Patent Application
20240263923
The invention relates to a system for generating temperature-controlled thermal traces for target aircraft.
Target aircraft are generally unmanned aerial vehicles that can mimic enemy aircraft and missiles in terms of speed, maneuver, thermal, or radar traces in military exercises or missile development projects. Thanks to these capabilities, they can be used in missile development projects such as air-air/ground-air missile systems or air defense systems, in military training and exercises such as anti-aircraft shooting and radar tracking, and many different tasks such as the measurement of opportunities and capabilities such as target detection and tracking of combat aircraft.
In order to generate the thermal trace needed in the target aircraft, heating systems are usually installed on the nose of the aircraft in a way that will not disrupt the aerodynamic integrity of the aircraft. The thermal trace or radiation generated by this heating system is directly proportional to the surface temperature of the system. This high radiation ensures that the infrared seeker head or thermal measurement devices are locked at a greater distance from the target. For these thermal trace enhancing systems, two types of methods, usually fueled and electric, are used. Although these two types of methods have advantages over each other, the main determining criterion is their applicability to the existing aircraft.
The Taiwanese patent document TWM281166, which is included in the known state of the art, describes a switching system heater that brings a thermal target to a predetermined temperature for use in the tests of heat-guided missiles. By virtue of a temperature sensor in the system configuration, the combustion temperature of the combustion chamber is continuously measured, and when the temperature value is lower than a predetermined value, the temperature sensor can turn on the switch and transmit electricity to the ignition structure for ignition to take place, thus ensuring that the temperature is brought to a predetermined value by ignition and combustion.
The Great Britain patent document EP0876579, which is included in the known state of the art, refers to a thermal unit having a temperature sufficient to enable detection and monitoring by an infrared search defense weapon system. The thermal unit, which is mounted on the air target, comprises a thermally conductive surface to generate a thermal trace and a combustion chamber using propane or MAP GAS as fuel, providing continuous heating of the surface.
With a thermal trace enhancer system developed by this invention, it is ensured that the temperature is adjusted to the desired value and the system can be started at any desired time. Due to low fuel consumption, a system for a target aircraft is developed that does not restrict the operation time of the aircraft, does not require external cooling, can reach high temperatures due to the lack of a rotating part under high temperature and has low maintenance costs.
The thermal trace enhancer system realized to achieve the object of the invention, defined in the first claim and in the claims dependent on this claim, is coupled to a body on an air vehicle in the type of a target aircraft/target unmanned aerial vehicle to provide propulsion and enables the air vehicle's movement using at least one engine. With a thermal unit positioned on the body in a different location from the engine, preferably in the nose region where the body first encounters the wind, thermal trace enhancement and performance testing and simulation of infrared sensing devices are performed. In order to let the thermal unit increase the thermal trace, at least one combustion chamber is provided on the thermal unit, in which a combustion reaction is performed to generate hot gases and to which the air required for the combustion reaction is taken through at least one air intake and the fuel is supplied accordingly. Hot gases released by the combustion reaction in the combustion chamber, in turn, hit the thermal surface having almost a spherical form, increasing the temperature of the conductive surface and then leaving the thermal unit through at least one exhaust outlet.
The thermal trace enhancer system according to the invention comprises a compressor in the thermal unit to compress the air taken from the atmosphere through the air intake, reduce its volume and increases its pressure, then supplies the high-pressure air to the combustion chamber to be used for the combustion reaction, thus increasing the efficiency of the combustion process. The compressor is triggered by at least one actuator situated in the cold section of the thermal unit during the period in which it makes a rotational motion. By adjusting the number of revolutions of the actuator with a signal transmitted to the actuator by a control unit, the flow rate of the air taken by the compressor is adjusted and the temperature of the thermal surface is kept at a user-preferred temperature.
In an embodiment of the present invention, the thermal trace enhancer system does not require an additional fuel tank due to the fact that both the engine used to enable the movement of the air vehicle and the thermal unit used to increase the thermal trace are supplied with kerosene and its derivatives or diesel and its derivatives, thereby saving weight and volume.
In an embodiment of the invention, the thermal trace enhancer system comprises at least one fuel pump enabling the temperature of the thermal surface to be adjusted to a value as desired by the user by controlling the amount of fuel required for the combustion process in the combustion chamber according to a signal transmitted from the control unit.
In an embodiment of the present invention, the thermal trace enhancer system can control the flow rate of air received in the thermal unit by a signal transmitted to the actuator and the amount of fuel delivered to the combustion chamber by a signal transmitted to the fuel pump by the control unit, respectively. Thanks to the airflow rate and fuel flow rate, which can be controlled independently of each other, the temperature value for the thermal surface can be kept at a value desired by the user at lower ambient temperatures and higher air speeds.
