DE102021000530A1 - Propulsion concept for starting and operating air-breathing engine systems (e.g. in ramjets) through the additional, variable introduction of an oxidizer - Google Patents

Abstract

Engine concept for starting and operating air-breathing engine systems (e.g. in ramjets) through the additional, variable introduction of an oxidizer. Air-breathing engines (e.g. ramjets) generally require an oncoming air mass flow at high speed for net thrust in order to compress using the ram effect. For example, air-breathing engines without a rotating compressor generally require additional starting aids such as a solid propellant. In particular, a special shape can be designed with additional injection of an oxidizer (e.g. for starting purposes, or at increased altitudes). However, fixed components in the engine can lead to high aerodynamic resistance at the high speeds in normal operation. The new engine concept aims to reduce resistance in regular operation and improve fluid mixing. Devices for additional injection of an oxidizer are located in front of the combustion chamber. These devices are formed from movable devices and optionally combined with fixed devices (e.g. on the intermediate body). The devices can be moved in a translatory, transverse, radial, axial, rotating or coaxial manner. Depending on the inflowing air mass flow, the additional injection of the oxidizer is variably adjusted, if necessary interrupted or run in completely. If necessary, it can be restarted or extended back into the engine. Engine concept for aerospace

Description

The invention relates to a device or concept according to the preamble of claim I.

Field of application: Aerospace

A Introduction

Compared to conventional rockets, air-breathing engine systems are to be understood as fluidically open systems. Air-breathing engine systems (e.g. ramjets, dual-mode ramjets, scramjets.) generally require a high-velocity incoming air mass flow in order to generate positive net thrust by compression in the engine. In particular, in the case of air-breathing engine systems with additional injection or injection of an oxidizer, a special form with compressed injection can be designed (e.g. for take-off purposes or at increased altitudes). In the case of pulse jet engines, self-launching aids or the supply of an oxidizer (eg O ₂ ) are known. Informative secondary sources, such as Internet articles and written statements, often report in a simplified, generally understandable or colloquial manner that separate starting aids are required for ramjets. Separate starting aids are, for example, solid propellant charges or rocket substages. However, accessible primary sources indicate at least separate development attempts with integrated self-launch aids (e.g EP 00000 100 992 7B1 , U.S. 3,514,956 , U.S. 4,644,746 , U.S. 4,930,309 , U.S. 6,510,683 B1 , U.S. 6,786,040 B2 , U.S. 2009 015 874 4A1 ). The aim is the earliest possible utilization of the inflowing air by injecting it into a powerful open engine concept with a variable proportion of combustion - which enables an effective vertical take-off with the greatest possible share of the payload from the earth. This could be used, for example, for a vertical take-off with reference to and expansion of the lift concept (Az. 10 2020 006 254.7) as a higher-level drive concept.

The mixing of secondary fluids (fuel / oxidizer) at a start is complex and energetically demanding. Pressure drops and conversion to heat are detrimental to effective combustion. Self-launch aids in ramjets can lead to high aerodynamic resistance (permanent installations in the engine flow, injection at the inlet against the entire engine duct, mixing chambers with and/without constriction of the engine, additional shafts for mixing, adjustment mechanism). This requires considerable power from the associated compressor/turbopump/compressor, or reduces the net thrust that can be achieved. In addition, the resulting resistance of permanent installations can further restrict the achievable net thrust even in the planned regular operation. In the promising patent specification US4930309A from 05.06.1990 (patented) a system with a compressor for compressing incoming atmospheric or other gas is recorded for a ramjet. Here, adjustable devices for the design of the engine flow are named. However, not for the injection itself. On the other hand, with separate starting aids, there is no multiple starting possibility without replacing the propellant charges, or lower stages, or boosters. As a result, starting with external starting aids is more expensive and chemical utilization or effective co-combustion of the inflowing air before the planned regular operation is reached is made more difficult (inflowing air mass flow, variable speed and possibly variable density at variable altitude). Because the liquid fuels are injected late. The use of additional launch aids and associated separate technology disadvantageously increases the overall launch mass. It therefore makes sense to further develop the self-launching aids of air-breathing engine systems (especially ramjets) or, if possible, to integrate them into higher-level propulsion systems.

This object is achieved by a device having the features of claim 1.

