Sieve Rde Injector with Variable Pressure Drop Capability

The disclosure relates to rotating detonation engines and, more particularly, to structures and wall configuration defining the combustor of rotating detonation engines.

Rotating detonation engines are being considered for use to meet a wide variety of engine or propulsion needs. A rotating detonation engine (RDE) utilizes a controlled feed of fuel and oxidant to an annular chamber to generate a detonation wave rotating around the chamber at high speeds and produce thrust from an outlet of the chamber. Features for promoting fuel-oxidant mixing and maintaining a combustor pressure drop at various operating conditions are needed.

A combustor according to an example of this disclosure includes an inner wall, an outer wall, an end wall, and a valve element. The outer wall and the inner wall are spaced to form a combustion chamber, and the end wall joins the inner wall to the outer wall. A plurality of fuel ports extends through one of the inner wall and the outer wall. A plurality of oxidant openings extends through one or more of the inner wall, the outer wall, and the end wall. The valve element is arranged concentrically with one or more of the inner wall and the outer all and is translatable from a first position towards a second position and from the second position towards the first position. The valve element overlaps at least one oxidant opening as the valve element translates towards the second position.

A combustor assembly according to an example of this disclosure includes a case module and a combustor. The case module includes an inner case and an outer case. The combustor is disposed between the inner case and the outer case to form a plenum. The combustor includes an inner wall, an outer wall, an end wall, and a valve element. The outer wall and the inner wall are spaced to form a combustion chamber, and the end wall joins the inner wall to the outer wall. A plurality of fuel ports extends through one of the inner wall and the outer wall. A plurality of oxidant openings extends through one or more of the inner wall, the outer wall, and the end wall to fluidly connect the plenum to the combustion chamber. The valve element is arranged concentrically with one or more of the inner wall and the outer all and is translatable from a first position towards a second position and from the second position towards the first position. The valve element overlaps at least one oxidant opening as the valve element translates towards the second position.

is a cross-sectional view of combustorfor use with a rotating detonation engine (RTE). Combustorincludes inner wall, outer wall, end wall, fuel manifold, and valve element.

Combustorextends longitudinally along engine axis A within case module. Inner walland outer wallare spaced radially with respect to engine axis A to define combustion chamber. Inner walland outer wallcircumscribe engine axis A such that combustion chamberis annular. Inner wallis spaced radially outward from inner caseA of case moduleto define inner annular plenum. Outer wallis spaced radially inward from outer caseB of case moduleto define outer annular plenum. End wallextends between and joins inner wallto outer wallto define inlet endof combustor. Inner walland outer wallextend longitudinally along engine axis A to outlet end. Inner annular plenumand outer annular plenumreceive oxidant from inlet plenum, which defines a region between inner caseA and outer caseB that is upstream from end wall.

Fuel manifoldextends circumferentially along inner walland/or outer wallto enclose fuel plenum. Fuel plenumis placed in fluid communication with fuel source. Fuel portsextend through inner walland/or outer wallto place fuel plenumin fluid communication with combustion chamber. Fuel portsinclude one or more holes arranged in a circumferentially-spaces and/or axial spaced array of fuel ports. Fuel portscan be orientated normally with respect to a surface of inner wallor a surface of outer wallbounding combustion chamber. In other examples, fuel portscan be orientated at an oblique angle with respect to the combustion surface of inner wallor the combustion surface of outer wall. Fuel portsare depicted with a circular cross section. However, in other examples, fuel portscan be elliptical, ovular, oblong, square, or rectangular, among other possible cross-sections.

Combustorcan be restrained at inlet end, at outlet end, or at a location in between inlet endand outlet endof combustor. For example, a support structure may engage inner walland/or outer wallto restrain combustorradially and/or axially with respect to engine axis A. For example, support structurecan span between and connect inner wallor fuel manifoldto inner caseA, or span between and connect outer wallto outer caseB. The support structure may engage radially inner surfaceA and axial upstream surfaceB of fuel manifoldto restrain combustorin the radial and axial direction, respectively, with respect to engine axis A. Support structuremay include one or more struts, which can be used to supply fuel to fuel plenumthat span between fuel manifoldand inner caseA for example. In other examples, combustorcan be supported at or near outlet end. However, such examples may require cooling of the support structure to counteract heat flux produced by combustion.