In an embodiment of the invention, the thermal trace enhancer system enables the value of the temperature that is desired by the user to take place on the thermal surface to be adjusted by means of at least one thermocouple used to obtain instantly measured temperature data from the thermal surface or the exhaust outlet. The instantaneous temperature data measured by at least one thermocouple is transmitted to the control unit and evaluated, and when the thermal surface temperature is below a user-desired value, the amount of air and/or fuel taken is increased by a command transmitted by the control unit to the actuator and/or the fuel pump. Since the thermal unit may be damaged or create a fire risk when the thermal surface temperature is above a user-desired value, it is enabled to reduce the amount of air and/or fuel taken by a command transmitted by the control unit to the actuator and/or the fuel pump, respectively.
In an embodiment of the invention for the thermal trace enhancer system, the control unit uses the data measured by at least one sensor on the air vehicle to detect the air vehicle's speed, altitude, ambient temperature, static and dynamic air pressure and transmits a signal to the actuator and/or to the fuel pump, respectively, to control the flow rate of air and the amount of fuel feeding the thermal unit to bring the thermal surface to a user-desired temperature.
In an embodiment of the invention, the thermal trace enhancer system comprises at least one fuel supply line used by the air vehicle to deliver kerosene and its derivatives or diesel and its derivatives to the combustion chamber, and an evaporator to gasify the liquid fuel delivered by the fuel supply line and to inject it into the combustion chamber to be used in the combustion reaction.
In an embodiment of the invention for the thermal trace enhancer system, an igniter disposed in the combustion chamber and having a temperature enough to evaporate the fuel triggers the combustion reaction by providing the sparking to let the fuel injected into the combustion chamber by the evaporator and the pressurized air from the compressor enter into a chemical reaction. Since the combustion will then continue only with fuel and air, the use of the igniter is critical for initiating the combustion reaction.
In an embodiment of the present invention for the thermal trace enhancer system, the thermal unit is initiated during flight by virtue of the control unit's capabilities to activate/deactivate and control the levels of the igniter providing the first ignition, the fuel pump adjusting the amount of fuel and the actuator adjusting the flow rate of air, thereby eliminating the need to operate it on the ground and saving fuel and energy.
In an embodiment of the invention, the thermal trace enhancer system provides the heating of the thermal surface by passing hot gases through the inner surface through at least one opening on an inner surface that is the first contact surface of hot gases released as a result of the combustion reaction in the combustion chamber. Preferably, the position of the opening on the dome-shaped inner surface is preferably centered on the dome top. The distance between the inner surface and the thermal surface narrows towards the exhaust outlet, and thanks to the hot gas passing through the narrower volume, the thermal surface is heated more efficiently.
In an embodiment of the invention for the thermal trace enhancer system, in order to bring the thermal surface temperature to a temperature by which infrared sensing devices such as an air defense system, a missile to be tested etc. can be detected, the control unit controls the actuator and/or the fuel pump to adjust the thermal surface.
In an embodiment of the invention, the thermal trace enhancer system prevents the risk of fire in the aircraft or damage to the thermal unit under high temperature by adjusting the amount of air taken by the compressor and the control unit to actively cool the temperature of the thermal surface by closing the thermal unit.
In an embodiment of the invention, the thermal trace enhancer system utilizes electric motors to actuate an axial or centrifugal compressor that rotates during the period of operation of the thermal unit. Electric motors can be direct current motors with or without brushes. A brushless direct current motor is preferred as an actuator due to its compact, high speed and low maintenance costs.
In an embodiment of the invention, the thermal trace enhancer system instantly measures the number of revolutions of the actuator and transmits it to the control unit so that the number of revolutions is controlled with a closed-loop control system. Thus, the number of revolutions that will provide the required air flow rate can be controlled by comparing the measured number of revolutions with the number of revolutions according to the signal transmitted by the control unit.
The thermal trace enhancer system realized to achieve the object of the present invention is shown in the attached figures, wherein these figures;
The parts illustrated in figures are individually assigned a reference numeral and the corresponding terms of these numbers are listed below.
The thermal trace enhancer system (1) comprises a body (2) situated on the air vehicle, at least one engine (E) enabling to move the body (2) to which it is connected, a thermal unit (3) situated on the body (2) so as to be spaced apart from the engine (E), enabling to generate hot gases to increase the thermal trace, at least one air intake (4) provided in the thermal unit (3), enabling air to enter into the thermal unit (3) from the atmosphere, at least one combustion chamber (5) enabling hot gases to be generated as a result of the chemical reaction of fuel and the air taken through the air intake (4), a conductive thermal surface (6) enabling to increase the thermal trace by heat transfer with hot gases leaving the combustion chamber (5) hitting on itself, and at least one exhaust outlet (7) enabling the gases heating up the thermal surface (6) to exit the thermal unit (3) (
The thermal trace enhancer system (1) according to the invention comprises a compressor (8) situated in the thermal unit (3), enabling to compress the air taken through the air intake (4) and to transmit it to the combustion chamber (5), thereby increasing the combustion efficiency, an actuator (9) enabling the compressor (8) to make a rotational movement, and a control unit (10) adjusting the number of revolutions of the actuator (9), thereby enabling to achieve the temperature on the thermal surface (6) as desired by the user.