The following statements relate to the use of air-breathing engine systems (such as in particular ramjets, dual-mode ramjets, possibly scramjets with variable engine ducts that are operated with liquid fuel (e.g. H ₂ , CH ₄ ). By additional injection of an oxidizer (e.g. O ₂ ) in liquid, air-breathing propulsion systems do not require further starting devices. For this purpose, an additional injection system for an oxidizer should be used. However, the self-launching aid is to be integrated into the air-breathing engine system in the most streamlined manner possible and with little loss of injection pressure. Remaining installations in the engine duct should be avoided For the injection, a finer and more extensive atomization from outside the air mass flow with overlapping effective areas, or retractable/extendable nozzles in the air mass flow are to be used It essentially consists of a compression tank with a supply line and injectors. The reducing agent (e.g. H ₂ , CH ₄ ) is fed into the supplied air-breathing engine system in the additional injection system or in the actual injection system. A mixture is formed together with the inflowing air mass flow and burned in the combustion chamber. With the achievement of self-compression in the air-breathing drive factory system required inflow speed, the additional injection system for the oxidizer can be switched off or, if necessary, retracted/extended. Multi-stage combustion can be used to achieve higher compression with low or changing inflow, or to further increase the mass flow and net thrust in the air-breathing engine system. This corresponds to the principle of the turbocharger in a private vehicle, in which the exhaust gas pressure increases the injection pressure. The goal is more effective and complete combustion in the main combustion chamber. Pre-combustion can be discharged into the combustion chamber either subsonic or supersonic.

A possible adjusting device for an additional injection of an oxidizer in the air-breathing engine offers the possibility of achieving a higher injection pressure with less resistance of the pump system and reducing the flow resistance of the additional injection itself when normal operation is reached. The total take-off mass to be accelerated is nevertheless reduced compared to conventional rocket engines, since the additional injection only requires part of the oxidizer to be carried along. This improves the economy or the overall efficiency and allows more flexible application scenarios. Future tasks such as space mining and space settlement are to be realized. With a related vertical launch from the earth's surface, it would be possible to escape to an orbit, or from the earth's surface and beyond, by the shortest possible route. Thus, the characteristic time-velocity curve for the scenario of a vertical take-off of conventional rocket engine systems can be further adjusted and extended with the area of application of an air-breathing engine system. An optimization of the use of the air-breathing engine system is possible through a designed guidance system and a control system. The operational reliability of the air-breathing engine systems is further increased via the control system and control system by preventing stalls or reducing scavenging or spill mass flow. A possible use for fast horizontal flights is also improved. An actual assignment of this patent specification to the lifting concept (Az. 10 2020 006 254.7) is reserved for further processing of the final patent submission and external examination. Conventional rocket engine systems should therefore be partially or completely dispensed with (especially for the start). This would reduce the need for fuel to be carried (less oxidizer, possibly also less reducing agent due to reduced co-acceleration of oxidizer). It is also possible to continue using the additional injection to increase performance, or to stabilize it, or to restart it (e.g. when the atmospheric density is reduced). The injection system for the oxidizer (eg O ₂ ) can continue to be operated in space in order to increase the area of application. The possible application scenarios are very promising. Alternatively, exclusively air-breathing engine systems can be combined with fed-air-breathing engine systems.

character list

• 1: Übersicht des Triebwerkskonzeptes
• 2a: Ramjet: variables Einspritzsystem Lanzen - ausfahrbar
• 2b: Ramjet: variables Einspritzsystem Lanzen - drehbar
• 2c: Ramjet: variables Einspritzsystem Lanzen - quer einfahrbar
• 3a Ramjet: Ausführungsvariante, aufgefächert, ohne einfahrbarer Einspritzung
• 3b Ramjet: Ausführungsvariante, aufgefächert, mit einfahrbarer Einspritzung
• 4a Ramjet: vereinfachte Ausführungsvariante
• 4b Ramjet: Ausführungsvariante mit innerer Zusatzeinspritzung
• 5a Ramjet: Ausführungsvariante mit Verbrennung (Druckaufladung)
• 5b Ramjet: Ausführungsvariante mit Verbrennung, bewegliche Einspritzung
• 6: Ramjet mit angeschlossener Aerospike-Düse

Embodiment variants of the invention are shown in the drawings and are described in more detail below.