At inlet endof combustor, inner wall, outer wall, and/or end wallcan include oxidant openings, which extend through respective portions thereof. Oxidant openingsplace inner annular plenum, outer annular plenum, and/or inlet plenumin fluid communication with combustion chamber. Example of oxidant openingscan include one or more holes, apertures, slots, and/or vanes, among other possible oxidant openings. Oxidant openingshave a hydraulic diameter sized to meter oxidant flow from inner annular plenum, outer annular plenum, and inlet plenuminto combustion chamber. In some examples, oxidant openingshave a length-to-hydraulic-diameter ratio (L/D) greater than 1.5. In other examples, the length-to-hydraulic-diameter ratio (L/D) is greater than 2.0. The cross-section of oxidant openingsare depicted as circular in,, and. In other examples, one or more oxidant openingscan have an elliptical, an ovular, an oblong, a rectangular, a diamond, a square cross-section, among other possible cross-sectional shapes. In still other examples, oxidant openingsare defined as oblong slots or aerodynamically shaped vanes as depicted inand.

Oxidant openingshave an angular orientation defined between an axis of each oxidant opening and a surface of inner wall, outer wall, or end wallbounding combustion chamber. In some examples, oxidant openingsare normal to a respective surfaces of inner wall, outer wall, or end wall. In other examples, oxidant openingsdefine an oblique angle with respect to a surface of inner wall, outer wall, or end wall. Oxidant openingswith an upstream orientation or a downstream orientation are angled to discharge into combustion chamberwith a velocity component towards outlet endor inlet end, respectively. Oxidant openingsmay have a clockwise orientation or a counterclockwise orientation in which oxidant openingsare oriented to discharge into combustion chamberwith a circumferentially clockwise velocity component or a circumferentially counterclockwise velocity component, when viewed along engine axis A towards outlet end. Oxidant openingscan be divided into one or more groups, each group characterized by a length-to-diameter ratio (L/D), angular orientation, number of openings, and/or pattern of openings.

Valve elementis a moveable member that translates along inner wallor outer wallto obstruct one or more oxidant openings, but less than all oxidant openings. Valve elementcan be a cylinder or ring disposed concentrically with respect to inner walland/or outer wall. In a first position (e.g., an open position), valve elementis offset from oxidant openingssuch that all oxidant openingsfluidly communicate with combustion chamberfrom one of inner annular plenum, outer annular plenum, and inlet plenum. In a second position (e.g., a closed position), valve elementis displaced axially along engine axis A relative to the first position to axially overlap and obstruct one or more oxidant openingsand less than all oxidant openings. In some examples, valve elementcan be positioned at any intermediate position between the first position and the second position. By covering or partially covering some or all of oxidant openings, valve elementcan vary a net oxidant inlet area into combustion chamberand, hence, vary a pressure drop and/or flow rate of oxidant flowing into combustion chamber. For instance, valve elementcan displace to vary a flow rate of oxidant into combustion chamberwhile maintaining a pressure drop associated with oxidant flow within a target pressure drop range.

Actuatorand, in some examples, linkagemay act together to translate valve element. Actuatorcan be any mechanical, electrical, hydraulic, pneumatic, or magnetic actuator suitable for use with combustor, among other possible actuator types. Actuatorcan be directly attached to valve elementin some examples and, accordingly, linkageis not necessary. In other examples, linkagecouples actuatorto valve elementusing any suitable mechanical, electrical, hydraulic, or pneumatic coupling such that movement of actuatortranslates to displacement of valve element.

Some examples of combustorare further associated with controller. Controlleris an electronic device that is connected to actuatorvia a wireless and/or a wired connection as indicated by dashed lines. Controllercan be a computer, an engine control unit, a control module integrated with an engine control unit, a control module discrete from an engine control unit, and a full authority digital engine (or electronics) controller, among other possible examples. While the following disclosure refers to a controller (singular), the functions attributed to a single controller can be distributed among multiple controllersin other examples. That is, functionality attributed herein to controllercan, in certain examples, be distributed among multiple controllers.

Controllercan store in memory a displacement schedule for valve elementthat relates an axial position of valve elementbetween the first position and the second position, inclusive, to one or more operating parameters of combustor, or a system or vehicle with which combustoris operatively associated. For instance, the displacement schedule can relate the position of valve elementrelative to one or more of altitude, ambient pressure, and/or ambient temperature. In other examples, controllercan receive signals representative of one or more internal parameters of combustor. For example, controller may receive a differential pressure signal representative of a pressure within combustion chamberrelative to a pressure within inlet plenum, inner annular plenum, and/or outer annular plenum. Likewise, controllermay receive multiple signals, each signal from a different pressure sensor. For example, combustormay include a first sensor configured to output a signal representative of a gauge pressure or an absolute pressure within combustion chamber. A second sensor or second sensors can be configured to each output a signal representative of a gauge pressure or ambient pressure within inlet plenum, inner annular plenum, and/or outer annular plenum. Based on the signals representative of pressure within combustion chamberand pressure within one or more of plenums,, and, controllermay calculate a differential pressure.

