JP2023548715A - Integral body scramjet with fixed geometry and geometry transition for hypersonic operation over large Mach number range - Google Patents

Abstract

An integrated airframe scramjet engine is disclosed. A scramjet engine within the scope of the present disclosure may be configured to smoothly integrate with the airframe of a hypersonic aircraft or flying vehicle. A scramjet engine has an inlet capture shape configured to capture airflow, a combustor configured for combustion of fuel and air, and a combustor configured to capture the fuel and air to provide hypersonic thrust. and a nozzle outlet configuration configured for expansion of air. In some embodiments, the scramjet engine has a fixed shape and a transitional cross-sectional shape throughout its length. A scramjet engine is configured to be a component of a projectile system.
[Selection diagram] Figure 1

Description

This disclosure relates to hypersonic air-breathing propulsion systems. More particularly, the present disclosure relates to supersonic combustion ramjet (scramjet) engines. In some embodiments, the present disclosure relates to an integrated airframe scramjet engine.

In order that the features and advantages of the invention may be understood in more detail, a brief description of the invention may be obtained by reference to the figures of the accompanying drawings. It should be noted, however, that the drawings depict only embodiments of the invention and therefore should not be considered as limiting the scope of the invention, since the invention also This is because some other embodiments that are effective may be admitted to.
1 is a schematic cross-sectional view of a portion of the fuselage of a hypersonic vehicle including one embodiment of an integrated body scramjet engine; FIG. 2 is an isometric view of an embodiment of the scramjet engine of FIG. 1; FIG. FIG. 2 is a bottom view of the scramjet engine of FIG. 1; 2 is an isometric view of an embodiment of the inlet of the scramjet engine of FIG. 1; FIG. FIG. 5 is a front view of the inlet embodiment of FIG. 4; 2 is a side view of the scramjet engine of FIG. 1 showing the location of the fuel injection station; FIG.

A scramjet is an air-breathing engine for hypersonic flight. It can be an alternative propulsion system to rockets for space launches and long-distance, high-speed flights. Hypersonic speed is defined as traveling at speeds greater than Mach 5, where Mach 1 is the speed of sound in air at sea level. In certain embodiments, a scramjet engine can include an inlet, a combustor, and a nozzle. The inlet may be configured to capture the airflow and compress it to conditions suitable for combustion of the fuel with oxygen in the air. Air entering the combustor from the inlet can be combusted with fuel while maintaining supersonic speeds. The air and combustion products then enter a nozzle where they are expanded and accelerated to provide hypersonic engine thrust before exiting the scramjet engine. A scramjet engine is intended to generate forward thrust to power a hypersonic flying aircraft or vehicle while flying through the atmosphere at hypersonic speeds. If a scramjet engine is capable of producing forward thrust at a particular flight Mach number, then the scramjet engine is considered to operate at that flight Mach number.

In some embodiments, a scramjet engine can be smoothly integrated into a hypersonic airplane or vehicle designed to move at hypersonic speeds. Additionally, a scramjet engine can include a cross-sectional shape transition along its length so that it can meet the conflicting requirements of airframe integration and robust combustion. In addition, scramjet engines can be configured to generate thrust in the direction of motion over a range of large Mach numbers in a fixed geometry. In other words, a scramjet engine is capable of accelerating a hypersonic airplane or vehicle over a large hypersonic Mach number range without changing its geometry. The ability to generate thrust in the direction of motion over a large hypersonic Mach number range means that scramjet engines can be configured to accelerate hypersonic vehicles or vehicles and as part of a space launch system. means it can be used.

Embodiments can be understood by reference to the drawings, in which like parts are designated by like numerals throughout. Those skilled in the art with the benefit of this disclosure will readily appreciate that the components of the embodiments generally described herein and illustrated in the figures can be configured and designed in a wide variety of different configurations. . Accordingly, the following more detailed description of the various embodiments as depicted in the drawings is not intended to limit the scope of the disclosure, but is merely representative of the various embodiments. Various aspects of the embodiments are presented in the drawings, which are not necessarily drawn to scale unless otherwise indicated.

It will be appreciated that various configurations are sometimes grouped together in a single embodiment, figure or description thereof for the purpose of simplifying the disclosure. Many of these features can be used alone and/or in combination with each other.

The expressions "coupled to" and "in communication with" refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluidic, and thermal interactions. Including action. The two components may be coupled to each other or in communication with each other even if they are not in direct contact with each other. For example, two components may be coupled or in communication with each other via an intermediate component.

