Multifunctional rotating detonation engine exhaust system with reconfigurable morphology and method of use

Abstract

The present invention discloses a reconfigurable multifunctional rotating detonation engine exhaust system and its use method. The system comprises the following components: an outer ring mounting flange, an inner ring hollow cylinder, an inner ring straight section, an inner ring constriction section, a truncated axisymmetric plug cone, an outer ring constriction section, and an outer ring lip cover. The outer side of the outer ring mounting flange is equipped with a one-way valve, a spark plug mounting hole, and a pressure sensor interface. The inner ring hollow cylinder connects to the inner ring straight section. The inner ring straight section can be connected to either the inner ring constriction section or the truncated plug cone. The outer ring lip cover can be connected to either the outer ring constriction section or the outer ring mounting flange. The components are fastened together by radially threaded bolts. By adding and removing components, the present invention reconfigures the rotating detonation engine exhaust system to achieve seven aerodynamic profiles: short blunt nose, long blunt nose, fixed lip cover / cone constriction, fixed plug cone / cone constriction, throat-free, fixed lip cover half-barrel, and no lip cover plug, facilitating systematic hot-seat testing.

Description

Technical Field

[0001] The invention belongs to the field of rotating detonation engine hot-start test models, and in particular relates to a multifunctional rotating detonation engine exhaust system with reconfigurable form and a use method thereof. Background Art

[0002] Compared to traditional aircraft engines based on a slow combustion process, propulsion systems based on detonation offer significant advantages in thermal engine efficiency. This is because the detonation wave rapidly releases chemical heat, causing a sharp increase in flow parameters and minimal entropy increase after the airflow passes through it. Unlike the Brayton cycle, the ZND cycle, corresponding to the detonation phenomenon, exhibits an additional peak on the pressure-volume diagram under the same initial conditions, typically resulting in an increase in net pressure rise and useful work. To effectively utilize the kilometer-per-second propagation speed of the detonation wave and the strong coupling between the heat release reaction and the shock wave, mainstream detonation engines include oblique detonation engines, pulse detonation engines, and rotating detonation engines. However, the former two often face technical challenges caused by aerodynamic and geometric limitations. In oblique detonation engines, the detonation wave is often induced by an intrusive structure or inclined wall, but this often increases wave resistance and significantly restricts the flight range. In pulse detonation engines, the detonation wave is often triggered by intermittent spark discharges, with the wavefront moving from the closed end of a straight tube to the open end. The operating frequency of a pulse detonation engine is limited to hundreds of hertz by mechanical valves and the gas purge process. In contrast, a rotating detonation engine (RDE) allows the detonation wave to continuously propagate circumferentially even with a single ignition. While pulse detonation engines generate partial negative thrust during a single cycle, RDEs can continuously generate positive thrust. RDEs are expected to bring new technological innovations to the propulsion systems of high-speed aircraft.

[0003] With the increasing demand for low-cost and fast accessibility, the rotating detonation engine has attracted increasing attention from researchers. In order to effectively utilize the characteristics of the rotating detonation engine, such as long fuel residence time, relatively simple and compact structure, and high specific impulse, a suitable exhaust system needs to be connected downstream of the combustion chamber to achieve the purpose of efficient expansion and acceleration of the airflow. However, due to the influence of the periodic shock waves in the combustion chamber, there are also high-frequency periodic flow parameter mutations in the nozzle. In order to clearly define the internal flow channel profile of the exhaust system suitable for the rotating detonation engine, traditional experimental models often need to be processed in multiple sets for separate research, which undoubtedly increases the experimental cost. However, the present invention will fully design the various components of the rotating detonation engine exhaust system based on the principle of interchangeability. By adding or removing straight sections such as plug cones, lip covers, inner and outer rings, and inner and outer ring surface contraction sections, rotating detonation engine exhaust systems of different forms are obtained, thereby completing the spectrum hot state experimental research at a low cost. Summary of the Invention

[0004] The present invention aims to provide a multifunctional rotating detonation engine exhaust system with a reconfigurable configuration. Its components are designed with full interchangeability in mind, allowing for the creation of various rotating detonation engine exhaust system configurations by adding or removing straight sections, such as the plug cone, lip shield, inner and outer rings, and contracted sections on the inner and outer ring surfaces. These configurations include seven types of internal flow channel aerodynamic profiles: short blunt tip, long blunt tip, fixed lip shield / retracted plug cone, fixed plug cone / retracted lip shield, throat-free, fixed lip shield half-barrel, and no lip shield plug. By simply adding or removing components, the present invention allows for systematic and low-cost hot ignition experiments. Initial ignition of the rotating detonation engine is achieved through spark plug mounting holes arranged on the outer ring wall. Dynamic pressure sensor mounting holes arranged on the outer ring wall allow for measurement of the number of detonation wave heads, propagation direction, and propagation frequency of the rotating detonation engine's detonation waves. Pressure transmitter probe mounting holes arranged on the lip shield allow for pressure distribution along the rotating detonation engine exhaust system at different pressure drop ratios and equivalence ratios. The present invention can effectively explore the adaptability of rotating detonation engine exhaust systems of different forms under different thermal working conditions.