However determined, controllermay cause actuatorto translate valve elementto a target position based on a measured or calculated differential pressure described above in order to maintain the differential pressure within a target differential pressure range. The target differential pressure range can be associated with a minimum differential pressure necessary to prevent reverse propagation of the detonation wave during operation. A maximum differential pressure can be associated with a minimum flow rate required to maintain stable detonation wave propagation within combustion chamber.

In operation, combustoroperates within an oxidant mass flow rate range and a fuel flow rate range. Inlet plenum, inner annular plenum, and/or outer annular plenumreceive oxidant, which passively flows into combustion chamberthrough oxidant openings in one or more of inner wall, outer wall, and end wall. Fuel is received within fuel plenum, distributed circumferentially about combustor, and passively flows into combustion chambervia fuel ports. Fuel and oxidant mix within combustion chamberto achieve an oxidant-fuel ratio. Combustion initiates by, for example, activating an ignitor or otherwise introducing sufficient energy into combustion chamberto initiate combustion. Under continuous flow of oxidate and fuel into combustion chamber, a detonation wave develops within combustion chamberthat propagates circumferentially and axially throughout combustion chamber. As the oxidant-fuel mixture is consumed by the detonation wave and subsequent deflagration, additional oxidant and fuel passively refills combustion chamberthereby creating a continuously propagating detonation wave within combustion chamber. As flow rate of oxidant varies with changing ambient or operational conditions, valve elementcan reduce or increase the oxidant inlet area to maintain differential pressure into combustion chamberwithin a target range.

is a perspective section view of combustorA, andis a perspective end view of combustorA, depicting a particular example of combustoralong with additional details of oxidant openings. As depicted byand, combustorA includes multiple groups of oxidant openingsarranged through inner walland end wall. Outer wallof combustorA does not include any oxidant openings.

Inner wallincludes upstream oxidant openingsA and downstream oxidant openingsB located upstream and downstream relative to fuel portsrespectively. Upstream oxidant openingsA and downstream oxidant openingsB have an oblique orientation with respective to bounding surfaces of combustion chamber. Upstream oxidant openingsA are angled in a downstream clockwise direction. Downstream oxidant openingsB are angled in a downstream direction only.

Further as depicted, end wallincludes inner oxidant openingsC and outer oxidant openingsD. Inner oxidant openingsC have circular cross-sections and have an oblique orientation oriented in a clockwise orientation with respect to surface bounding combustion chamber. Outer oxidant openingsD have an oblique orientation angled in a counterclockwise direction.

Each of oxidant openingsA,B,C, andD have circular cross-sections and length-to-hydraulic-diameter ratios greater than 2.0, for example, a length-to-hydraulic-diameter ratio of about 2.4. In each instance, the oblique orientation of oxidant openingsA andB blocks all radial lines of sight between inner annular plenumand combustion chamber. Similarly, the oblique orientation of oxidant openingsC andD blocks axial lines of sight between inlet plenumand combustion chamber. Radially adjacent rows of oxidant openingsC andD and axially adjacent rows of oxidant openingsA andB are circumferentially offset to form respective grid patterns, which operate to promote mixing of oxidant and fuel within combustion chamber. Furthermore, upstream oxidant openingsA, inner oxidant openingsC, and outer oxidant openingsD define an alternating clockwise and counterclockwise orientation such that upstream oxidant openingsA are angled in a clockwise direction, inner oxidant openingsC are angled in a counterclockwise orientation, and outer oxidant openings are angled in a clockwise rotation. The alternating circumferential orientation of oxidant openingsA,C, andD creates shear layers between groups of oxidant openings and thereby promotes mixing of oxidant and fuel near inlet endof combustion chamber. In other examples, the alternating circumferential orientation can be reversed such that upstream oxidant openingsA and outer oxidant openingsD have a counterclockwise orientation and inner oxidant openingsC have a clockwise orientation.

