Adaptive controllable jet ramjet combined engine and its working method and application

Abstract

The present invention provides an adaptive controllable jet ramjet combination engine and its working method and application, the combination engine includes an air inlet, a combustion chamber, a tail nozzle, a small flow rocket and a large flow rocket; the air inlet, the combustion chamber and the tail nozzle are connected end to end in sequence; the small flow rocket is matched and installed in the combination section of the combustion chamber; the large flow rocket is matched and installed on the outside of the tail nozzle, and its air outlet is connected to the inner cavity of the tail nozzle; when the large flow rocket is started, its rocket plume can promote the formation of the aerodynamic throat in the tail nozzle; the tail nozzle is matched and installed with a rotating adjustment plate at the part connected to the air outlet of the large flow rocket. The present invention installs rockets in the flow channel in the combustion chamber and on the outside of the tail nozzle, and meets the requirements of high thrust and effective specific impulse required by the aircraft during the acceleration process in the ejection mode and the sub-combustion mode by adjusting the coupling effect of the large flow rocket, the small flow rocket and the tail nozzle.

Description

Technical Field

[0001] The present invention relates to the field of aerospace power technology, and in particular to an adaptive controllable jet ramjet combination engine and a working method and application thereof. Background Art

[0002] With the development of aerospace technology, the aerospace tools for carrying out satellite launches, deep space exploration and other aerospace missions are still multi-stage chemical launch vehicles. However, rockets have the disadvantages of low specific impulse performance and high cost, which greatly limits the frequency and scale of aerospace activities and cannot meet the growing demand for entering and using space. In order to provide a safe, reliable and economical carrier for aerospace missions, it is necessary to consider combining rockets with other air-breathing propulsion systems to improve the specific impulse and operability of the aircraft. In recent years, scramjet engine technology has made a series of major breakthroughs and has shifted from the principle exploration / key technology research stage to the engineering development stage. In the propulsion system roadmap released by NASA in 2012, the rocket-based combined cycle (RBCC) combining rockets and ramjet engines was listed as a priority development target in the field of air-breathing propulsion systems.

[0003] The RBCC engine is a combination of a high-specific impulse, low-thrust-to-weight ratio ramjet engine and a low-specific impulse, high-thrust-to-weight ratio rocket engine in the same flow channel, forming a new thermodynamic cycle system that gives full play to the performance characteristics of the ramjet and rocket engines, so that the integrated engine can have good working performance in a wide range of speeds and airspaces. During the acceleration process, the RBCC engine will adopt different working modes to adapt to different flight Mach numbers, such as Figure 5 As shown, they include: ejection mode, subsonic ramjet mode, scramjet mode and pure rocket mode.

[0004] Ejection mode (takeoff to Ma2+), that is, working in the normal start of the ramjet engine inlet. In this working mode, the rocket engine remains in the on state, and the high-temperature, high-speed rocket jet introduces external air into the engine flow channel through suction and shearing. As the flight speed increases, the mainstream ejection effect weakens, the ramjet effect of the incoming flow gradually increases, and the ramjet effect begins to replace the ejection effect as the determining factor. The rocket jet and the ramjet airflow are mixed, and secondary combustion is carried out in the combustion chamber to increase the combustion chamber pressure to generate additional thrust. Compared with pure rocket thrust, the RBCC engine will obtain a certain thrust gain through the ejection mode, which is 10% in the takeoff stage and can reach 100% when accelerating to the ramjet mode relay.

[0005] In the subsonic ramjet mode (Ma2-6), the engine inlet has been started. The air flow is compressed by the shock wave system in the inlet and reduced to subsonic speed at the entrance of the combustion chamber, and subsonic combustion is organized in the combustion chamber. Under the inflow conditions of flight Mach number 2-4, considering the reasons of aircraft acceleration, maintaining low temperature and stable combustion of the engine, and improving ignition performance, the small rocket in the flow channel of the combustion chamber can be kept in the open state.

[0006] In the scramjet mode (Ma6~8+), the total temperature of the incoming flow reaches above 1700K, and the engine combustion chamber is no longer suitable for organizing subsonic combustion. On the one hand, excessive compression of the inlet will cause a sharp drop in the total pressure of the incoming flow; on the other hand, strong compression will cause the static temperature of the airflow at the inlet of the combustion chamber to be higher, and the dissociation effect of combustion will lead to a decrease in heat release efficiency. Therefore, supersonic combustion is organized in the combustion chamber to obtain better thrust and specific impulse performance.