[0005] Technical solution: To achieve the above purpose, the technical solution adopted by the present invention is:

[0006] The multifunctional rotating detonation engine exhaust system with reconfigurable form includes an outer ring mounting flange, an inner ring hollow cylinder, an inner ring straight section, an inner ring contraction section, a truncated axisymmetric plug cone, an outer ring contraction section, and an outer ring lip cover:

[0007] The outer ring mounting flange is circumferentially distributed with multiple radial one-way valves extending from the outside to the inside, and a spark plug connection hole is provided on one side of the radial one-way valve and on the outer ring mounting flange; the outer ring mounting flange is detachably connected to the inner ring hollow cylindrical surface;

[0008] The inner ring hollow cylindrical surface has a plurality of through holes uniformly distributed along the circumference of the cylindrical surface of the cylindrical cavity. Under installation conditions, the airflow enters from the inlet of the cylindrical cavity and then radially enters the upstream of the injection end of the rotating detonation engine combustion chamber through the through holes. The inner ring hollow surface is centered and positioned by the cylindrical step and the inner ring straight section, and can be detachably connected.

[0009] The mounting surface dimensions of the inner ring straight section are consistent with those of the inner ring surface contraction section and the truncated axisymmetric plug cone; the inner ring straight section, the inner ring surface contraction section and the truncated axisymmetric plug cone are detachably connected;

[0010] The inner annular surface contraction section can also be connected and fastened to the truncated axisymmetric plug cone through a radial threaded countersunk hole;

[0011] The outer ring surface contraction section and the outer ring mounting flange are detachably connected;

[0012] In addition to being connected to the contraction section of the outer ring surface, the outer ring lip cover can also be directly connected to the outer ring mounting flange; the inner wall surface of the outer ring lip cover is designed by a characteristic line based on the maximum thrust theory, and its outer wall surface is provided with pressure transmitter mounting holes distributed along the axial direction and perpendicular to the normal of the inner wall surface for connecting the pressure transmitter probe.

[0013] Preferably, by adding or subtracting truncated axisymmetric plug cones, outer ring lip covers, straight sections of the inner annular surface, and contracted sections of the outer annular surface, the morphological reorganization of the exhaust system of the rotating detonation engine is achieved, thereby obtaining a short blunt head, a long blunt head, a fixed lip cover / plug cone retracted, a fixed plug cone / lip cover retracted, no throat misalignment, a lip cover fixed half-barrel type, and a lip cover-free plug type with a common inner flow channel aerodynamic profile;

[0014] The short blunt head configuration includes an outer ring mounting flange and an inner ring hollow cylindrical surface;

[0015] The long blunt head configuration includes an outer ring mounting flange, an inner ring hollow cylindrical surface and straight sections such as the inner ring surface;

[0016] The lip cover fixing / plug cone retraction configuration includes an outer ring mounting flange, an inner ring hollow cylinder, an inner ring surface straight section, a truncated axisymmetric plug cone, an outer ring surface retraction section and an outer ring lip cover;

[0017] The plug cone fixed / lip cover retracted configuration includes an outer ring mounting flange, an inner ring hollow cylindrical surface, an inner ring surface straight section, an inner ring surface retracted section, a truncated axisymmetric plug cone and an outer ring lip cover;

[0018] The throat non-dislocation configuration includes an outer ring mounting flange, an inner ring hollow cylindrical surface, an inner ring surface straight section, an inner ring surface contraction section, a truncated axisymmetric plug cone, an outer ring surface contraction section and an outer ring lip cover;

[0019] The lip cover fixed semi-barrel configuration includes an outer ring mounting flange, an inner ring hollow cylindrical surface, an outer ring surface contraction section and an outer ring lip cover;

[0020] The lipless plug-type configuration includes an outer ring mounting flange, an inner ring hollow cylinder, an inner ring surface straight section, an inner ring surface contraction section, a truncated axisymmetric plug cone and an outer ring surface contraction section.

[0021] Preferably, a dynamic pressure sensor mounting hole is provided on the outer ring mounting flange, which is connected to the dynamic pressure sensor through the dynamic pressure sensor mounting hole, so as to sense the number of detonation wave heads and the detonation wave propagation frequency in the rotating detonation engine; a pressure transmitter mounting hole is provided on the outer ring lip cover, which is connected to the pressure transmitter probe through the pressure transmitter mounting hole, so as to sense the pressure distribution along the outer lip cover wall under different pressure drop ratios and equivalence ratios.