Further as depicted byand, valve elementis a cylinder that has a first position (i.e., an open position) offset downstream from oxidant openingsB and fuel ports. Valve elementis translatable in an upstream direction along engine axis A to the second position (i.e., the blocked position) in which some of oxidant openingsB (e.g., three of four rows of oxidant openings) are covered by valve element. Likewise, valve elementis translatable in a downstream direction along engine axis A towards the first position. As such, the pressure drop of oxidant flowing into combustion chambercan be increased as valve elementtranslates from the first position to the second position, or decreased as valve elementtranslates from the second position to the first position. CombustorA can be associated with controlleras described above to vary the position of valve elementbased on a calculated or measured differential pressure, or based on a schedule that relate the position of valve elementto one or more external parameters (e.g., altitude, ambient temperature, and/or ambient pressure) and/or to one or more internal parameters (e.g., pressure and/or flow rate within combustion chamber, inlet plenum, inner annular plenum, and/or outer annular plenum, pressure and/or flow rate within fuel plenum, among other possible internal parameters).

is a perspective section view of combustorB, andis a perspective end view of combustorB, depicting another example of combustoralong with additional details of oxidant openings. As depicted byand, combustorB includes multiple groups of oxidant openingsarranged through inner walland end wall, each of the groups of oxidant openingshaving a slot configuration. Outer wallof combustorB does not include oxidant openings.

Inner wallincludes upstream oxidant openingsA and downstream oxidant openingsB located upstream and downstream relative to fuel portsrespectively. Upstream oxidant openingsA and downstream oxidant openingsB have an oblique orientation with respective to bounding surfaces of combustion chamber. Upstream oxidant openingsA are angled in a counterclockwise direction. Downstream oxidant openingsB are angled in a downstream direction.

Further as depicted, end wallincludes inner oxidant openingsC, outer oxidant openingsD, and intermediate oxidant openingsE. Inner oxidant openingsC are arranged proximate to inner wall(i.e., a radially innermost group of oxidant openings). Outer oxidant openingsD are arranged proximate to outer wall(i.e., a radially outermost group of oxidant openings). Intermediate oxidant openingsE are disposed radially between inner oxidant openingsC and outer oxidant openingsD. Inner oxidant openingsC and outer oxidant openingsD have an oblique orientation oriented in a clockwise orientation with respect to surface bounding combustion chamber. Upstream oxidant openingsA and intermediate oxidant openingsE have an oblique orientation angled in a counterclockwise direction.

Each of oxidant openingsA,B,C,D, andE have an oblong cross-section and length-to-hydraulic-diameter ratios greater than 2.0. In each instance, the oblique orientation of oxidant openingsA andB blocks all radial lines of sight between inner annular plenumand combustion chamber. Similarly, the oblique orientation of oxidant openingsC,D, andE blocks axial lines of sight between inlet plenumand combustion chamber. Upstream oxidant openingsA, inner oxidant openingsC, intermediate oxidant openingsE, and outer oxidant openingsD are slots with aerodynamically profiled sidewalls. That is to say, two opposite walls bounding oxidant openingsA,C,D, andE form airfoils having complimentary convex and concave flanks. As depicted, two opposite walls bounding downstream oxidant openingsB are parallel to a radial direction and, as such, are not aerodynamically shaped slots.

Furthermore, upstream oxidant openingsA, inner oxidant openingsC, intermediate oxidant openingsE, and outer oxidant openingsD define an alternating clockwise and counterclockwise orientation such that upstream oxidant openingsA and intermediate oxidant openingsE are angled in a counterclockwise direction while inner oxidant openingsC and outer oxidant openingsD are angled in a clockwise orientation. The alternating circumferential orientation of oxidant openingsA,C,D,E creates shear layers between groups of oxidant openings and thereby promotes mixing of oxidant and fuel near inlet endof combustion chamber. In other examples, the alternating circumferential orientation can be reversed such that upstream oxidant openingsA and intermediate oxidant openingsE have a clockwise orientation and inner oxidant openingsC and outer oxidant openingsD have a counterclockwise orientation.

Further as depicted byand, valve elementis a cylinder that has a first position (i.e., an open position) offset downstream from oxidant openingsD and fuel ports. Valve elementis translatable in an upstream direction along engine axis A to the second position (i.e., the blocked position) in which some of oxidant openingsB (e.g., two of three rows of slot-shaped oxidant openingsB) are covered by valve element. As depicted, valve elementis shown in the second position. Likewise, valve elementis translatable in a downstream direction along engine axis A towards the first position. As such, the pressure drop of oxidant flowing into combustion chambercan be increased as valve elementtranslates from the first position to the second position, or decreased as valve elementtranslates from the second position to the first position. CombustorB can be associated with controlleras described above to vary the position of valve elementbased on a calculated or measured differential pressure, or based on a schedule that relate the position of valve elementto one or more external parameters (e.g., altitude, ambient temperature, and/or ambient pressure) and/or to one or more internal parameters (e.g., pressure and/or flow rate within combustion chamber, inlet plenum, inner annular plenum, and/or outer annular plenum, pressure and/or flow rate within fuel plenum, among other possible internal parameters).