• 1 : Overview of the engine concept
• 2a : Ramjet: variable injection system lances - extendable
• 2 B : Ramjet: variable injection system lances - rotatable
• 2c : Ramjet: variable injection system Lances - transversely retractable
• 3a Ramjet: Variant, fanned out, without retractable injection
• 3b Ramjet: Variant, fanned out, with retractable injection
• 4a Ramjet: simplified design variant
• 4b Ramjet: Variant with additional internal injection
• 5a Ramjet: variant with combustion (pressure charging)
• 5b Ramjet: Variant with combustion, flexible injection
• 6 : Ramjet with attached aerospike nozzle

The invention consists of a liquid-based engine concept with an air-breathing engine system (1) or additional injection of an oxidizer (12) to improve the starting ability and the area of use.

The design variants only represent examples of rotationally symmetrical concepts. Further variants are covered by the description or claims.

Figure 1 Overview of the engine concept

The air-breathing engine system (1) consists of inlet (2), mixing area (3), combustion chamber (4) nozzle (5). A central body (22) is arranged in the inlet (2) and the mixing area (3). In front of the inlet (2) there is a guidance system for support (6) arranged with adjustment system (7). The air-breathing engine system (1) consists of 2 injection systems. For regular operation with sufficient inflow of air mass flow (17), there is an injection system for the fuel (8) consisting of a tank (9) and lines, a heat exchanger, including a compressor (10). The fuel (8) is brought into the mixing area (3) with the inflowing air mass flow (17) via the injection (11). Alternatively, the fuel can flow into the feed line (19) for additional injection (16 and 26) via a valve (18). Ignition devices (20) are arranged in the combustion chamber (4).

A separate injection system is available for self-start and outside of regular operation. The required oxidizer (12) is connected to an additional injection (16) in a tank (13) and a line system including a compressor (14). In order to relieve the compressor (14), the injection (16) for the start is arranged in front of the combustion chamber (4). The fuel (8) is connected to the injection (16) for the start via an intermediate valve (18) and a separate line system including a heat exchanger/preheater (19). Nozzles with a high degree of atomization are used in order to achieve a mixture (21) that is as complete and uniform as possible (aligned nozzles with a high degree of atomization (e.g. hollow cone nozzles, pintle nozzles, etc.). The mixture (21) is ignited in the combustion chamber (20). Des Furthermore, a heat exchanger (15) is thermally connected to the combustion chamber (4) in the line system (9) in order to heat the oxidizer (12) before it is injected. If necessary, an additional inflow ( 67) to the air mass flow (17) can be achieved when starting.

The additional injection (16 and 26) is adjusted via a controller (27) or, if necessary, reduced to the pressure of the combustion chamber (4) in order to prevent backflow or flow around the additional injection (16 and 26). This is done by measuring the pressure drop before and after additional injection (16 and 26) and in the combustion chamber (4). In addition, speedometers are arranged in the air mass flow (17) via the control (27) in order to adapt the injection rate of the oxidizer (12) to the speed or density and mass of the air mass flow (17).

When the required inflow speed is reached, the inflowing air (17) in the air-breathing engine (1) alone is sufficient for complete combustion of the reducing agent (H ₂ , CH ₄ ) or fuel (8). The additional injection (16 and 26) of the oxidizer (8) is terminated. The intermediate valve (18) is closed and the fuel (8) is supplied to the mixing area (3) with the inflowing air (17) via the injection (11) provided for control operation. The ignition (20) then burns in the combustion chamber (4) and expands in the nozzle (5).

If necessary, at another point in time when higher layers of air with lower air density are reached, the supply of the air mass flow (17) required for the required combustion may be undershot (e.g. in a vertical start scenario from the earth's surface). The inflow or the air mass flow (17) can be varied in a targeted manner via a control system (6) and a control system (7). In this way, the most comprehensive possible operation of the air-breathing engine system (1) is to be made possible by adjusting the inflow area of the control system (6) via the adjusting device (7). After the operating limits of the control system (6) have been exceeded, the additional injection (16 and 26) of the oxidizer (12) can be re-ignited. If necessary, the fuel (8) is injected via the control injection (11).