[0022] Preferably, the bottom of the outer ring mounting flange has a cylindrical step, and the depth and radius of the cylindrical step are consistent with the size of the mounting edge of the inner ring hollow cylindrical surface; the outer ring mounting flange and the inner ring hollow cylindrical surface are connected by an axial threaded countersunk hole; the inner ring hollow surface is connected by the cylindrical step and the inner ring straight section through radial threaded countersunk holes; the connection and fastening of the inner ring straight section to the inner ring surface contraction section and the truncated axisymmetric plug cone are all through radial threaded countersunk holes. The interior of the truncated axisymmetric plug cone is weighted by multi-step step countersunk holes, and its outer wall surface is designed by characteristic lines based on the maximum thrust theory; the outer ring surface contraction section and the outer ring mounting flange are centered and positioned by the cylindrical step, and are connected by circumferentially evenly distributed radial threaded countersunk holes;

[0023] A method for using a multifunctional rotating detonation engine exhaust system with reconfigurable form: high-pressure air first enters the inlet of the cylindrical cavity of the inner ring hollow cylinder and then enters the rotating detonation combustion chamber pressure stabilization cavity through the radial through hole. After passing through the contraction section of the rotating detonation combustion chamber injection port, the airflow is accelerated. After passing through the expansion section of the rotating detonation combustion chamber injection port, the airflow is further expanded and accelerated. The airflow interacts with the fuel injected from the radial fuel jet holes in the injection port throat to form relatively uniform atomized particles, thereby expanding the contact area between the air and fuel droplets, which is beneficial to ignition and flame stabilization.

[0024] The radial one-way valve installed on the outside of the outer ring mounting flange ensures that the fuel flows in radial injection from the outside to the inside, and the flow area from the radial one-way valve to the radial jet hole gradually decreases; a spark plug is installed through the spark plug connecting hole, and the spark plug forms a high-voltage arc in the expansion section downstream of the injection port through a high-voltage discharge process, directly triggering the detonation phenomenon; with the help of the asymmetry of the arc generated by the spark plug, a strong and a weak detonation wave propagating in opposite directions is generated, and the detonation wave system is adaptively controlled through multiple double-wave collision processes, and finally a stable unidirectional detonation wave propagation mode is obtained.

[0025] Beneficial effect: The multifunctional rotating detonation engine exhaust system with reconfigurable morphology provided by the present invention can realize the morphological reconfiguration of the rotating detonation engine exhaust system by adding or reducing straight sections such as plug cones, lip covers, inner and outer rings, and contraction sections of inner and outer ring surfaces, thereby obtaining seven types of inner flow channel aerodynamic surfaces, including short blunt head, long blunt head, fixed lip cover / retracted plug cone, fixed plug cone / retracted lip cover, no throat misalignment, fixed lip cover half-barrel type, and no lip cover plug type, which is helpful for conducting spectral thermal experimental research on the exhaust system of the rotating detonation engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 (a) is a three-dimensional diagram of the throat-free configuration of the multifunctional rotating detonation engine exhaust system with reconfigurable morphology according to the present invention; Figure 1(b) is a meridian cross-sectional view of a throat-free configuration of the multifunctional rotating detonation engine exhaust system with a reconfigurable form according to the present invention;

[0027] Figure 2 (a) is a three-dimensional diagram of a short blunt-end configuration of a multifunctional rotating detonation engine exhaust system with a reconfigurable form according to the present invention; Figure 2 (b) is a meridian cross-sectional view of a short blunt-end configuration of the multifunctional rotating detonation engine exhaust system with a reconfigurable form according to the present invention;

[0028] Figure 3 (a) is a three-dimensional diagram of the long blunt-end configuration of the multifunctional rotating detonation engine exhaust system with reconfigurable morphology of the present invention; Figure 3 (b) is a meridian cross-sectional view of a long blunt-nosed configuration of the multifunctional rotating detonation engine exhaust system with a reconfigurable form according to the present invention;

[0029] Figure 4 (a) is a three-dimensional diagram of the lip cover fixed / plug cone retracted configuration of the multifunctional rotating detonation engine exhaust system with reconfigurable form of the present invention; Figure 4 (b) is a meridian cross-sectional view of the lip cover fixed / plug cone retracted configuration of the multifunctional rotating detonation engine exhaust system of the present invention;

[0030] Figure 5 (a) is a three-dimensional diagram of the plug cone fixed / lip cover retracted configuration of the multifunctional rotating detonation engine exhaust system with reconfigurable form of the present invention; Figure 5 (b) is a meridian cross-sectional view of the plug-cone fixed / lip-cover retracted configuration of the multifunctional rotating detonation engine exhaust system of the present invention;

[0031] Figure 6 (a) is a three-dimensional diagram of a lip cover fixed half-barrel configuration of a multifunctional rotating detonation engine exhaust system with a reconfigurable form according to the present invention; Figure 6 (b) is a meridian cross-sectional view of a lip cover fixed half-barrel configuration of the multifunctional rotating detonation engine exhaust system with a reconfigurable form of the present invention;

[0032] Figure 7 (a) is a three-dimensional diagram of a lipless plug-type configuration of a multifunctional rotating detonation engine exhaust system with a reconfigurable form according to the present invention; Figure 7 (b) is a meridian cross-sectional view of a lipless plug-type configuration of the multifunctional rotating detonation engine exhaust system with a reconfigurable form of the present invention;

[0033] Figure 8The present invention provides a functional zoning diagram of a throat-free configuration of a reconfigurable multifunctional rotary detonation engine exhaust system, and indicates the gas flow direction. The functional areas include an air axial intake / radial diversion and rectification area (8), a rotary detonation engine combustion chamber injection area contraction section (9), a rotary detonation engine combustion chamber throat fuel injection section (10), a rotary detonation engine combustion chamber injection area expansion section (11), a rotary detonation engine combustion chamber main body (12), a rotary detonation engine nozzle contraction section (13), a rotary detonation engine nozzle expansion section (14), and a rotary detonation engine outflow area (15).

