine engine exhaust infrared radiation control method, which can flexibly adjust the infrared radiation of the engine exhaust to accurately simulate the infrared characteristics of different targets.

[0006] The present application provides a gas turbine engine exhaust infrared radiation control method, which includes:

[0007] establishing a gas turbine engine simulation model;

[0008] obtaining the corresponding relationship between the exhaust temperature, the thrust and the motor power at different flight Mach numbers through the gas turbine engine simulation model;

[0009] controlling the exhaust temperature based on the corresponding relationship and the interpolation of the gas generator shaft motor power.

[0010] Specifically, the establishing of the gas turbine engine simulation model includes:

[0011] The component characteristics of the compressor, turbine and tail nozzle are obtained through component characteristic experiments or three-dimensional fluid calculation, on the basis of which a flow continuity equation, a power balance equation and a pressure ratio-expansion ratio equation set are constructed, the above-mentioned nonlinear equation set is solved through a Newton-Raphson method, the common working point of each component is determined, and on the basis of this, a gas turbine engine simulation model is established in combination with a gas thermodynamic property calculation method.

[0012] Specifically, after the corresponding relationship among the exhaust temperature, thrust and motor power under different flight Mach numbers is obtained through the gas turbine engine simulation model, the method further comprises:

[0013] The upper and lower limits of the motor power under different flight Mach numbers and engine thrust conditions are determined.

[0014] Specifically, the determination of the upper and lower limits of the motor power under different flight Mach numbers and engine thrust conditions comprises:

[0015] The motor power under different flight Mach numbers and different engine thrust conditions is calculated respectively, the changes of the compressor outlet pressure, the combustor outlet total temperature, the gas generator rotating speed and the compressor surge margin with the motor power are observed, and the upper and lower limits of the motor power are determined.

[0016] Specifically, the obtaining of the gas generator shaft motor power based on the corresponding relationship for controlling the exhaust temperature comprises:

[0017] The different gas generator shaft motor powers are obtained based on the corresponding relationship, and the different gas generator shaft motor powers are output as control signals to the motor for controlling the exhaust temperature.

[0018] Specifically, the method further comprises: performing closed-loop control on the engine thrust through fuel flow.

[0019] Specifically, the closed-loop control on the engine thrust through fuel flow comprises:

[0020] The current engine thrust is calculated according to the atmospheric temperature, pressure, flight Mach number, equivalent rotating speed and motor power, and the thrust is taken as a feedback signal to realize closed-loop control on the thrust through adjustment of fuel flow.

[0021] The one or more technical solutions provided in the application have at least the following technical effects or advantages:

[0022] First, the motor is installed on the shaft of the gas generator, and then the simulation model of the gas turbine engine is established; the corresponding relationship between the exhaust temperature, the thrust and the motor power under different flight Mach numbers is obtained through the simulation model of the gas turbine engine. At the moment when the exhaust temperature and the infrared characteristics of the engine need to be adjusted, the input power or the extracted power of the motor is controlled to adjust the intake flow rate and the oil-gas ratio, and then the exhaust temperature and the infrared radiation are actively controlled to realize the accurate simulation of the infrared characteristics.

[0023] In addition, the present application also has the following advantages:

[0024] (1) By adjusting the input power or the extracted power of the motor of the gas generator, the intake flow rate and the oil-gas ratio are controlled to flexibly adjust the exhaust temperature and the infrared radiation of the gas turbine engine while maintaining the engine thrust unchanged.