Figure 2a Ramjet: variable injection system lances - extendable

When starting, the additional injection of an oxidizer (12) is required due to the lack of air mass flow (17). In this embodiment variant, the injection (16 and 26) takes place exclusively along the air mass flow (17). The oxidizer is injected with a reducing agent in a mixture (21) via the fixed injection (16) in the head of the combustion chamber (4). In addition, movable lances with injection devices (26) are extended in the area of the engine duct. The lances with the movable injection (26) are arranged concentrically around the axis of the air-breathing engine (1). In the variant, the lances are each offset by 30° to one another. The lances are inserted at an angle into the engine flow in order to cause the lowest possible flow resistance. The lances are designed in such a way that they oppose the inflow or the combustion chamber pressure with a higher area moment of inertia. This means that the cross section of the lances (26) is longer than it is wide, and the length is aligned with the longitudinal axis of the engine. The lances also have a streamlined, eg drop-shaped, cross-section. The lances (26) can be mounted on the outside of the engine or on the inside of the intermediate body (22). In the embodiment variant shown, the lances are mounted on the outside. The lances are moved with hydraulics (28), alternatively cushions or electric motors/actuators with the appropriate power are also possible. About the injection at the same time becomes fuel in one Mixture (21) injected. Nozzles are arranged at several points on the lances (26). Multi-way nozzles are preferably used for this. The atomized mixture (21) is ignited in the combustion chamber (4).

The additional injection of the oxidizer in the mixture (21) is adapted to the air mass flow (17) or, if necessary, reduced. Due to the increasing speed, an increasing air mass flow (17) flows into the combustion chamber (4): the adjusting device with the movable lances (26) is pulled back or retracted. When the engine is shut down, there are no essential built-in components of the self-starting aid or the additional injection (16 and 26) in the engine duct. The additional injection is deactivated in the preferred embodiment. However, the additional injection can either continue to be operated to increase performance or be put into operation again. Otherwise, the fuel (8) is injected via the control injection system (11) and mixed with the air mass flow (17) in the mixing chamber (4). If necessary, the fuel (8) is injected via the control injection (11).

Figure 2b Ramjet: variable injection system lances - rotatable

Compared to the aforementioned variant ( 2a) the lances (26) are rotatably mounted with the possibility of tilting and are pivoted into the air mass flow (17) or pivoted back. The movement is hydraulically guided (28). The adjustable injection (26) can be attached or guided either outside or inside the intermediate body (22). In this embodiment variant, the injection (16 and 26) takes place exclusively along the air mass flow (17).

The additional injection of the oxidizer in the mixture (21) is adapted to the air mass flow (17) or, if necessary, reduced. According to the variant 2a the additional injection (16, 26) is then optionally deactivated, operated in parallel, or used again. When the additional injection (16, 26) is switched off, no significant flow resistances remain in the engine duct. If necessary, the fuel (8) is injected via the control injection (11).

Figure 2c Ramjet: variable injection system lances - retractable transversely

Compared to the aforementioned design variants ( 2a and 2 B) the lances (26) can be moved transversely or transversally into the engine. In the cross section of the air mass flow (17) is with the smallest possible. approach surface engaged. The movement is hydraulically guided (28). The adjustable injection (26) can be attached or guided either outside or inside on the intermediate body (22) in the engine. In this variant, the injection (16, 26) takes place exclusively along the air mass flow (17).

The additional injection of the oxidizer (12) is adapted to the air mass flow (17) or, if necessary, reduced. According to the variant 2a the additional injection (16, 26) is then optionally deactivated, operated in parallel, or used again. When the additional injection (16, 26) is switched off, no significant flow resistances remain in the engine duct. If necessary, the fuel (8) is injected via the control injection (11).

FIG. 3a Ramjet: Design variant, fanned out, without retractable injection

Compared to the design variants in 2a, b and c the injection (16) of the mixture (21) does not take place exclusively longitudinally in the flow direction of the air mass flow (17), but in a radial or planar and widened manner (eg via hollow cone or pintle nozzles). This contributes to a finer distribution and better combustion in the starting phase. In the variant embodiment, the additional injection nozzles (16) are distributed over the entire head of the combustion chamber (4). In this embodiment variant there is no retractable injection, but only a fixed injection (16). The shape of the injection is thus simplified. For the injection (16), nozzles are arranged on the outside of the air mass flow and on the inside of the intermediate body (22). The injection (16) arranged on several sides with a crossing area of action or overlap replaces the movable injection of other design variants (e.g 2a) .