[0034] Figure 9 Schematic diagram of the flow field structure in a typical non-premixed rotating detonation engine exhaust system, including a detonation wave (16), a strip-shaped injection triangle (17), a contact discontinuity (18), a triple wave point (19), a shear layer (20), and an induced shock wave (21).

[0035] Figure 10 (a) The geometric structure of the rear body recirculation zone of the short blunt nose configuration of the multifunctional rotating detonation engine exhaust system of the present invention;

[0036] Figure 10 (b) The geometric structure of the rear body recirculation zone of the long blunt nose configuration of the multifunctional rotating detonation engine exhaust system of the present invention;

[0037] Figure 10 (c) The geometric structure of the rear body recirculation zone of the lip cover fixed half-barrel configuration of the multifunctional rotating detonation engine exhaust system with reconfigurable form of the present invention;

[0038] Figure 11 (a) The geometric structure of the rear body recirculation zone of the throat non-displacement configuration of the multifunctional rotating detonation engine exhaust system of the present invention;

[0039] Figure 11 (b) The geometric structure of the rear body recirculation zone of the lip cover fixed / plug cone retracted configuration of the multifunctional rotating detonation engine exhaust system of the present invention;

[0040] Figure 11 (c) The geometric structure of the rear body recirculation zone of the plug-cone fixed / lip-cover retracted configuration of the multifunctional rotating detonation engine exhaust system of the present invention;

[0041] Figure 11 (d) is the geometric structure of the rear body recirculation zone of the lipless cover plug configuration of the multifunctional rotating detonation engine exhaust system with reconfigurable form of the present invention.

[0042] In the figure: outer ring mounting flange 1, inner ring hollow cylinder 2, inner ring surface straight section 3, inner ring surface contraction section 4, truncated axisymmetric plug cone 5, outer ring surface contraction section 6, outer ring lip cover 7. DETAILED DESCRIPTION

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0044] In this patent, “ / ” is a synonym for “and”, etc., indicating that the two states described before and after “ / ” exist at the same time.

[0045] Combine Figure 1 (a) and Figure 1 As shown in (b), the present invention discloses a throat-free configuration of a multifunctional rotating detonation engine exhaust system with a reconfigurable shape, comprising the following components:

[0046] Part 1, outer ring mounting flange;

[0047] Component 2, inner ring hollow cylinder;

[0048] Component 3, inner annular surface straight section;

[0049] Component 4, inner annular surface contraction section;

[0050] Component 5, truncated axisymmetric plug cone;

[0051] Component 6, outer annular surface contraction section;

[0052] Component 7, outer lip cover;

[0053] The outer ring mounting flange 1 and the inner ring hollow cylinder 2 are centered and positioned by cylindrical steps, and are connected and fastened by axial threaded countersunk holes evenly distributed along the circumference. The inner ring hollow cylinder 2 and the inner ring surface straight section 3 are centered and positioned by cylindrical steps, and are connected and fastened by radial threaded countersunk holes evenly distributed along the circumference. The inner ring surface straight section 3 can be centered and positioned not only with the inner ring surface contraction section 4, but also with the truncated axisymmetric plug cone 5. The inner ring surface straight section 3 is connected and fastened not only with the inner ring surface contraction section 4 by means of radial threaded countersunk holes evenly distributed along the circumference, but also with the truncated axisymmetric plug cone 5 by means of radial threaded countersunk holes evenly distributed along the circumference. The outer ring mounting flange 1 can be centered and positioned not only with the outer ring surface contraction section 6 by means of cylindrical steps, but also with the outer ring lip cover 7 by means of cylindrical steps. The outer ring mounting flange 1 is not only connected and fastened to the outer ring surface contraction section 6 by means of circumferentially uniformly distributed radial threaded countersunk holes, but is also connected and fastened to the outer ring lip cover 7 by means of radial threaded countersunk holes.

[0054] The outer ring mounting flange 1 has holes evenly distributed around its circumference, allowing it to be mounted to the wind tunnel connection section using bolts and nuts. Check valves are evenly distributed around the outer wall of the outer ring mounting flange 1 for connecting to the fuel supply line. The outer wall of the outer ring mounting flange 1 has holes for connecting spark plugs and a dynamic pressure sensor. The inner wall of the outer ring mounting flange 1 contains a smoothly transitioned raised structure that, together with the outer wall of the inner ring's hollow cylindrical surface, forms the contraction-expansion channel for the injection section of the rotating detonation combustion chamber. The radial hole where the check valve is located on the outer ring mounting flange 1 has a sudden contraction in radius from the outside to the inside to control the fuel flow rate.