[0025] (2) Through the simulation, the effectiveness of the exhaust infrared radiation control method of the gas turbine engine based on the hybrid electric propulsion can be verified. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structural diagram of the single-shaft turbojet engine in the embodiment of the present application;

[0027] Figure 2 It is a corresponding relationship curve between the engine intake flow rate and the motor output power;

[0028] Figure 3 It is a corresponding relationship curve between the engine oil-gas ratio and the motor output power;

[0029] Figure 4 It is a flow chart of the exhaust infrared radiation control method of the gas turbine engine provided by the embodiment of the present application;

[0030] Figure 5 It is a corresponding relationship curve between the compressor common working point and the motor output power;

[0031] Figure 6 It is a corresponding relationship curve between the combustion chamber outlet temperature and the motor output power;

[0032] Figure 7 It is a control principle diagram of the exhaust infrared radiation control method of the gas turbine engine provided by the embodiment of the present application;

[0033] Figure 8 It is a corresponding relationship curve between the engine exhaust temperature and the motor output power after the exhaust infrared radiation control method of the gas turbine engine provided by the embodiment of the present application is adopted. DETAILED DESCRIPTION

[0034] The embodiment of the present application can flexibly adjust the infrared radiation of the engine exhaust to realize accurate simulation of different target infrared characteristics by providing a gas turbine engine exhaust infrared radiation control method.

[0035] The technical solution in the embodiment of the present application is as follows to achieve the above technical effects:

[0036] The embodiment of the present application adds an electric machine on the gas generator shaft by using hybrid electric propulsion technology, as shown in Figure 1 The electric machine is mechanically connected with the gas generator shaft, and the rotational speed of the electric machine is in a fixed speed ratio transmission with the gas generator shaft, so that the electric machine can extract power from the gas generator shaft or provide power to the gas generator shaft by doing work, and drive the compressor together with the turbine. By inputting / extracting power to the compressor rotor, the intake flow is increased / decreased, and the oil-gas ratio is reduced / increased, so as to achieve the purpose of reducing / increasing the exhaust temperature and infrared radiation, as shown in Figure 2 and Figure 3 In the design process of the exhaust temperature control law, the output power of the electric machine under different engine operating conditions and flight conditions is determined by using a simulation model / engine test bench. By using the gas turbine engine exhaust infrared radiation control method provided by the embodiment of the present application, the infrared radiation generated by the high-temperature exhaust of the gas turbine engine can be effectively controlled while ensuring that the engine output power / thrust remains unchanged.

[0037] Specifically, in the determination process of the exhaust temperature control law, the corresponding relationship between the engine exhaust temperature (T8), the engine thrust (FN), and the output shaft power (Pow) and the electric machine output power (Pe) for a turboshaft engine or a gas turbine is determined under different Ma, and Ma has a direct impact on the corresponding relationship between T8, FN (or Pow) and Pe. And the above T8, FN, POW and Pe are all converted parameters, which need to be converted to the actual parameters under the current engine inlet conditions when used.

[0038] The high-precision simulation model of the gas turbine engine in the embodiment of the present application is a component-level simulation model, which is established by solving power balance equations and flow continuity equations based on component aerodynamic characteristics, can simulate and calculate the temperature and pressure of each section of the engine, the thrust (for turboshaft engine / gas turbine, the output shaft power), the rotational speed, the compressor surge margin, and the common working point of the components, and can simulate the changes of the engine operating conditions with the gas generator shaft electric machine power under different atmospheric environments and flight conditions.

[0039] The engine thrust (or output power) is predicted by means of an on-board model, and the required motor power is determined by using a target corrected exhaust temperature (T8cor), a corrected thrust (or corrected output power) and a flight Mach number (Ma) and an interpolation exhaust temperature control law. When the required motor power exceeds the established upper and lower motor power limits, the motor outputs power according to the corresponding upper / lower limit to prevent the engine from exceeding the limit.

[0040] In the determination of the upper and lower limits of the motor power, in order to generalize the determination results to different engine inlet conditions, the engine thrust (or output power), the motor power, the compressor outlet pressure and the combustion chamber outlet temperature are all calculated according to the corrected parameters. In the process of calculating the motor power by the control system, the upper and lower limits of the motor power are converted to the actual parameters under the current engine inlet conditions. The determination of the upper and lower limits of the motor power can ensure that the engine always works within the safe ranges of the combustion chamber outlet temperature, the exhaust temperature, the compressor surge margin, the compressor outlet pressure and the gas generator speed.