The additional injection of the oxidizer is adapted to the air mass flow (17) or, if necessary, reduced. With increasing speed, the mass flow of the incoming air (17) increases and the additional injection (16) is interrupted or ended. If necessary, the additional injection (16) can be started again. If necessary, the fuel (8) is injected via the control injection (11).

Figure 3b Ramjet: Variant, fanned out, with retractable injection

Compared to the variant 3a the additional injection does not take place exclusively from permanently installed nozzles (16), but is carried out by retractable/extendable nozzles (26) in the air mass stream (17) supported. In addition, the additional injection (16, 26) does not take place exclusively in a longitudinal direction, but in a radial or planar manner (eg via hollow cone or pintle/needle nozzles). Thus, in this embodiment variant, the additional injection (16, 26) is distributed over the entire head of the combustion chamber (4).

The additional injection (16, 26) of the oxidizer (12) is adapted to the air mass flow (17) or, if necessary, reduced. With increasing speed of the air-breathing engine system (1), the mass flow of the incoming air (17) increases and the additional injection (16, 26) is interrupted or ended. If necessary, the additional injection (16, 26) can be started again if required. The movable injection (26) is possibly retracted or extended again. If necessary, the fuel (8) is injected via the control injection (11).

FIG. 4a Ramjet: simplified variant

In order to minimize flow resistance in the air-breathing engine (1) and to streamline the engine design, there are no nozzles and installations on the outside of the air-breathing engine (1). This embodiment variant is also characterized in that retractable/extendable nozzles are dispensed with. These two properties create a greatly simplified variant of the engine concept. The joint additional injection (16) of the oxidizer (12) with the reducing agent produces the mixture (21) and takes place from the intermediate body (22) of the air-breathing engine (1). The nozzles (e.g. hollow cone nozzles or pintle nozzles) fan out the mixture (21) in the combustion chamber (4), in which ignition (22) takes place immediately.

The proportion of the oxidizer in the mixture (21) is adapted to the air mass flow (17) or, if necessary, reduced. The air mass flow (17) mixes with the additional injection (16). When the required inflow speed and density of the air mass flow (17) is reached, the additional injection (16) is ended. The additional injection (16) is only ignited again when the flow falls below the required level again. If necessary, the fuel (8) is injected via the control injection (11).

Figure 4b Ramjet: Variant with internal additional injection

Opposite to 4a retractable/extendable lances or devices for additional injection (26) in the air mass flow are available in this variant. In order to minimize flow resistance in the air-breathing engine (1) and to streamline the engine design, there are no nozzles and installations on the outside of the air-breathing engine (1). Therefore, the slidable additional injection (26) is movably attached to the inside of the intermediate body (22). The nozzles (eg hollow cone nozzles or pintle nozzles) of the additional injection (16 and 26) fan out the mixture (21) in the combustion chamber (4), in which ignition (22) takes place immediately.

The additional injection (16, 26) of the oxidizer is adapted to the air mass flow (17) or, if necessary, reduced. The incoming air (17) flows into the additional injection (16, 26). When the required inflow speed and density of the air mass flow (17) is reached, the additional injection (16, 26) is ended. The additional injection (16, 26) is only ignited again when the flow falls below the required level again. The movable injection (26) is possibly retracted or extended again. If necessary, the fuel (8) is injected via the control injection (11).

Figure 5a Ramjet: Variant with combustion (pressure charging)

This variant with staged combustion dispenses with retractable/extendable injection. In principle, further stages are conceivable according to this principle, but this is omitted in the illustration in order to avoid excessive flow resistance in normal operation and to provide a solution that is as simple and realizable as possible.

The design variant with a pre-combustion chamber (50) generates an additional boost or further pressure charging in the air-breathing engine system (1) in front of the main combustion chamber (4). This principle corresponds to the turbocharger of a private car, which increases the charging pressure of the combustion process via the exhaust gas flow. The aim is more effective and more complete combustion in the main combustion chamber (4) or its shielding against an insufficient, fluctuating or unfavorable inflow of the air mass flow (17). Supersonic combustion can also be initiated in the combustion chamber (4) by the pre-combustion (50), including compressing pressure surges. Thus, a multimode operation of the air-breathing engine system (1) can be facilitated and the air-breathing engine system (1) can continue to be operated with increasing speed (for example in the case of a vertical take-off from earth). The advantage of this configuration compared to other patents is that the entire inflowing air mass flow (17) is guided into the precombustion (50) with the greatest possible pressure. There are other devs approaches with internal systems for self-launch (in a larger engine duct).