[0055] The inner hollowed-out cylindrical surface 2 is uniformly distributed with through-holes along its circumference, guiding airflow into the upstream injection section of the rotating detonation combustion chamber. The unhollowed-out portion supports downstream components. The only flow path for air entering the inner hollowed-out cylindrical surface 2 is through the cylindrical counterbore inlet and out through the through-holes. Downstream components of the inner ring are not connected to the inner hollowed-out cylindrical surface 2.

[0056] The straight section 3 of the inner ring surface serves to connect the upstream inner ring hollow cylinder 2 and the downstream inner ring surface contraction section 4 or the truncated axisymmetric plug cone 5. The use of the annular cylinder can also effectively reduce weight and reduce the warping deformation of the inner ring surface caused by gravity.

[0057] The inner and outer annular converging sections 4 and 6, in a throat-free configuration, form the converging section of the rotating detonation engine nozzle, stabilizing the combustion chamber pressure. Axially misaligning the inner and outer annular converging sections 4 and 6 effectively alters the pattern of area variation along the nozzle, thereby controlling the axial force of the rotating detonation engine.

[0058] The outer nozzle expansion section of the truncated, axisymmetric plug cone 5 is designed using characteristic lines based on maximum thrust theory. The right end surface is a circular plane. Airflow expands and accelerates after passing through the plug cone surface, and further accelerates after passing through the expansion fan emitted by the right end surface. This right end surface forms a recirculation zone, forming an aerodynamic tail cone.

[0059] The outer annular constriction section 6 connects the upstream outer ring mounting flange 1 and the downstream outer ring lip 7. In a throat-free configuration, the outer annular constriction section 6 and the inner annular constriction section form the constriction section of the rotating detonation engine nozzle, stabilizing the combustion chamber pressure. Axially misaligning the outer annular constriction section 6 with the inner annular constriction section 4 effectively alters the pattern of area variation along the nozzle, thereby controlling the axial force of the rotating detonation engine.

[0060] The inner nozzle expansion section of the outer lip shield 7 is designed using characteristic lines based on maximum thrust theory. The wall's along-the-wall steady-state pressure measurement hole is a cylindrical countersunk hole for mounting a pressure transmitter probe. In a throat-free configuration, the outer lip shield 7 and the truncated axisymmetric plug cone 5 together form the exhaust system expansion section of the rotating detonation engine.

[0061] The contraction and expansion ratios of the rotating detonation combustion chamber injection section, formed by the outer ring mounting flange 1 and the inner ring hollow cylinder 2, are designed based on the one-dimensional compressible flow rate theorem. The expansion ratio of the rotating detonation combustion chamber can achieve an inlet Mach number of the aerosol mixture within the range of 1.2-2.0. The fuel injection holes in the throat of the combustion chamber injection section are perpendicular to the inner wall surface of the outer ring mounting flange 1, enhancing the interaction between the airflow and the droplets and increasing the degree of droplet breakup. The total area of ​​the fuel injection holes in the combustion chamber injection section is calculated based on the incompressible Bernoulli principle, and the aperture size is based on an experimental empirical relationship.

[0062] The fuel injection holes uniformly distributed around the outer mounting flange 1 gradually decrease in diameter from the outside to the inside, providing pressure stabilization and flow regulation. The total area of ​​the uniformly distributed through-holes on the inner hollow cylindrical surface 2 must be larger than the annular throat area of ​​the rotating detonation combustion chamber's injection section, thereby stabilizing and rectifying the inlet high-pressure air.

[0063] The radial projections of the fuel injection holes, evenly distributed around the outer ring mounting flange 1, correspond to the solid wall of the inner ring hollow cylinder. After entering the inner ring surface at the throat of the rotating detonation combustion chamber, the fuel impacts the wall, causing splashing, effectively promoting the breakup of the fuel liquid column into large droplets. Subsequently, the interaction between the mainstream air flow and the large droplets effectively promotes the breakup of large fuel droplets into small droplets. Furthermore, the spatial positioning of the fuel injection holes in the outer ring mounting flange 1 relative to the inner wall effectively prevents the backflow of the combustible mixture into the upstream high-pressure air line.

[0064] The annular cavity formed by the outer mounting flange 1 and the inner hollow cylindrical surface 2 effectively limits the circumferential propagation of the detonation wave, which then induces a reverse-propagating oblique shock wave. Because the inner hollow cylindrical surface 2 is circumferentially distributed with through-holes, the intensity of the reverse-propagating oblique shock wave is weakened by lateral expansion, thus preventing air from being blocked from injection due to the high-pressure zone of the detonation.