[0041] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings in the specification and specific embodiments.

[0042] Referring to Figure 4 The gas turbine engine exhaust infrared radiation control method provided by the embodiment of the present application comprises:

[0043] Step S110: establishing a gas turbine engine simulation model;

[0044] The gas turbine engine simulation model is established, which comprises:

[0045] The component characteristics of the compressor, the turbine and the tail nozzle are obtained through component characteristic experiments or three-dimensional fluid calculation, and on this basis, a flow continuity equation, a power balance equation and a pressure ratio-expansion ratio equation set are constructed, the above nonlinear equation set is solved by the Newton-Raphson method to determine the common working points of the components, and on this basis, a gas turbine engine simulation model is established by combining a gas thermodynamic property calculation method. The model can accurately simulate the engine cross-section temperature and pressure, thrust, speed, compressor surge margin and component common working point.

[0046] Step S120: obtaining the corresponding relationship between the exhaust temperature, the thrust (or output power) and the motor power under different flight Mach numbers (Ma) by the gas turbine engine simulation model;

[0047] Specifically, on the basis of the established gas turbine engine simulation model, the exhaust corrected temperature (T8 cor), the corresponding relationship between the equivalent thrust (FN cor ) and the equivalent output power (Pe cor ) of the motor, and a motor power interpolation table, i.e., an exhaust temperature control law, is made. In the controller design, the equivalent output power (Pe cor ) of the motor can be determined by interpolating the exhaust temperature control law with Ma, T8 cor and FN cor .

[0048] Further, the process of obtaining the exhaust temperature control law is as follows: the corresponding relationship between the exhaust temperature, the thrust (for the output shaft power of a turboshaft engine or a gas turbine, the output power) and the motor power under different flight Mach numbers (Ma) is determined through engine tests or a high-precision simulation model. The above-mentioned exhaust temperature (T8), thrust (FN), output shaft power (Pow) and motor output power (Pe) are all equivalent parameters, which need to be converted to actual parameters under the current engine inlet conditions when used. The following formula is the expression of each equivalent parameter:

[0049]

[0050]

[0051]

[0052]

[0053] wherein T0 (K) and P0 (kPa) are the engine inlet total temperature and total pressure. Pow cor is the output shaft equivalent power.

[0054] In order to prevent the engine pressure, temperature and speed from being too high or the surge margin from being too low, after obtaining the corresponding relationship between the exhaust temperature, the thrust and the motor power under different flight Mach numbers through the simulation model of the gas turbine engine, the following steps are further included:

[0055] The upper and lower limits of the motor power under different flight Mach numbers and engine thrust (or output power) conditions are determined. When the motor power is positive, the motor supplements mechanical power to the gas generator shaft; when the motor power is negative, the motor extracts mechanical power from the gas generator shaft.

[0056] Specifically, the upper and lower limits of the motor power under different flight Mach numbers and engine thrust conditions are determined, including:

[0057] The motor power under different flight Mach numbers and different engine thrust conditions is calculated respectively, the changes of the compressor outlet pressure, the combustor outlet total temperature, the gas generator speed and the compressor surge margin with the motor power are observed, the upper and lower limits of the motor power are determined, and a motor power limit table is made. For example,Figure 5 As shown, with the increase of motor power, the engine speed and pressure ratio rise, and the engine has the risk of over-speed and over-pressure, so the upper limit of the engine speed and the pressure after the compressor determines the upper limit of the motor power, and the minimum power in the motor power corresponding to the engine speed reaching the upper limit and the pressure after the compressor reaching the upper limit is taken as the upper limit of the motor power.

[0058] Figure 5 And Figure 6 It is also shown that with the decrease of motor power, the total temperature at the outlet of the combustion chamber increases and the compressor surge margin decreases, and the engine has the risk of over-temperature and surge, so the maximum combustion chamber outlet temperature of the engine and the minimum allowable surge margin of the compressor determine the lower limit of the motor power, and the maximum power in the motor power corresponding to the combustion chamber outlet temperature reaching the upper limit and the compressor surge margin reaching the minimum allowable value is taken as the lower limit of the motor power.