[0007] Pure rocket mode (Ma>8+), at this time, the air density gradually decreases, and the scramjet cannot provide a good thrust gain. Under this condition, the air inlet is completely closed, and the rocket engine works at high power to provide power for the aircraft until the aircraft is sent into the predetermined orbit.

[0008] The United States began developing RBCC engines in the 1960s, and has launched three development booms in the 1960s, 1990s, and early 21st century to date.

[0009] The United States has implemented a series of reusable launch vehicle programs since the 1960s. This stage was mostly for feasibility exploration research. The engine structure was simple and the working range was narrow. In this first research boom, the concept of RBCC was proposed, and research proved that RBCC has more advantages than pure rocket engines, and has important research value in the development of future orbital vehicles. With the support of NASA, DARPA and the Air Force, the United States has carried out large-scale, in-depth and detailed research on RBCC engine technology, mainly focusing on the ejection mode and subcombustion mode of RBCC. In the 1960s, Marquardt and other research institutions carried out RBCC engine research with the support of NASA's Reusable Space Transportation System Research Program (RLV). The application directions include high-speed aircraft, reusable launch vehicles, etc. Typical engines are ejector ramjet (ERJ) and supercharged ejector ramjet (SERJ) engines.

[0010] At the end of the 20th century, NASA proposed the Advanced Space Transportation Program (ASTP) and the Integrated Space Transportation Program (ISTP), planning to develop the third-generation reusable launch technology in the next 25 years, with the aim of improving the performance of the third-generation reusable launch vehicle, reducing the launch and maintenance costs, and striving to achieve the flight of space transportation. RBCC engines are the main power research direction of reusable launch vehicles. Typical engines include Aerojet's Strutjet engine, Rocketdyne's A5 engine, Green Research Center's GTX engine and I STAR engine, among which the GTX aircraft launch rocket is installed on the engine side wall, forming an integrated configuration with the ramjet combustion chamber, and using the aircraft forebody for pre-compression; I STAR is the power of the X-43B, based on the Strutjet engine, using a variable geometry inlet and a fixed geometry tail nozzle, and installing multiple struts in the flow channel, and the main rocket is installed in the strut. Through the research of these typical RBCC engines, the United States has achieved the transformation from key technology research and performance research to engineering integrated demonstration and verification.

[0011] Since the beginning of the 21st century, the third wave of research on RBCC application solutions has begun. From 2002 to 2010, the U.S. Air Force continued to conduct RBCC engine application assessments. In the "Technology Horizon - Air Force Science and Technology Development Vision 2010-2030", the hypersonic space vehicle with RBCC engine as the second-stage power was planned as both an ISR / strike configuration vehicle and an entry space vehicle. In 2012, the NASA Technology Roadmap Steering Committee, the Aeronautics and Astronautics Engineering Bureau and the U.S. Academy of Sciences released the "NASA Space Technology Roadmap and Priorities: Restoring NASA's Technological Advantage and Paving the Way for a New Era in Space" report. RBCC is still the priority power system for the development of reusable launch vehicles in the United States.

[0012] Relevant EU countries also carried out the development of RBCC engines simultaneously. In 2003, France launched the LEA flight test project and has continued to this day. In 2005, the European Space Agency formulated the Long-term Advanced Propulsion Concepts and Technologies Research Program (LAPCAT), which mainly carried out the key technologies and aircraft concept designs of RBCC and TBCC. Propulsion system and aircraft analysis and research were carried out for intercontinental goals. From 2008 to 2009, the European Space Agency continued to carry out the demonstration design of RBCC aircraft in LAP-CAT-II. Through demonstration analysis, it is believed that the RBCC aircraft can meet both hypersonic cruise and orbital flight, and wind tunnel tests and small-scale flight tests have been carried out.