[0065] The contact surface between the outer ring surface contraction section 6 and the outer ring mounting flange 1 is engraved with a sealing ring groove to improve airtightness. The contact surface between the outer ring surface contraction section 6 and the outer ring lip cover 7 is engraved with a sealing ring groove. The contact surface between the inner ring hollow cylinder 2 and the inner ring surface straight section 3 is engraved with a sealing ring groove to improve airtightness. The contact surface between the inner ring surface straight section 3 and the inner ring surface contraction section 4 is engraved with a sealing ring groove to improve airtightness. The contact surface between the inner ring surface contraction section 4 and the truncated axisymmetric plug cone 5 is engraved with a sealing groove to improve airtightness.

[0066] The length of the cylindrical annulus formed by the outer mounting flange 1 and the inner hollow cylindrical surface 2 should be greater than the height of the rotating detonation wave triangle, while also taking into account the total pressure loss caused by the induced shock wave. As the detonation wave steadily and periodically sweeps through the annular cavity, the high-pressure region behind the detonation wave suppresses nearby fuel injection, naturally forming a fresh air-mixing triangle. Unlike the premixing triangle, the non-premixing triangle in the present invention exhibits a distinct stripe-like pattern of air-fuel interleaving.

[0067] Combine Figure 1 (a) and Figure 1 As shown in (b), the present invention discloses a throat-free configuration of a multifunctional rotating detonation engine exhaust system with reconfigurable morphology.

[0068] The contact surface between the outer ring mounting flange 1 and the outer ring surface contraction section 6 is engraved with a mounting groove for placing a sealing gasket; the contact surface between the outer ring surface contraction section 6 and the outer ring lip cover 7 is engraved with a mounting groove for placing a sealing gasket; the contact surface between the inner ring hollow cylinder 2 and the inner ring surface straight section 3 is engraved with a mounting groove for placing a sealing gasket; the contact surface between the inner ring surface straight section 3 and the inner ring surface contraction section 4 is engraved with a mounting groove for placing a sealing gasket; the contact surface between the inner ring surface contraction section 4 and the truncated axisymmetric plug cone 6 is engraved with a mounting groove for placing a sealing gasket.

[0069] Combine Figure 8 As shown, the present invention discloses a throat-free configuration of a multifunctional rotating detonation engine exhaust system with reconfigurable morphology.

[0070] The mainstream air first enters the cylindrical counterbore axially, then passes through circumferentially distributed radial through-holes into the contracting section of the rotating detonation combustion chamber's injection section. Then, as it passes through the throat of the rotating detonation engine's injection section, it interacts with liquid fuel injected from circumferentially distributed radial fuel injection holes, forming a combustible spray. The combustible mixture enters the expanding section of the rotating detonation combustion chamber's injection section, where it is further accelerated. Within the rotating detonation combustion chamber's annular cavity, it is excited by a high-energy electric spark, generating an asymmetric detonation wave. The detonation wave propagates along the circumference of the annular cavity. After a period of wave system interaction, it forms a unidirectional propagation mode, forming a typical rotating detonation wave triple-wave point structure within the rotating detonation engine's combustion chamber.

[0071] Combine Figure 8 As shown, because the present invention employs a discrete injection and atomization injection method, the combustible mixture triangle exhibits a distinct striped structure. The trailing shock wave induced by the detonation wave reflects and transmits through the contracting section of the rotating detonation engine nozzle. The reflected shock wave intrudes into the striped fresh mixture triangle, while the transmitted shock wave extends to the downstream nozzle expansion section, gradually weakening in intensity. The combustible / liquid mixture is converted into exhaust gas within the rotating detonation engine combustion chamber, releasing a significant amount of chemical energy. This in turn increases the total temperature of the combustion chamber, allowing the airflow to expand to a higher velocity after passing through the nozzle, thereby generating significant thrust.

[0072] Combine Figure 2 (a) Figure 2 (b) and Figure 10 As shown in (a)-(c), in the short blunt nose configuration of the multifunctional rotating detonation engine exhaust system of the present invention, the airflow will form a large recirculation area downstream of the short blunt nose cross-section.

[0073] Combine Figure 3 (a) Figure 3 (b) and Figure 10 As shown in (a)-(c), in the long blunt nose configuration of the multifunctional rotating detonation engine exhaust system of the present invention, the airflow will form a large recirculation area downstream of the long blunt nose cross-section.

[0074] Combine Figure 6 (a) Figure 6 (b) and Figure 10 As shown in (a)-(c), in the lip cover fixed half-barrel configuration of the multifunctional rotating detonation engine exhaust system of the present invention, which can be reconfigured, the airflow will form a large recirculation area downstream of the inner half-barrel cross-section.

[0075] Combine Figure 1 (a) Figure 1 (b) and Figure 11 As shown in (a)-(d), in the throat non-displacement configuration of the multifunctional rotating detonation engine exhaust system of the present invention, which can be reconfigured, the airflow will form a small recirculation area downstream of the truncated axisymmetric plug cone.

[0076] Combine Figure 4 (a) Figure 4 (b) and Figure 11 As shown in (a)-(d), in the lip cover fixed / plug cone retracted configuration of the multifunctional rotating detonation engine exhaust system with reconfigurable form in the present invention, the airflow will form a small recirculation area downstream of the truncated axisymmetric plug cone.