[0059] As Figure 7 shown, in the controller design, the motor equivalent power upper and lower limits can be determined by interpolating the motor power limit table through Ma and FN cor .

[0060] In order to prevent the engine from exceeding the limit, if the Pe cor obtained by interpolating the exhaust temperature control law is less than the lower limit of the motor equivalent power, the lower limit of the motor equivalent power is output; if the Pe cor obtained by interpolating the exhaust temperature control law is greater than the upper limit of the motor equivalent power, the upper limit of the motor equivalent power is output; if the Pe cor obtained by interpolating the exhaust temperature control law is between the upper and lower limits of the motor equivalent power, the Pe cor is output as it is.

[0061] Step S130: obtaining the gas generator shaft motor power based on the correspondence interpolation to control the exhaust temperature.

[0062] Specifically, the gas generator shaft motor power is obtained based on the correspondence interpolation to control the exhaust temperature, which includes:

[0063] The corresponding gas generator shaft motor power is calculated based on the correspondence interpolation, and different gas generator shaft motor powers are output as control signals to the motor to control the exhaust temperature.

[0064] In order to prevent the engine thrust from deviating from the target value during the adjustment of the exhaust temperature, thereby improving the simulation accuracy, it further includes: closed-loop control of the engine thrust (or output power) by the fuel flow.

[0065] Specifically, the closed-loop control of the engine thrust by the fuel flow includes:

[0066] According to the atmospheric temperature, pressure, flight Mach number, equivalent rotating speed, motor power, current engine thrust is calculated, and the thrust is taken as a feedback signal to realize closed loop control of the thrust by adjusting the fuel flow.

[0067] As shown in Figure 7 Atmospheric temperature, atmospheric pressure, Ma, engine equivalent rotating speed and motor power can be obtained by sensors, and the engine on-board model calculates engine thrust and equivalent thrust through these parameters, which are used for fuel flow control and motor control respectively. The fuel control system forms a closed loop control on the engine thrust. When the exhaust temperature needs to be controlled, Ma, FNcor and T8cor interpolate the exhaust temperature control law, and the motor power is limited through the motor power limit table, so as to prevent the occurrence of high pressure, temperature and rotating speed and compressor surge caused by motor control.

[0068] In order to prove the effectiveness of the gas turbine engine exhaust infrared radiation control method provided by the embodiment of the present application, the established gas turbine engine exhaust temperature control strategy is substituted into the gas turbine engine simulation model, and it is verified whether the turbojet engine can always realize the control of the exhaust temperature under the premise of maintaining the target value of the thrust under different T0, P0, Ma and thrust conditions. The temperature regulation range should be greater than 100K, and the control strategy should always keep the compressor outlet pressure, the combustion chamber outlet temperature, the rotating speed and the compressor surge margin within the safe range. If the control strategy can make the engine meet the above requirements, it is proved that the control method provided by the embodiment of the present application is effective. As shown in Figure 8 When the motor power is 1000kW, the engine exhaust temperature is reduced by more than 130K, and it can be seen that the adjustment of the exhaust temperature by the motor is effective.

[0069] The embodiment of the present application discloses a kind of based on hybrid electric propulsion's gas turbine engine exhaust infrared radiation control method. Hybrid electric propulsion technology is used to install motor on the shaft of gas generator, adjusts fuel flow and oil-gas ratio by motor input power or extracting power to the compressor, and then controls the exhaust temperature and infrared radiation of engine. In addition, the engine thrust (or output power) is predicted by means of on-board model, so that closed loop control of thrust (or output power) is realized by fuel flow. The embodiment of the present application can not only be used for single-shaft turbojet engine, but also can be used for other structures of gas turbine engine, such as turbofan engine, turboshaft engine, turboprop engine, gas turbine, etc.