[0013] Japan's RBCC engine research began in 1992 and entered a high tide period when the Japan Aerospace Exploration Agency (JAXA) officially launched the research on combined cycle engines in 2003. The ejection rocket of the E3-RBCC engine used by the Japan Aerospace Exploration Agency is located on the upper wall of the isolation section, and the overall structure of the inner flow channel is similar to that of the scramjet engine. According to public literature, the Japan Aerospace Exploration Agency has conducted a series of direct connection and free jet test studies on the ejection mode, subramjet mode (Ma4~6) and scramjet mode (Ma8) of the E3-RBCC engine. In the future, the Japan Aerospace Exploration Agency will focus on the technical demonstration and verification of the RBCC engine. It plans to carry out autonomous flight tests of a 20m-long aircraft with a hydrocarbon-fueled RBCC engine as the first-stage power from 2019 to 2029 to evaluate its two-stage orbital entry and reusability capabilities. Ultimately, the goal is to achieve a low-Earth orbit carrying capacity of 10 passengers or several tons by 2039.

[0014] The 31st Institute of Aerospace in China began to track and analyze foreign research on RBCC engines in the 1970s, and carried out related research in the 1990s. It has conducted Ma1.5-6 tests on the scramjet mode and verified the engine performance. Northwestern Polytechnical University is the most active in RBCC research. It has carried out systematic research on wide-range full-flow channel matching design technology, wide inflow condition organization and flame stabilization technology, and multi-mode smooth transition technology. At present, the development of RBCC free jet prototype and aircraft / engine integrated scaled integrated prototype has been completed, verifying the engine full-flow channel design, modal transition and integrated performance. The 11th Institute of the Sixth Academy of Aerospace Science and Technology has conducted a detailed study on the various working modes of the engine and established an integrated performance calculation model. The National University of Defense Technology has carried out a series of ejection mixing mechanism studies around the ejection mode and established an ejection mode performance prediction model.

[0015] By comparing with the research progress abroad, my country's research progress on RBCC is close to the world's advanced level, but flight test research has not yet been carried out, and there is still a certain gap with its American counterparts.

[0016] The ejection mode of the RBCC engine was proposed to solve the problem of insufficient thrust caused by the weak ramjet capability under low-speed conditions. However, the basic principle of supersonic ejectors at low speeds shows that it is difficult for the engine to achieve both a high ejection ratio and a high compression ratio by ejection, which also brings difficulties to the improvement of the engine thrust and specific impulse performance. For the acceleration process of the aircraft, the acceleration capability (effective specific impulse) caused by the difference between the engine thrust and the aircraft drag is very critical. Although the specific impulse gain of a large-flow rocket is small under low Mach numbers, it has an advantage due to its high effective specific impulse. However, the current combination schemes in the combustion chamber basically use small-flow rockets due to space limitations. Summary of the invention

[0017] In view of the technical problems existing in the above-mentioned background technology, the present invention proposes an adaptive controllable jet ramjet combination engine and its working method and application, in which rockets are installed in the flow channel in the RBCC combustion chamber and on the outside of the tail nozzle, and the high thrust and effective specific impulse required by the aircraft during the acceleration process in the ejection mode and the subcombustion mode are met by adjusting the coupling effect between the large-flow rocket, the small-flow rocket and the tail nozzle.

[0018] In order to solve the above technical problems, the present invention provides an adaptive controllable jet ramjet combination engine, including an air inlet, a combustion chamber and a tail nozzle; the air inlet, the combustion chamber and the tail nozzle are connected end to end in sequence; the engine also includes a small flow rocket and a large flow rocket; the combustion chamber includes a combination section and a mixed combustion section; the small flow rocket is matched and installed inside the combination section; the mixed combustion section is located downstream of the combination section, and in the mixed combustion section, the rocket plume ejected by the small flow rocket can be mixed with the incoming air from the air inlet; the large flow rocket is matched and installed outside the tail nozzle On the other side, the nozzle outlet of the large-flow rocket is connected with the internal flow channel of the tail nozzle; when the large-flow rocket is started under the flight conditions of Mach number Ma0-4, its rocket plume can promote the formation of the aerodynamic throat in the tail nozzle; the tail nozzle is matched with a rotating adjustment plate installed at the part connected to the nozzle outlet of the large-flow rocket; under different Mach numbers of the incoming flow at the engine inlet, the flow channel between the large-flow rocket and the tail nozzle is opened and closed by adjusting the rotating adjustment plate, and the small-flow rocket and the large-flow rocket meet the thrust and specific impulse requirements of the engine in different speed ranges by adjusting the rocket flow.