The directional terms "fore" and "aft" are given their usual meaning in the art. That is, "forward" refers to the front or leading portion of a hypersonic airplane or vehicle, and "aft" refers to the rear or tail portion of the hypersonic airplane or vehicle.

1-6 illustrate different views of embodiments of integrated airframe scramjet engines and associated components. In particular figures, each engine may be coupled to or shown with additional components not included in all figures. Additionally, in some figures, only selected components are shown to provide details of component relationships. Some components may be shown in multiple figures but are not described in connection with every figure. Disclosures provided in connection with any figure are applicable in relation to disclosures provided in connection with any other figure or embodiment.

FIG. 1 shows a schematic cross-sectional view of a portion of a hypersonic airplane comprising an airframe 190 that includes an integrated scramjet engine 100 according to the present disclosure. The aircraft 190 includes a front body 191, an intermediate portion of the body 193, and a rear body 192. The disclosed scramjet engine 100 has a front fuselage body 191 attached to the aircraft 190 so as to compress air captured by the scramjet engine 100, and a rear fuselage body 192 that compresses the air captured by the scramjet engine 100. After exiting the scramjet engine 100, the exhaust gas from the scramjet engine 100 continues to expand.

The disclosed scramjet engine 100 can be smoothly integrated into an air vehicle 190. This ensures that the scramjet engine 100 is configured such that air flowing along the fuselage front body 191 passes smoothly through and around the scramjet engine 100 with minimal disruption or turbulence, and/or It is meant to be attached to the aircraft 190 such that the exhaust from the scramjet engine 100 flows smoothly over and above the fuselage aft body 192.

FIG. 2 shows the capture shape 134, shape transition 146, and exit shape 164 of the disclosed scramjet engine 100. As shown in FIG. 2, the disclosed scramjet engine 100 has a capture shape 134 that can be smoothly integrated with the front body 191 of a hypersonic airplane or vehicle 190, and a retracted and It includes an expanding shape transition 146 and an exit shape 164 that can smoothly integrate with the aft body 192 of a hypersonic airplane or vehicle 190. Shape transition 146 is a configuration of the disclosed scramjet engine 100 that has a geometry in which both acquisition shape 134 and exit shape 164 smoothly integrate with the range of various hypersonic aircraft or air vehicles 190. be independently specified to meet scientific requirements. Another feature of the shape transition 146 is that it allows the internal shape of the disclosed scramjet engine 100 to be configured to produce robust combustion and thrust in the direction of motion over a large Mach range. .

The operating Mach range of a scramjet engine is the range of Mach numbers over which the scramjet engine produces thrust in the direction of motion. The minimum Mach number at which the disclosed scramjet engine 100 operates is Mach 5. A large operating Mach range for a scramjet is considered to be an increase in Mach number 3. The disclosed scramjet engine 100 has a minimum operating range of Mach 5 to Mach 8, and thus can be considered to have a large operating Mach range. In some embodiments, the disclosed scramjet engine 100 can have an operating Mach range of Mach 5 to Mach 12.

The disclosed scramjet engine 100 shown in FIG. 2 can smoothly integrate with the airframe 190 at the acquisition shape 134 and the exit shape 162 to produce net thrust. Otherwise, the thrust generated by the scramjet engine 100 may be counteracted by external drag generated by the aerodynamic interaction between the hypersonic airplane or vehicle 190 and the scramjet engine 100. In other embodiments, variations in shape transition 146 allow scramjet engine 100 to be installed on hypersonic aircraft or air vehicles 190 of various shapes.

The capture geometry 134 of the disclosed scramjet 100 captures a high percentage of the airflow available at higher Mach numbers in the operating range of the disclosed scramjet engine 100, but at smaller Mach numbers within the operating Mach range of the disclosed scramjet engine 100. Constructed in such a way that air spills out.

The disclosed scramjet engine 100 may be used to power a hypersonic airplane or vehicle 190 during hypersonic flight. For example, the scramjet engine 100 can power a hypersonic airplane or vehicle 190 at hypersonic speeds within its operating Mach range without a change in geometry during hypersonic flight.

FIG. 3 illustrates an embodiment of a scramjet engine 100 according to the present disclosure. As illustrated, the disclosed scramjet engine 100 may include three general components. These components include (1) an inlet 120 configured to capture a supersonic airflow and compress and heat the airflow to conditions suitable for fuel combustion through the action of shock waves and airflow expansion; (2) a combustor 140 in which fuel and air are combusted to add energy to the airflow passing through the scramjet engine 100; and (3) combustion products (e.g., water and carbon dioxide) and any unburned air. or a nozzle 160 in which fuel expands to generate thrust. Inlet 120 includes a surface that extends from capture feature 134 to throat 129 of disclosed scramjet engine 100. The combustor includes a surface extending from throat 129 to nozzle inlet 128. Nozzle 160 includes a surface extending from nozzle inlet 128 to outlet feature 164 of the disclosed scramjet engine 100.