When starting operation without sufficient inflow of the air mass flow (17), the mixture (52, or 21) for the combustion is produced by additional injection (16) of the oxidizer with the reducing agent (8). The nozzles (e.g. hollow cone, needle or pintle nozzles) fan out the mixture (52) in the pre-combustion chambers (50), in which ignition (53) takes place immediately. The combustion creates a flow pressure on the main combustion chamber (4). Depending on the air mass flow (17), the mixture (21) of oxidizer and fuel is optionally injected via the additional injection (16), or only fuel (8) is injected via the injection (11) provided for control operation. Ignition and main combustion occurs more effectively under increased pressure in the combustion chamber (4).

The additional injection (16, 56) of the oxidizer in the mixture is adapted to the air mass flow (17) or, if necessary, reduced. The incoming air (17) flows into the additional injection (16, 56). When the required inflow speed and density of the air mass flow (17) is reached, the additional injection (16, 56) is ended. The additional injection (16, 56) is only ignited again when the flow falls below the required level again. If necessary, the fuel (8) is injected via the control injection (11 and 51).

Figure 5b Ramjet: Variant with combustion, flexible injection

This embodiment variant corresponds to the embodiment variant 5a with the exception of the additional retractable/extendable injector (26, 57) in the precombustion chamber (50) and the retractable/extendable injector (26) of the main combustion chamber (4).

When starting operation without sufficient inflow of the air mass flow (17), the mixture (52) for the combustion is produced by additional injection (16) of the oxidizer (12) with the reducing agent/fuel (8). Movable nozzles (57) are swiveled out on rotatable lances in the air mass flow (17). The mixture (52) in the pre-combustion chambers (50) is ignited. The movable additional injection (57) remains extended until there is sufficient supply by the air mass flow (17). Similarly, in front of the main combustion chamber (4), the movable additional injection (26) is pivoted into the pre-combusted air mass flow (17) until the inflowing residual oxygen content of the air mass flow (17) allows the additional injection (16 and 26) to be deactivated. This principle ensures the greatest possible burnout of the air mass flow (17) and the supplied fuel (8) is completely burned with the greatest possible compression. In regular operation, combustion occurs exclusively via the main injection (11, 51). Each for pre-combustion chambers (50) and combustion chamber (4).

The additional injection (16, 26, 56, 57) is only ignited again when the flow falls below the required level again. If necessary, the fuel (8) is injected via the control injection (11).

Figure 6: Ramjet with attached aerospike nozzle

For a vertical take-off scenario with changing inflow speeds and external pressures, the use of an air-breathing engine (1) is controversial among experts and has not yet been technologically solved. In the following, for this embodiment variant, a modification is described by combining it with a control system (6) for an additional air mass flow (17), an adjustment system (7) for controlling an additional air mass flow (67), an additional injection of an oxidizer in a mixture (21) and the thrust conventional rocket engines (60) selected. In a broader sense, this corresponds to the "lifting concept" (Az. 10 2020 006 254.7) of the applicant of the same name.

The oxidizer (eg O ₂ ) for supplying the conventional rocket engines (60) can be taken from the tank of the conventional rocket engines (60), which is required in any case.

A typical speed-time profile, eg of a "Falcon Heavy" rocket, provides a burning time of approx. 150 s with a final speed of approx. 6,800 km/h and an altitude of approx. 62 km for the relevant 1st stage of the side buster. The general range of use of ramjets is specified from Mach 1.5 to approx. Mach 5, ie roughly approx. 1,800 - 6,000 km/h. The minimum inflow speed is only reached after approx. 90 s (without additional measures) and is exceeded after approx. 150 s with separation of the 1st stage (without adjustment). Approximately 60% of the 1st stage burn time is below the typical range of ramjets. By additionally injecting an oxidizer (8) and a control system (6), the air-breathing engine system (1) can already be used during most of the combustion period of the 1st stage before Mach 1.5 is reached. Due to the additional net thrust of the air-breathing engines (1), the usual minimum face velocity of ramjets can be reached ahead of schedule (Mach 1.5). When the minimum inflow speed is reached, the conventional rocket engines (60) can continue to be operated or alternatively they can be operated rer air-breathing engines possible, which can be operated without additional measures. Due to the high variability of the speed, a combination with aerospikes (61) is advantageous in order to limit energy losses due to over-/under-expansion. The proposed combination is ideal for continued operation at higher altitudes.