[0019] The adaptive controllable jet ramjet combination engine, wherein: the rotating adjustment plate is in a horizontal state in a normal state. When the high-flow rocket is turned on, the rocket plume of the high-flow rocket is sprayed into the tail nozzle. At this time, the rotating adjustment plate rotates from the original horizontal position to an inclined state, thereby closing the rocket plume of the high-flow rocket.

[0020] The adaptive controllable jet ramjet combination engine, wherein: the small flow rocket is inserted into the center of the main flow channel from the side wall of the combustion chamber and fixedly installed.

[0021] A method for operating an adaptive controllable jet ramjet engine, characterized in that it mainly comprises the following steps:

[0022] (1) When the combined engine is operating in ejection mode

[0023] When the engine is in a flight Mach number of Ma0-2, sufficient secondary flow is introduced into the engine from the outside through the injection effect of the small-flow rocket. The secondary flow is mixed with the small-flow rocket jet in the mixed combustion section of the combustion chamber and secondary combustion is performed to increase the engine thrust, and the large-flow rocket outside the tail nozzle is turned on. By adjusting the rotating adjustment plate installed at the connection between the tail nozzle and the outlet end of the large-flow rocket, the jet of the large-flow rocket enters the inner flow channel of the tail nozzle; the rocket plume of the large-flow rocket can adjust the flow rate according to the flight conditions to meet the high thrust demand of the engine at the low-speed end and optimize the effective specific impulse of the engine; the rocket plume of the large-flow rocket is conducive to causing congestion of the flow field and promoting the formation of the aerodynamic throat, which can improve the combustion performance of the mixed combustion section of the combustion chamber;

[0024] (2) When the combined engine is operating in the sub-combustion mode

[0025] When the engine is in the flight Mach number of Ma2-4, keep the high-flow rocket open;

[0026] When the engine is in the flight Mach number of Ma4~8+, the air inlet works normally and provides sufficient air flow in the combustion chamber. At this time, the large-flow rocket and the small-flow rocket are closed, and the rotating adjustment plate is closed. The geometric throat of the combustion chamber outlet can improve the engine's dual-mode sub-combustion performance under the Mach number Ma 4~8+ inflow condition. When the engine is in the Mach number Ma 4~8+ condition, the engine's combustion organization is similar to that of the dual-mode scramjet engine, by injecting fuel into the combustion chamber and mixing and burning it with oxygen in the inflow air;

[0027] (3) When the combined engine operates in pure rocket mode

[0028] When the engine reaches the flight Mach number Ma8+, the air inlet will be closed and the high-flow rocket will be turned on again to provide sufficient power for the engine through the rocket plume of the high-flow rocket.

[0029] The working method of the adaptive controllable jet ramjet combination engine, wherein: in the step (2), when the engine is in a flight Mach number of Ma2 to 4, the switch of the small flow rocket can be selected according to whether it is necessary to ensure the combustion stability and ignition performance of the combustion chamber under actual low Mach number flight conditions.

[0030] The invention discloses an application of an adaptive controllable jet ramjet combination engine in an aircraft.

[0031] By adopting the above technical solution, the present invention has the following beneficial effects:

[0032] The present invention installs a large-flow rocket on the outside of the tail nozzle, and turns on the large-flow rocket under low Mach number flight conditions. The rocket plume of the large-flow rocket can form an aerodynamic throat in the tail nozzle to improve the combustion performance of the combustion chamber. The large-flow rocket can meet the high thrust demand of the engine at the low-speed end, and can enable the engine to pass through the low-speed end quickly, thereby making the effective specific impulse of the engine higher.

[0033] Meanwhile, the main effects of the present invention are embodied in the following aspects:

[0034] (1) The present invention can cause flow congestion in the flow field and generate aerodynamic throat by utilizing the change of the tail nozzle geometric structure in the ejection mode and subcombustion mode (flight Mach number Ma0-4) and introducing a large flow rocket plume to the combustion chamber outlet, which is beneficial to the ignition and flame stabilization of the engine combustion chamber and improves the combustion performance. In addition, the introduction of an adjustable rocket jet can provide additional thrust for the combined engine in the acceleration phase of performing the carrying mission, meet the demand for high thrust under the low-speed working condition of the combined engine, and improve the effective specific impulse of the engine, so that it can quickly pass through the low-speed end.