FIG. 4 shows an embodiment of an inlet 120 of a scramjet engine 100 according to the present disclosure. The capture feature 134 of the inlet 120 may be configured to smoothly integrate with the front body 191 of the hypersonic airplane or vehicle 190. In other embodiments, the acquisition shape 134 of the inlet 120 is configured to facilitate smooth integration with any suitable hypersonic flying aircraft or vehicle, including a winged hypersonic aircraft or a hypersonic missile. can be adjusted to For example, the front body 191 can include a convex shape, a concave shape, a planar shape, etc.

The capture shape 134 of the inlet 120 is a closed shape that includes a body side leading edge 130 , a pair of side leading edges 122 , and a pair of cowl leading edges 125 . The body side leading edge 130 is attached directly to the front body 191 along its entire length. A pair of side leading edges 122 are attached to each end of the body side leading edge 130 and project rearwardly and away from the front body 191 at an angle of less than 90 degrees relative to the front body 191 . The pair of cowl front edges 125 are attached to the rear ends of the side front edges 122, are disposed between the pair of side front edges 122, and are joined at a cowling notch 126. Cowling notch 126 may be configured to allow excess airflow to exit inlet 120, as described further below.

Inlet 120 may be a mixed contraction inlet. Capture shape 134 of inlet 120 is configured to provide external and internal air compression or deflation that allows scramjet engine 100 to self-start over its operating Mach range. Self-starting means that supersonic airflow is established through the scramjet engine 100 at the applicable hypersonic flight Mach number. If supersonic airflow is not established, scramjet engine 100 cannot generate thrust in the direction of motion in hypersonic flight conditions. Inlet 120 is configured to provide the necessary amount of airflow compression to enable as robust a combustion of fuel and air in combustor 140 as possible.

The throat 129 of the disclosed scramjet 100 may be located aft of the cowling notch 126. Throat 129 can have a smaller cross-sectional area than capture feature 134. Throat 129 may communicate with inlet 120 and combustor 140 such that air collected by inlet 120 flows from inlet 120 through throat 129 to combustor 140 . Throat 129 can have a rounded shape. For example, the rounded shape may be oval, circular, oblong, or any other suitable shape that does not include sharp corners.

FIG. 5 illustrates a view of an inlet 120 according to the present disclosure looking downstream. FIG. 5 shows inlet 120 with a smooth shape transition from capture shape 134 to rounded throat 129. A smooth shape transition is shown as a given contour line 131 that is substantially evenly spaced from the capture shape 134 to the rounded throat 129. The smooth shape transition of the inlet 120 can result in lower internal drag and therefore greater overall thrust opportunities from the disclosed scramjet engine 100.

As shown in FIG. 3, round throat 129 connects directly to the inlet of combustor 140. The round throat 129 has the same shape and cross-sectional area as the combustor inlet. The cross-sectional area of combustor 140 may increase along its length from a combustor inlet to a combustor outlet. Combustor 140 has a rounded cross section with no sharp corners along its entire length. A combustor 140 with a rounded cross-section has a lower structural weight required to maintain a particular pressure, and a smaller air flow through which is required to enclose a particular flow area. In terms of surface area, it is superior to combustors 140 with cross-sections that include corners (eg, square, rectangular, etc.). The hydrodynamic problems associated with hypersonic corner flows also do not exist with the rounded cross-section of combustor 140.

The area and cross-sectional shape of the combustor 140 are varied along its length to allow efficient combustion of fuel without adjusting its physical shape over the range of operating Mach numbers of the scramjet engine 100. Change. This is accomplished by including multiple fuel injectors in the engine and utilizing various combinations of fuel injectors and fuel metering levels from each fuel injector.

As shown in FIG. 3, combustor 140 includes a single backward step 141 around its rounded cross-sectional area.

FIG. 6 shows a side view of a scramjet engine 100 in accordance with the present disclosure showing possible locations of four fuel injection stations 142, 143, 144, 145 along the length of the scramjet engine 100. As shown in FIG. 6, fuel injection stations 142, 143, 144, and 145 are located on the main body side 133 of the inlet 120 (station 1 142), upstream of the backward step 141 (station 2 143), and next to the backward step 141 (station 3). 144), and downstream of the backward step (station 4 145).