[0077] Combine Figure 5 (a) Figure 5 (b) and Figure 11 As shown in (a)-(d), in the plug cone fixed / lip cover retracted configuration of the multifunctional rotating detonation engine exhaust system with reconfigurable form in the present invention, the airflow will form a small recirculation area downstream of the truncated axisymmetric plug cone.

[0078] Combine Figure 7 (a) Figure 7 (b) and Figure 11 As shown in (a)-(d), in the lipless plug configuration of the multifunctional rotating detonation engine exhaust system with reconfigurable form in the present invention, the airflow will form a small recirculation area downstream of the truncated axisymmetric plug cone.

[0079] Combine Figure 1 (a) Figure 1 (b) Figure 2 (a) Figure 2 (b) Figure 3 (a) Figure 3 (b) Figure 4 (a) Figure 4 (b) Figure 5 (a) Figure 5 (b) Figure 6 (a) Figure 6 (b) Figure 7 (a) Figure 7 As shown in (b), the material of the multifunctional rotating detonation engine exhaust system with reconfigurable form in the present invention is not limited to stainless steel, but can also be various heat-resistant alloys or various heat-resistant composite materials.

[0080] Combine Figure 1 (a) Figure 1 (b) Figure 2 (a) Figure 2 (b) Figure 3 (a) Figure 3 (b) Figure 4 (a) Figure 4 (b) Figure 5 (a) Figure 5 (b) Figure 6 (a) Figure 6 (b) Figure 7 (a) Figure 7 As shown in (b), the working sequence of the multifunctional rotating detonation engine exhaust system with reconfigurable form in the present invention is as follows:

[0081] First, the air supply is turned on to form a stable cold flow field; then, the liquid fuel supply is turned on to form a stable fuel-air mixed two-phase flow field; then, the spark plug is ignited to form a stable hot rotating detonation flow field.

[0082] Combine Figure 1 (a) Figure 1 (b) Figure 2 (a) Figure 2 (b) Figure 3 (a) Figure 3 (b) Figure 4 (a) Figure 4 (b) Figure 5 (a) Figure 5 (b) Figure 6 (a) Figure 6 (b) Figure 7 (a) Figure 7 As shown in (b), the reconfigurable multifunctional rotating detonation engine exhaust system of the present invention can not only use liquid fuels but also achieve full gaseous fuel injection by varying the aperture of individual fuel injection holes. Liquid methanol is primarily used as the fuel, but is not limited to methanol. Depending on the flight mission, other fuels may include liquid kerosene, liquid ethanol, gaseous methane, gaseous ethylene, gaseous acetylene, gaseous hydrogen, and the like.

[0083] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary personnel in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A multifunctional rotating detonation engine exhaust system with reconfigurable form, characterized by: It comprises an outer ring mounting flange (1), an inner ring hollow cylindrical surface (2), an inner ring surface straight section (3), an inner ring surface contraction section (4), a truncated axisymmetric plug cone (5), an outer ring surface contraction section (6), and an outer ring lip cover (7): A plurality of radial one-way valves are evenly distributed along the circumference of the outer ring mounting flange (1) from the outside to the inside, and a spark plug connection hole is opened on one side of the radial one-way valve and on the outer ring mounting flange (1); the outer ring mounting flange (1) and the inner ring hollow cylindrical surface (2) are detachably connected; The inner ring hollow cylindrical surface (2) has a plurality of through holes evenly distributed along the circumferential direction on the cylindrical surface of a cylindrical cavity in terms of geometric characteristics. Under installation conditions, airflow enters from the inlet of the cylindrical cavity and then radially enters the upstream of the injection end of the rotating detonation engine combustion chamber from the through holes. The inner ring hollow cylindrical surface (2) is centered and positioned by the cylindrical step and the inner ring surface straight section (3), and is detachably connected. The mounting surface dimensions of the inner annular surface straight section (3) are consistent with those of the inner annular surface contraction section (4) and the truncated axisymmetric plug cone (5); the inner annular surface straight section (3), the inner annular surface contraction section (4) and the truncated axisymmetric plug cone (5) are detachably connected; The inner annular surface contraction section (4) can also be connected and fastened to the truncated axisymmetric plug cone (5) via a radial threaded countersunk hole; The outer ring surface contraction section (6) and the outer ring mounting flange (1) are detachably connected; In addition to being connected to the outer ring surface contraction section (6), the outer ring lip cover (7) can also be directly connected to the outer ring mounting flange (1); the inner wall surface of the outer ring lip cover (7) is designed by a characteristic line based on the maximum thrust theory, and the outer wall surface is provided with pressure transmitter mounting holes distributed along the axial direction and perpendicular to the inner wall surface, for connecting a pressure transmitter probe; By adding or reducing a truncated axisymmetric plug cone (5), an outer ring lip cover (7), an inner ring surface straight section (3) and an outer ring surface contraction section (6), the morphological reorganization of the exhaust system of a rotating detonation engine is achieved, thereby obtaining seven types of inner flow channel aerodynamic profiles, including short blunt head, long blunt head, lip cover fixed / plug cone retracted, plug cone fixed / lip cover retracted, throat-free dislocation, lip cover fixed half-barrel type, and lip cover-free plug type.