[0035] (2) In the subsonic and scramjet modes (flight Mach number Ma4-8), the present invention simultaneously closes the small rocket jet in the combustion chamber and the large flow rocket outside the tail nozzle, and adjusts its own geometric structure to increase the area expansion ratio of the tail nozzle, so that the airflow can fully expand and do work, thereby improving the engine specific impulse performance.

[0036] (3) The present invention closes the air inlet in pure rocket mode (flight Mach number Ma8+) and starts the rocket engine, and only uses the high-power rocket mainstream in the combustion chamber to provide sufficient power for the engine.

[0037] The adaptive controllable jet ramjet combined engine of the present invention can operate in a wide range of flight Mach numbers (Ma0-25+, earth-to-earth round-trip) or (Ma0-8+, hypersonic cruise), and has high research value in the field of new air-breathing combined cycle engine design. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 This is a structural principle diagram of the adaptive controllable jet ramjet combination engine of the present invention;

[0040] Figure 2 It is a working flow field diagram of the adaptive controllable jet ramjet combination engine of the present invention under the working condition of the flight Mach number Ma0-4;

[0041] Figure 3 It is a working flow field diagram of the adaptive controllable jet ramjet combination engine of the present invention under the condition of flight Mach number of Ma4~8+;

[0042] Figure 4 It is the working flow field diagram of the adaptive controllable jet ramjet combination engine of the present invention under the flight Mach number Ma8+ working condition;

[0043] Figure 5 Schematic diagram of typical working modes of existing RBCC engines. DETAILED DESCRIPTION

[0044] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The present invention is further explained below in conjunction with specific implementation modes.

[0047] like Figure 1 As shown, the adaptive controllable jet ramjet combination engine of the present invention includes an air inlet 1, a combustion chamber 2, a tail nozzle 3, a small flow rocket 4 and a large flow rocket 5.

[0048] The air inlet 1, the combustion chamber 2 and the tail nozzle 3 are connected end to end in sequence; the air inlet 1 is used to input incoming air; and the tail nozzle 3 is a variable geometry tail nozzle.

[0049] The combustion chamber 2 is used to achieve mixed combustion of incoming air and injected fuel, which plays a decisive role in the performance of the engine; wherein, the combustion chamber 2 includes a combination section 21 and a mixing combustion section 22; the combination section 21 is used to install a small-flow rocket 4, and the mixing combustion section 22 is the remaining downstream part of the combustion chamber 2 where the small-flow rocket 4 is not installed, and the rocket plume ejected by the small-flow rocket 4 in the mixing combustion section 22 can be mixed with the incoming air coming from the air inlet 1.

[0050] The small flow rocket 4 is matched and installed inside the combination section 21 of the combustion chamber 2, specifically, it is inserted and fixedly installed from the side wall of the combustion chamber 2 to the center of the main flow channel. Among them, in this embodiment, the combustion chamber 2 adopts a square combustion chamber, and for the circular combustion chamber, the small flow rocket 4 is also installed from the side wall of the combustion chamber 2 to the center of the flow channel.

[0051] The large-flow rocket 5 is matched and installed on the outside of the tail nozzle 3, and the nozzle outlet of the large-flow rocket 5 is connected with the internal flow channel of the tail nozzle 3; the large-flow rocket 5 is turned on under the flight conditions of Mach number Ma0-4, and the plume of the large-flow rocket 5 can promote the formation of the aerodynamic throat 6 in the tail nozzle 3 and improve the combustion performance. The large-flow rocket 5 can meet the high thrust demand of the engine at the low-speed end and enable the engine to pass through the low-speed end quickly, so the effective specific impulse of the engine is high.

[0052] The tail nozzle 3 is provided with a rotating adjustment plate 7 on the wall surface of the part connected to the nozzle outlet of the large flow rocket 5. Under different Mach numbers of the incoming flow at the engine inlet, the flow channel between the large flow rocket 5 and the tail nozzle 3 can be opened or closed by adjusting the rotating adjustment plate 7. The small flow rocket 4 and the large flow rocket 5 can meet the thrust and specific impulse requirements of the engine in different speed ranges by adjusting the rocket flow.