The pressure, temperature and velocity of the air entering the disclosed scramjet engine 100 changes as the air accelerates from Mach 5 to higher Mach numbers. This means that the shock waves and other characteristics of the hypersonic airflow within the scramjet engine 100 also change. The disclosed scramjet engine 100 has a fixed shape so that the shape or geometry of the scramjet engine 100 does not move throughout its length during hypersonic flight. To have a large operating Mach number range, fuel injection stations 142, 143, 144, 145 may be used individually or in various combinations and at various fuel metering levels by the disclosed scramjet engine 100. The combustion efficiency of the disclosed scramjet engine 100 can be maximized with the goal of combusting more than 80% of the oxygen in the trapped air.

The use of fuel injection stations 142, 143, 144, 145, individually or in combination, and at various fuel metering levels, varies depending on the flight Mach number. For example, at the top of the operating Mach range, where mixing between fuel and air is the greatest challenge, the fuel can be used to increase the mixing between fuel and air by utilizing the inlet length to increase the mixing between fuel and air at the total fuel metering level. is injected at station 1 142 on the body side 133 of the inlet 120 at a metering level of up to 50% of the fuel, and the remaining fuel is injected at station 2 143 upstream of the backward step 141 and at station 3 144 adjacent to the backward step 141. Will. In the middle portion of the operating Mach range, fuel is only present at station 2 143 upstream of backward step 141 and station 3 144 adjacent to backward step 141 at metering levels ranging from 40% to 60% of the total fuel metering from each station. Injected. At the lower end of the operating Mach range, injection of fuel upstream of the backward step 141 can create a large pressure rise in the disclosed scramjet engine 100, which can lead to engine misstart. . Therefore, fuel is injected at a combined metering level of less than 70% at station 2 143 upstream of backward step 141 and station 3 144 adjacent to backward step 141, and up to 30% at station 4 145 downstream of backward step 141. be done.

FIG. 3 illustrates one embodiment of a nozzle 160 of a scramjet engine 100 according to the present disclosure. As shown, nozzle 160 extends rearwardly from combustor 140. Nozzle 160 has a shape transition that expands from the rounded cross-sectional shape of combustor 140 to an exit shape 164 that smoothly integrates with hypersonic aircraft or vehicle 190 (not shown in FIG. 3). include. Nozzle 160 has a smoothly varying cross-sectional shape that increases in area along its length and terminates in exit shape 164 . Exit shape 164 can be tailored to meet the requirements for smooth integration with hypersonic aircraft or air vehicle 190. Other embodiments of the nozzle 160 with different exit shapes 164 allow for smooth airframe integration on hypersonic flying aircraft or air vehicles with curved or other aft body shapes.

Although the invention has been illustrated and described in several forms, it is to be understood that the invention is not intended to be limited to the particular forms disclosed. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following claims.

The methods disclosed herein include one or more steps or actions for implementing the described method. Method steps and/or actions may be interchanged with each other. In other words, the order and/or use of particular steps and/or actions may be changed, unless the particular order of steps or actions is required for proper operation of an embodiment.

References to approximations are made throughout this specification, such as by the use of the term "substantially." For each such reference, it is to be understood that in some embodiments the value, feature, or characteristic may be specified without approximation. For example, when modifiers such as "about" and "substantially" are used, these terms include within their scope the modified word in the absence of those modifiers. For example, when the term "substantially vertical" is described with respect to a configuration, it is understood that in further embodiments the configuration can have a precisely vertical configuration.

Similarly, in the above description of embodiments, various structures may be grouped together in a single embodiment, figure, or description thereof to simplify the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim requires more features than are expressly recited in the claim. Rather, as the following claims reflect, inventive aspects lie in combinations of less than all features of any single previously disclosed embodiment.

The claims following this written disclosure are hereby expressly incorporated into this written disclosure, with each claim standing on its own as a separate embodiment. This disclosure includes all modifications of the independent claims and their dependent claims. Furthermore, additional embodiments that can be derived from the following independent and dependent claims are also expressly incorporated herein.