2. The multifunctional rotating detonation engine exhaust system with reconfigurable form according to claim 1, characterized in that: The short blunt head configuration comprises an outer ring mounting flange (1) and an inner ring hollow cylindrical surface (2); The long blunt head configuration comprises an outer ring mounting flange (1), an inner ring hollow cylindrical surface (2) and an inner ring surface straight section (3); The lip cover fixing / plug cone retraction configuration comprises an outer ring mounting flange (1), an inner ring hollow cylindrical surface (2), an inner ring surface straight section (3), a truncated axisymmetric plug cone (5), an outer ring surface retraction section (6) and an outer ring lip cover (7); The plug cone fixing / lip cover retracting configuration comprises an outer ring mounting flange (1), an inner ring hollow cylindrical surface (2), an inner ring surface straight section (3), an inner ring surface retracting section (4), a truncated axisymmetric plug cone (5) and an outer ring lip cover (7); The throat-free misalignment configuration comprises an outer ring mounting flange (1), an inner ring hollow cylindrical surface (2), an inner ring surface straight section (3), an inner ring surface contraction section (4), a truncated axisymmetric plug cone (5), an outer ring surface contraction section (6) and an outer ring lip cover (7); The lip cover fixed semi-barrel configuration comprises an outer ring mounting flange (1), an inner ring hollow cylindrical surface (2), an outer ring surface contraction section (6) and an outer ring lip cover (7); The lipless plug-type configuration comprises an outer ring mounting flange (1), an inner ring hollow cylindrical surface (2), an inner ring surface straight section (3), an inner ring surface contraction section (4), a truncated axisymmetric plug cone (5) and an outer ring surface contraction section (6).

3. The multifunctional rotating detonation engine exhaust system with reconfigurable configuration according to claim 1, characterized in that: The outer ring mounting flange (1) is provided with a dynamic pressure sensor mounting hole, which is connected to the dynamic pressure sensor through the dynamic pressure sensor mounting hole, thereby sensing the number of detonation wave heads and the detonation wave propagation frequency in the rotating detonation engine; the outer ring lip cover (7) is provided with a pressure transmitter mounting hole, which is connected to the pressure transmitter probe through the pressure transmitter mounting hole, thereby sensing the pressure distribution along the outer lip cover wall under different pressure drop ratios and equivalence ratios.

4. The multifunctional rotating detonation engine exhaust system with reconfigurable configuration according to claim 1, characterized in that: The bottom of the outer ring mounting flange (1) is provided with a cylindrical step, and the depth and radius of the cylindrical step are consistent with the size of the mounting edge of the inner ring hollow cylindrical surface (2); the outer ring mounting flange (1) and the inner ring hollow cylindrical surface (2) are connected by an axial threaded countersunk hole; the inner ring hollow cylindrical surface (2) is connected by the cylindrical step and the inner ring surface straight section (3) through radial threaded countersunk holes; the inner ring surface straight section (3) and the inner ring surface contraction section (4) and the truncated axisymmetric plug cone (5) are connected and fastened by radial threaded countersunk holes, and the interior of the truncated axisymmetric plug cone (5) is weight-reduced by multi-step step countersunk holes, and its outer wall surface is designed by a characteristic line based on the maximum thrust theory; the outer ring surface contraction section (6) and the outer ring mounting flange (1) are centered and positioned by the cylindrical step, and are connected by radial threaded countersunk holes uniformly distributed in the circumference.

5. The method for using the multifunctional rotating detonation engine exhaust system with reconfigurable form according to claim 1, characterized in that: High-pressure air first enters the inlet of the cylindrical cavity of the inner ring hollow cylindrical surface (2) and then enters the pressure stabilizing cavity (8) of the rotating detonation combustion chamber through the radial through hole. After passing through the contraction section (9) of the rotating detonation combustion chamber nozzle, the airflow is accelerated. After passing through the expansion section (10) of the rotating detonation combustion chamber nozzle, the airflow is further expanded and accelerated. The airflow interacts with the fuel injected from the radial fuel jet hole (11) of the nozzle throat to form relatively uniform atomized particles, thereby expanding the contact area between the air and the fuel droplets, which is beneficial to ignition and flame stabilization. The radial one-way valve installed outside the outer ring mounting flange (1) ensures that the fuel flows in radial injection from the outside to the inside, and the flow channel area from the radial one-way valve to the radial jet hole gradually decreases; a spark plug is installed through the spark plug connection hole, and the spark plug forms a high-voltage arc in the downstream expansion section of the injection port through a high-voltage discharge process, directly triggering the detonation phenomenon; with the help of the asymmetry of the arc generated by the spark plug, a strong and a weak detonation wave propagating in opposite directions is generated, and the detonation wave system is adaptively controlled through multiple double-wave collision processes, and finally a stable one-way detonation wave propagation mode is obtained.

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