[0053] The rotating adjustment plate 7 is in a horizontal state in a normal state. When the large-flow rocket 5 is turned on, the rocket plume of the large-flow rocket 5 can be sprayed into the tail nozzle 3. The rotating adjustment plate 7 is rotated from the original horizontal position to an inclined state to close the rocket plume of the large-flow rocket 5.

[0054] The adaptive controllable jet ramjet engine of the present invention realizes the high performance of the adaptive controllable jet ramjet combination engine of the present invention in a wide speed range (flight Mach number 0 to 8+) through its own coupling effect and reasonable design and adjustment of the tail nozzle 3.

[0055] The working method of the adaptive controllable jet ramjet combined engine based on a large flow rocket of the present invention specifically includes:

[0056] (1) When the engine is operating in ejection mode

[0057] like Figure 2 As shown, when the engine is at a flight Mach number Ma0-2, the adaptive controllable jet ramjet engine of the present invention is turned on, and sufficient secondary flow (air) is injected into the engine from the outside through the injection effect of the small-flow rocket 4. The secondary flow is mixed with the rocket plume of the small-flow rocket 4 in the mixed combustion section 22 in the combustion chamber 2 and secondary combustion is performed to increase the thrust of the engine, and the large-flow rocket 5 outside the tail nozzle 3 is turned on, and the rotating adjustment plate 7 is adjusted to make the rocket plume of the large-flow rocket 5 enter the inner flow channel of the tail nozzle 3. The rocket plume of the large-flow rocket 5 can adjust the flow rate according to the flight conditions to meet the high thrust demand of the engine at the low-speed end and optimize the effective specific impulse of the engine. At the same time, the rocket plume of the large-flow rocket 5 is conducive to causing congestion of the flow field and promoting the formation of the aerodynamic throat 6 (caused by the congestion caused by the airflow of the large-flow rocket 5), which can improve the combustion performance of the mixed combustion section 22 of the combustion chamber 2 of the engine.

[0058] (2) When the engine is operating in the sub-combustion mode

[0059] When the engine is at a flight Mach number of Ma2 to 4, keep the high-flow rocket on, and select the switch of the low-flow rocket 4 according to whether it is necessary to ensure the combustion stability and ignition performance of the combustion chamber under actual low Mach number flight conditions.

[0060] like Figure 3 As shown, under the flight Mach number (Ma4~8+), due to the increase in the Mach number, the ramjet effect is enhanced, the air inlet 1 can work normally and provide a sufficient flow of air in the combustion chamber, and it is no longer necessary to use the induced effect of the small flow rocket 4 to introduce air from the outside into the engine; at this time, the large flow rocket 5 and the small flow rocket 4 are closed, and the rotating adjustment plate 7 of the variable tail nozzle 3 is closed, and the geometric throat 8 at the combustion chamber outlet (the aerodynamic congestion effect disappears after the large flow rocket 5 is closed, and the flow field congestion is formed by the throat of the combustion chamber 2's own geometric structure).

[0061] It can improve the dual-mode scramjet performance of the engine under Mach number Ma 4~8+ inflow conditions. When the engine is in Mach number Ma 4~8+ conditions, the combustion organization of the engine is similar to that of the dual-mode scramjet engine, by injecting fuel into the combustion chamber and mixing and burning it with oxygen in the inflowing air.

[0062] (3) When the engine is operating in pure rocket mode

[0063] like Figure 4As shown, when the engine is at a flight Mach number of Ma8+, due to the low density of the air in the airspace where the engine is located, the thrust gain obtained by the scramjet is low. At this time, the air inlet 1 is closed and the high-flow rocket 5 is opened again to provide sufficient power for the engine through the rocket plume of the high-flow rocket 5.

[0064] The adaptive controllable jet ramjet combination engine of the present invention can be applied to high-speed cruising flight and earth-to-earth round-trip transport flight. In the high-speed cruising flight target, the pure rocket mode is not activated, and in the earth-to-earth round-trip transport flight target, the pure rocket mode is activated.