Without further elaboration, it is believed that one skilled in the art, using the preceding description, can utilize the present invention to its fullest extent. The claims and embodiments disclosed herein are to be construed as merely illustrative and exemplary and in no way limit the scope of the disclosure. It will be apparent to those skilled in the art, with the aid of this disclosure, that changes may be made to the details of the embodiments described above without departing from the underlying principles of the disclosure herein. Dew. In other words, various modifications and improvements of the embodiments specifically disclosed in the above description are within the scope of the appended claims. Additionally, the order of steps or actions of the methods disclosed herein may be modified by those skilled in the art without departing from the scope of this disclosure. In other words, the order or use of specific procedures or acts may be varied, unless a particular order of steps or acts is required for proper operation of an embodiment. Accordingly, the scope of the invention is defined by the following claims and their equivalents.

Inlet 120 may be a mixed compression inlet. Capture shape 134 of inlet 120 is configured to provide external and internal air compression or deflation that allows scramjet engine 100 to self-start over its operating Mach range. Self-starting means that supersonic airflow is established through the scramjet engine 100 at the applicable hypersonic flight Mach number. If supersonic airflow is not established, scramjet engine 100 cannot generate thrust in the direction of motion in hypersonic flight conditions. Inlet 120 is configured to provide the necessary amount of airflow compression to enable as robust a combustion of fuel and air in combustor 140 as possible.

Claims (17)

an inlet, a combustor, and a nozzle, the capture shape of the inlet being configured to smoothly integrate with a forebody of a hypersonic aircraft or vehicle fuselage;
The outlet shape of the nozzle is configured to smoothly integrate with the aft body of a hypersonic aircraft or flying vehicle fuselage;
the scramjet engine geometry is fixed along the entire length of the scramjet engine;
scramjet engine. 2. The scramjet engine of claim 1, wherein the capture shapes of the inlet and outlet shapes of the nozzle are adjustable to smoothly integrate with the airframe of the hypersonic aircraft or vehicle. 3. The scramjet engine of claim 1 or 2, wherein the fixed shape includes a contracting and then expanding cross-sectional shape transition along the length of the scramjet engine. A scramjet engine according to any one of claims 1 to 3, wherein the scramjet engine is self-starting at a flight Mach number of Mach 5 or higher. the capture shape of the inlet is
a body-side leading edge attached directly to said front body of the fuselage of a hypersonic airplane or flying vehicle along its entire length;
a pair of side leading edges attached to the ends of the main body side leading edges protruding rearwardly at an angle of less than 90 degrees with respect to the front body of the hypersonic aircraft fuselage;
a pair of cowl front edges that protrude rearward and are attached to rear ends of the pair of side front edges that are joined at a cowling notch;
The scramjet engine according to any one of claims 1 to 4, comprising: the inlet includes a smooth constricting surface extending from the capture shape to a rounded inlet throat;
wherein the cross-sectional area of the throat is smaller than the cross-sectional area of the capture shape;
A scramjet engine according to any preceding claim, wherein the inlet is configured to capture and compress the airflow as it flows from a capture shape to the rounded inlet throat. . 7. The scramjet engine of claim 6, wherein the cowling notch is configured to exit the airflow from the inlet at flight speeds of Mach 5 or higher. 8. A scramjet engine according to claim 6 or 7, wherein the inlet is a mixed contraction inlet. A scramjet engine according to any one of claims 6 to 8, wherein the inlet comprises a first fuel injection station located downstream of a cowling notch. A scramjet engine according to any preceding claim, wherein the upstream end of the combustor connects directly to a rounded inlet throat. A scramjet engine according to any preceding claim, wherein all of the airflow captured by the inlet passes through the combustor. Any one of claims 1 to 11, wherein the combustor includes a rounded cross-sectional area along its entire length, the cross-sectional area increasing along the length of the combustor from an upstream end to a downstream end. The scramjet engine described in. 13. The scramjet engine of claim 12, wherein the combustor further comprises a backward step around the rounded cross-sectional area. The combustor is
a second fuel injection station located upstream of the backward facing step;
a third fuel injection station located adjacent to the rear facing step;
a fourth fuel injection station located downstream of the backward facing step;
The scramjet engine according to claim 12 or 13, further comprising: A scramjet engine according to any preceding claim, wherein the upstream end of the nozzle connects directly to the rounded downstream end of the combustor. A scramjet engine according to any preceding claim, wherein all of the air, fuel and combustion products exiting the combustor pass through the nozzle. the nozzle includes a smooth, expanding surface extending from a rounded upstream end to the exit shape;
a cross-sectional area of the upstream end is smaller than a cross-sectional area of the outlet shape;
17. The scramjet engine of claim 16, wherein the nozzle is configured to expand the air, fuel, and combustion products passing through the nozzle from the rounded upstream end to the outlet shape.

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