[0070] Those skilled in the art will appreciate that embodiments of the present application can be devised for a variety of applications. It is intended that the present application be limited only by the scope of the appended claims, and it is intended that various modifications and alterations made by those skilled in the art be considered as within the scope of the present application. The embodiments of the present application will be described with reference to the attached drawings, wherein:

[0071] The present application is described in reference to the drawings using a flowchart illustration and / or a block diagram of the method, apparatus (system) and computer program product according to embodiments of the application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processing device or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart Figure 1 one or more functions specified in the flowchart block or blocks. Figure 1 one or more functions specified in the flowchart block or blocks.

[0072] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more functions specified in the flowchart block or blocks. Figure 1 one or more functions specified in the flowchart block or blocks.

[0073] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more functions specified in the flowchart block or blocks. Figure 1 one or more functions specified in the flowchart block or blocks.

[0074] While the preferred embodiments of the application have been described, additional variations and modifications can be made to the embodiments by those skilled in the art once they learn of the basic inventive concepts. Therefore, the appended claims are intended to cover all such modifications and variations as fall within the scope of the present application.

[0075] Obviously, many modifications and variations of the present application are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A method of controlling infrared radiation from a gas turbine engine exhaust, characterized by, The motor is mechanically connected with the gas generator shaft, and the motor speed and the gas generator shaft speed are in a fixed ratio transmission, so that the motor can extract power from the gas generator shaft and provide power to the gas generator shaft through the motor, and the motor drives the compressor together with the turbine, and the method comprises: establishing a gas turbine engine simulation model; obtaining the corresponding relationship between the exhaust temperature, the engine thrust and the motor power under different flight Mach numbers through the gas turbine engine simulation model; after obtaining the corresponding relationship between the exhaust temperature, the engine thrust and the motor power under different flight Mach numbers through the gas turbine engine simulation model, further comprising: determining the upper and lower limits of the motor power under different flight Mach numbers and engine thrust conditions, comprising: respectively calculating the changes of the adjusted motor power, the compressor outlet pressure, the combustor outlet total temperature, the gas generator speed and the compressor surge margin with the motor power under different flight Mach numbers and different engine thrust conditions, and determining the upper and lower limits of the motor power; based on the corresponding relationship, interpolating to obtain the required motor power, and controlling the exhaust temperature, when the required motor power exceeds the upper and lower limit range of the motor power, the motor outputs power according to the corresponding upper limit or lower limit.

2. The gas turbine engine exhaust infrared radiation control method of claim 1, wherein, The establishment of the gas turbine engine simulation model comprises: obtaining the component characteristics of the compressor, the turbine and the tail nozzle through component characteristic experiments or three-dimensional fluid calculation, and on this basis, constructing a flow continuity equation, a power balance equation and a pressure ratio expansion ratio equation set, solving the nonlinear equation set composed of the above flow continuity equation, power balance equation and pressure ratio expansion ratio equation set by Newton-Raphson method to determine the common working point of each component, and on this basis, combining with the gas thermodynamic property calculation method, establishing the gas turbine engine simulation model.

3. The gas turbine engine exhaust infrared radiation control method of claim 1, wherein, The interpolation based on the corresponding relationship to obtain the required motor power to control the exhaust temperature comprises: interpolating different required motor powers based on the corresponding relationship, and outputting the different required motor powers as control signals to the motor to control the exhaust temperature.

4. The gas turbine engine exhaust infrared radiation control method of claim 1, wherein, Further comprising: closed-loop control of the engine thrust by the fuel flow.

5. The gas turbine engine exhaust infrared radiation control method of claim 4, wherein, The closed-loop control of the engine thrust by the fuel flow comprises: calculating the current engine thrust according to the atmospheric temperature, the atmospheric pressure, the flight Mach number, the engine equivalent speed and the motor power, and taking the engine thrust as a feedback signal to realize closed-loop control of the engine thrust by adjusting the fuel flow.

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