Before the starting phase (phase I), the guide device (6) is extended for the greatest possible flow of the air mass flow (17) and an additional air mass flow (67). The movable additional injection (26) in the ramjet is extended or in operation.

In the starting phase (phase II), the air-breathing engine system (1) is started using the self-starting aid consisting of additional injection (16 and 26). Oxidizer and reducing agent are injected in a mixture (21). In addition, the conventional rocket engines (60) contribute to the acceleration to the minimum flow velocity required. In phase II, the portion of the proportionately combustible air mass flow (17) increases. The adjustment device (7) adapts the guide device (6) to the speed, reduces and minimizes the flow around the air-breathing engine system (1), i.e. the inflow area is reduced.

In the transitional phase (phase III), the inflow speed has already been reached prematurely by the guide device (6). The additional injection (16 and 26) is deactivated and the movable additional injection (26) is retracted. The injection takes place exclusively via the main injection (11) and exclusively of reducing agent (8), such as H ₂ or CH ₄ . This means that no further injection of an additional oxidizer (usually up to approx. 75% of the total launch mass of the rocket) is required.

The regular operating phase (phase IV) is defined when the minimum inflow velocity is reached. The guide device (6) and adjusting device (7) optimizes the operation of the air-breathing engine systems (1).

In phase 5, the maximum speed is exceeded and the decreasing air density requires continued operation and swiveling open of the guide device (6), or renewed use of the additional injection (16 and 26).

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 000001009927 B1 [0003]
• US 3514956 [0003]
• US4644746 [0003]
• US4930309 [0003]
• US 6510683 B1 [0003]
• US 6786040 B2 [0003]
• US20090158744A1 [0003]
• US4930309A [0004]

Claims (8)

Device for the additional injection of an oxidizer in air-breathing engine systems (e.g. ramjets or dual-mode ramjets, scramjets). Characterized in that in an air-breathing engine system (1) by an additional injection (16, 26, 56, 57) of an oxidizer (12) a) by means of permanently installed nozzles (e.g. hollow cone nozzles, pintle nozzles), or openings with multi-path feed and each other overlapping spray areas in front of the combustion chamber (4), or by means of permanently installed nozzles and movably guided nozzles (e.g. hollow cone nozzles, pintle nozzles), or variably installed openings for the air mass flow (17) either in a translatory, transverse, radial, axial, rotating or coaxial manner , retractable and extendable b) the additional injection (16, 26, 56, 57) of the oxidizer (12) and/or the reducing agent (8) is variably adjusted, that is to say maximized, minimized, interrupted, re-ignited or pulsed can be. device after claim 1 . Characterized in that a measuring and control device (27) measures the pressure and the speed of the engine or air mass flow (17) and/or the combustion chamber pressure and then the control of the injection pressure and the injection rate, actually active nozzles, as well as a variable proportion of the Reducing agent / or fuel (8) and possibly oxidizer (12) continuously adjusts. device after claim 1 or 2 . Characterized in that the air mass flow (17) or the additional injection of the reducing agent (16, 26, 56, 57) in several combustion chambers (4, 50) is burned proportionately or in stages, or is compressed or accelerated. device after claim 1 , 2 and 3. Characterized in that is burned in one or more combustion chambers in the supersonic range. device after claim 1 or 2 . Characterized in that the air mass flow (17) is initiated, accelerated or maintained by combination with a conventional rocket engine. device after claim 1 or 2 . Characterized in that on air-breathing engine systems (1), the additional variable injection (16, 26) of an oxidizer is operated with an additional inflowing atmosphere or air, which is compressed and accelerated via a control system (6) regulated by a control system (7). becomes. device after claim 1 or 2 . Characterized in that air-breathing engine systems (1) with additional variable injection (16, 26) of an oxidizer (12) and/or reducing agent (8) are operated with or at times with air-breathing engine systems without additional variable injection of an oxidizer (12). device after claim 1 or 2 . Characterized in that an aerospike or aerospike nozzle (61) is arranged on air-breathing engine systems (1) with additional variable injection (16, 26) of an oxidizer.

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