A thermal unit (3) which can rise to high temperatures in order to increase the thermal trace, is placed on an aerodynamic surface called a body (2) situated on an air vehicle, which can be any of a target aircraft/target UAV. The thermal unit (3) is preferably positioned in the nose region, which is the surface where the air vehicle first encounters the wind. The thermal unit (3), which is positioned separately from at least one engine (E) that enables the air vehicle to move, is heated by the formation of hot gases in at least one combustion chamber (5) therein as a result of the chemical reaction of fuel and the air taken through at least one air intake (4) on the thermal unit (3). The hot gases generated in the combustion chamber (5) heat the conductive thermal surface (6) in a convectional manner and increase its thermal visibility by devices such as missiles and air defense systems. At least one exhaust outlet (7) is provided for hot gases hitting the thermal surface (6) to exit the thermal unit (3). (
Thanks to a compressor (8) in the thermal unit (3), the air taken from the atmosphere through the air intake (4) is compressed as a result of its radial or axial movement and its pressure is increased so that the performance and efficiency of the combustion reaction in the combustion chamber (5) are enhanced. The number of revolutions of the compressor (8) is adjusted according to a command transmitted from a control unit (10) by an actuator (9) providing the radial movement required for the operation of the compressor (8) so that the flow rate of the air taken in is increased or decreased and the temperature of the thermal surface (6) is kept at the value as desired by the user. (
In an embodiment of the invention for the thermal trace enhancer system (1), the thermal unit (3) burns kerosene and its derivatives or diesel and its derivatives used by the engine (E) to generate hot gases. The thermal unit (3) enabling to increase the thermal trace and the engine (E) enabling the air vehicle to move are situated in independent positions, but both use kerosene and its derivatives or diesel and its derivatives as fuel to perform their functions. Volume saving is achieved by using the same type of fuel from the same tank (
In an embodiment of the invention, the thermal trace enhancer system (1) comprises at least one fuel pump (11) enabling to achieve the temperature desired by the user for the thermal surface (6) by adjusting the flow rate of fuel to be used for the combustion process in the combustion chamber (5). Increasing the amount of fuel used in the combustion reaction can increase the temperature of the thermal surface (6). Decreasing the amount of fuel, in turn, can reduce the temperature the thermal surface (6). The ability to adjust the temperature of the thermal surface (6) to a value desired by the user can be achieved by controlling the flow rate of fuel by means of the fuel pump (11).
In an embodiment of the invention for the thermal trace enhancer system (1), the control unit (10) allows to keep and control the temperature of the thermal surface (6) at the desired value by the user by independently adjusting the air flow rate with a command it transmits to the actuator (9) and the amount of fuel with a command it transmits to the fuel pump (11). Thanks to the signal transmitted by the control unit (10) to the actuator (9), the air flow rate to the combustion chamber (5), and thanks to the signal transmitted to the fuel pump (11), the amount of fuel received in the combustion chamber (5) can be independently controlled so that the temperature of the thermal surface (6) can be adjusted by the user to the desired value.
In an embodiment of the invention for the thermal trace enhancer system (1), the control unit (10) controls the actuator (9) and/or the fuel pump (11) according to temperature data received by means of at least one thermocouple (12) situated at the thermal surface (6) and/or the exhaust outlet (7) to keep the temperature at a user-preferred value. Thanks to the thermocouples (12) situated on the thermal surface (6) and/or the exhaust outlet (7), temperature data are instantaneously measured, the measured data are evaluated in the control unit (10), and signals are transmitted by the control unit (10) to the actuator (9) and/or the fuel pump (11) so that the temperature of the thermal surface (6) can be adjusted to a user-preferred value (
In an embodiment of the invention the thermal trace enhancer system (1) comprises at least one sensor (13) on the air vehicle, enabling to measure the speed, altitude, air temperature, air static and/or dynamic pressure data of the air vehicle so that the control unit (10) controls the actuator (9) and/or the fuel pump (11) according to the data transmitted to it by the sensor (13) and keeps the temperature of the thermal surface (6) at a user-preferred value. By virtue of the sensors (13) situated on the air vehicle, the air vehicle's speed, the ambient temperature, the static and/or dynamic air pressure are measured instantly and the data are transmitted to the control unit (10). As a result of sending the commands, which are generated by the control unit (10) according to the data received, to the actuator (9) and/or the fuel pump (11), a user-preferred temperature on the thermal surface (6) can be obtained.