[0065] The present invention realizes the high performance of an adaptive controllable jet ramjet combination engine in a wide speed range (flight Mach number 0 to 8+) through the coupling effect of a rocket engine and a ramjet engine and the reasonable design and adjustment of a tail nozzle.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive controllable jet ramjet engine, comprising an air inlet, a combustion chamber and a tail nozzle; the air inlet, the combustion chamber and the tail nozzle are connected end to end in sequence; characterized in that: The engine also includes a small flow rocket and a large flow rocket; The combustion chamber comprises a combination section and a mixed combustion section; the small flow rocket is matched and installed inside the combination section; the mixed combustion section is located downstream of the combination section, and in the mixed combustion section, the rocket plume ejected by the small flow rocket can be mixed with the incoming air from the air inlet; The large-flow rocket is matched and installed on the outside of the tail nozzle, and the nozzle outlet of the large-flow rocket is connected to the inner flow channel of the tail nozzle; when the large-flow rocket is started under the flight condition of Mach number Ma0-4, its rocket plume can promote the formation of the aerodynamic throat in the tail nozzle; The tail nozzle is matched with a rotating adjustment plate installed at the portion where it is connected to the nozzle outlet of the large-flow rocket; under different Mach numbers of the incoming flow at the engine inlet, the flow channel between the large-flow rocket and the tail nozzle is opened and closed by adjusting the rotating adjustment plate, and the small-flow rocket and the large-flow rocket meet the thrust and specific impulse requirements of the engine in different speed ranges by adjusting the rocket flow.

2. The adaptive controllable jet ramjet combination engine according to claim 1, characterized in that: The rotating adjustment plate is in a horizontal state in a normal state. When the high-flow rocket is turned on, the rocket plume of the high-flow rocket is sprayed into the tail nozzle. At this time, the rotating adjustment plate rotates from its original horizontal position to an inclined state, thereby closing the rocket plume of the high-flow rocket.

3. The adaptive controllable jet ramjet combination engine according to claim 1, characterized in that: The small flow rocket is inserted into the center of the main flow channel from the side wall of the combustion chamber and fixedly installed.

4. A method for operating an adaptive controllable jet ramjet combination engine according to any one of claims 1 to 3, characterized in that: The main steps include: (1) When the combined engine is operating in ejection mode When the engine is in a flight Mach number of Ma0-2, sufficient secondary flow is introduced into the engine from the outside through the injection effect of the small-flow rocket. The secondary flow is mixed with the small-flow rocket jet in the mixed combustion section of the combustion chamber and secondary combustion is performed to increase the engine thrust, and the large-flow rocket outside the tail nozzle is turned on. By adjusting the rotating adjustment plate installed at the connection between the tail nozzle and the outlet end of the large-flow rocket, the jet of the large-flow rocket enters the inner flow channel of the tail nozzle; the rocket plume of the large-flow rocket can adjust the flow rate according to the flight conditions to meet the high thrust demand of the engine at the low-speed end and optimize the effective specific impulse of the engine; the rocket plume of the large-flow rocket is conducive to causing congestion of the flow field and promoting the formation of the aerodynamic throat, which can improve the combustion performance of the mixed combustion section of the combustion chamber; (2) When the combined engine is operating in the sub-combustion mode When the engine is in the flight Mach number of Ma2-4, keep the high-flow rocket open; When the engine is in the flight Mach number of Ma4~8+, the air inlet works normally and provides sufficient air flow in the combustion chamber. At this time, the large-flow rocket and the small-flow rocket are closed, and the rotating adjustment plate is closed. The geometric throat of the combustion chamber outlet can improve the engine's dual-mode sub-combustion performance under the Mach number Ma 4~8+ inflow condition. When the engine is in the Mach number Ma 4~8+ condition, the engine's combustion organization is similar to that of the dual-mode scramjet engine, by injecting fuel into the combustion chamber and mixing and burning it with oxygen in the inflow air; (3) When the combined engine operates in pure rocket mode When the engine reaches the flight Mach number Ma8+, the air inlet will be closed and the high-flow rocket will be turned on again to provide sufficient power for the engine through the rocket plume of the high-flow rocket.

5. The operating method of the adaptive controllable jet ramjet combination engine according to claim 4, characterized in that: In the step (2), when the engine is in the flight Mach number of Ma2-4, the switch of the small flow rocket can be selected according to whether it is necessary to ensure the combustion stability and ignition performance of the combustion chamber under the actual low Mach number flight condition.

6. Use of the adaptive controllable ramjet combination engine according to any one of claims 1 to 3 in an aircraft.

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