In an embodiment of the invention, the thermal trace enhancer system (1) comprises at least one fuel supply line (14) enabling to deliver the air vehicle's fuel into the combustion chamber (5), and at least one evaporator (15) converting the liquid fuel from the fuel supply line (14) into a gas form so that it can be injected into the combustion chamber (5). In order to ensure that the combustion process is initiated in the thermal unit (3) using liquid fuel for the combustion process, the liquid fuel transmitted by the fuel supply line (14) is injected into the combustion chamber (5) by means of evaporators (15) and is transmitted in a gaseous form. In this way, liquid fuel is chemically reacted with air to form hot gases (
In an embodiment of the invention, the thermal trace enhancer system (1) comprises at least one igniter (16) having a temperature that evaporates the fuel and ignites it in the combustion chamber (5). The igniter (16) has a temperature to evaporate the fuel and ignites the injected fuel transmitted by the evaporator (15) to the combustion chamber (5), enabling the first combustion to begin. It is deactivated once the first combustion starts and the temperature of the combustion chamber (5) reaches a certain value (
In an embodiment of the invention for the thermal trace enhancer system (1), the control unit (10) enables the thermal unit (3) to be operated during flight by sending commands to the igniter (16), the fuel pump (11) and the actuator (9). Thanks to the commands transmitted by the control unit (10) to the igniter (16) for igniting the injected fuel, to the actuator (9) for adjusting its number of revolutions to adjust the amount of compressed air in the combustion chamber (5), and to the fuel pump (11) for adjusting the amount of fuel delivered to the combustion chamber (5), the combustion process does not need to be initiated on the ground. By igniting the fuel during flight and continuing the combustion process, it is ensured that the thermal surface (6) can be adjusted to a user-preferred value.
In an embodiment of the invention, the thermal trace enhancer system (1) comprises an inner surface (17), which is the first contact surface of hot gases exiting the combustion chamber (5), at least one opening (18) situated on the inner surface (17), enabling hot gases to heat the thermal surface (6) by passing through the inner surface (17), and an inner surface (17) in a form in which the distance between the thermal surface (6) and itself becomes narrower towards the exhaust outlet (7). Hot gases formed as a result of the combustion reaction in the combustion chamber (5) pass through the openings (18) on the inner surface (17), thereby hitting and heating the conductive thermal surface (6). In order for hot air to better transmit its heat energy to the thermal surface (6), the distance between the thermal surface (6) and the inner surface (17) towards the exhaust outlet (7) is narrowed. The reason for this narrowing is that the thermal surface (6) is almost completely hemispherical in compliance with the aerodynamic flow, the form of the inner surface (17) is almost completely semi-dome-shaped with a cut top, and that the inner surface (17) is placed into the thermal surface (6).
In an embodiment of the invention for the thermal trace enhancer system (1), the temperature of the thermal surface (6) can be adjusted by the control unit (10) according to a temperature as required for detection by devices taking infrared images. The temperature of the thermal surface (6) can be adjusted by the user to a desired value by controlling the actuator (9) and/or the fuel pump (11) by means of the control unit (10) as a result of the user previously entering into the control unit (10) the temperature required for devices such as missiles, air defense systems etc. to be tested.
In an embodiment of the invention for the thermal trace enhancer system (1), the compressor (8) enables to cool the thermal surface (6) in order to reduce the thermal trace in the air vehicle by making use of the air taken in through the air intake (4). Cold air taken through the air intake (4) is used to ensure that fire risks as a result of overheating of the thermal surface (6), or other risks as a result of the hot parts of the thermal unit (3) reaching temperatures that it is not structurally able to withstand are eliminated.
In an embodiment of the invention for the thermal trace enhancer system (1), the actuator (9) is in the type of an electric motor enabling to actuate an axial or centrifugal compressor (8). The electric motor can be a direct current motor with or without brushes. In particular, brushless direct current motors are preferred to drive the axial or centrifugal compressor (8) making a rotational motion, since they are easy to maintain, take up little space, easily controlled and they can reach high speeds.
In an embodiment of the invention, the thermal trace enhancer system (1) comprises at least one revolution speed sensor (19) that detects the number of revolutions of the actuator (9) and transmits the number of revolutions signal to the control unit (10). In order for the thermal surface (6) to be kept at a value desired by the user, the required air flow rate must be taken into the thermal unit (3). In order to adjust the air flow rate, the number of revolutions of the actuator (9) is detected by the revolution speed sensor (19) and transmitted to the control unit (10) so that the value measured by the revolution speed sensor (19) and the signal transmitted by the control unit (10) are compared to run the actuator (9) at a proper number of revolutions with a newly transmitted signal from the control unit (10).
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021/009278 | Jun 2021 | TR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/TR2022/050532 | 6/6/2022 | WO |