Accordingly, the foregoing examples provide a combustor for a rotating detonation engine that includes a variable oxidant inlet area. A variable oxidant inlet area facilitates operation of rotating detonation engine within a wider range of operational conditions characterized by one or more of ambient pressure, ambient temperature, oxidant mass flow rate, oxidant pressure, and oxidant temperature. Using valve elementto block and/or obstruct one or more oxidant openings, but less than all oxidant openings of combustor, controllercan cause combustion chamberto operate within a target differential pressure range and thereby maintain a stable detonation wave within combustion chamberdespite varying inlet conditions.

In the foregoing description, the terms “upstream” and “downstream” refer to the intended flow direction through combustors,A, andB, which flows from end walltowards outlet end. As depicted by, “upstream” refers to a direction generally towards end wallor the left side ofwhereas “downstream refers to a direction generally away from end wallor towards the right side of. Terms “inner” and “outer” refer to relative radial dimensions of combustorwith respect to engine axis A. “Axial” and “axially” refer to a direction parallel to engine axis A.

The following are non-exclusive descriptions of possible embodiments of the present invention.

A Combustor with Variable Oxidant Inlet Area

A combustor according to an example embodiment of this disclosure includes, among other possible things, an inner wall, an outer wall, an end wall, a plurality of fuel ports, a plurality of oxidant openings, and a valve element. The outer wall is spaced radially with respect to the inner wall to define a combustion chamber. The end wall joins the inner wall to the outer wall. The plurality of fuel ports extends through one of the inner wall and the outer wall. The plurality of oxidant openings extends through one or more of the inner wall, the outer wall, and the end wall. The valve element is disposed concentrically with one or more of the inner wall and the outer wall. The valve element is translatable from a first position towards a second position and from a second position towards a first position such that at least one oxidant opening of the plurality of oxidant openings as the valve element translates towards the second position.

The combustor of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components.

A further embodiment of the foregoing combustor, wherein the valve element can overlap less than all oxidant openings as the valve element translates towards the second position.

A further embodiment of any of the foregoing combustors can include a fuel plenum extending circumferentially about one of the inner wall and the outer wall and fluidly communicating with the plurality of fuel ports.

A further embodiment of any of the foregoing combustors, wherein the fuel ports can have an oblique orientation such that the fuel ports define one of a clockwise circumferential orientation and a counterclockwise circumferential orientation.

A further embodiment of any of the foregoing combustors, wherein at least some of the plurality of oxidant openings can have an oblique orientation that blocks line of sight into the combustion chamber when viewed along an engine axis and along a radial line relative to the engine axis.

A further embodiment of any of the foregoing combustors, wherein the plurality of oxidant openings can include upstream oxidant openings extending through the inner wall.

A further embodiment of any of the foregoing combustors, wherein the upstream oxidant openings can be disposed between the fuel ports and the end wall.

A further embodiment of any of the foregoing combustors, wherein the plurality of oxidant openings can include downstream oxidant openings extending through the inner wall.

A further embodiment of any of the foregoing combustors, wherein the downstream oxidant openings can be disposed between the fuel ports and an outlet end of the combustor opposite the end wall at an inlet end of the combustor.

A further embodiment of any of the foregoing combustors, wherein the upstream oxidant openings and the downstream oxidant openings can have a downstream orientation.

A further embodiment of any of the foregoing combustors, wherein the upstream oxidant openings can have one of clockwise downstream orientation and a counterclockwise downstream orientation.

A further embodiment of any of the foregoing combustors, wherein the plurality of oxidant openings can include inner oxidant openings extending through the end wall proximate inner wall.

A further embodiment of any of the foregoing combustors, wherein the plurality of oxidant openings can include outer oxidant openings extending through end wall proximate to outer wall.

A further embodiment of any of the foregoing combustors, wherein the outer oxidant openings can be radially outward from inner oxidant openings.

A further embodiment of any of the foregoing combustors, wherein one of the inner oxidant openings and the outer oxidant openings can have a clockwise orientation and the other of the inner oxidant openings and the outer oxidant openings can have a counterclockwise orientation.

A Combustor Assembly with a Variable Oxidant Inlet Area

A combustor assembly according to an example embodiment of this disclosure includes, among other possible things, a case module and a combustor. The case module includes an inner case and an outer case. The combustor is disposed between the inner case and the outer case to form a plenum. The combustor includes an inner wall, an outer wall, an end wall, a plurality of fuel ports, a plurality of oxidant openings, and a valve element. The outer wall is spaced radially with respect to the inner wall to form a combustion chamber. The end wall joins the inner wall to the outer wall. The plurality of fuel ports extends through one of the inner wall and the outer wall. The plurality of oxidant openings extends through one or more of the inner wall, the outer wall, and the end wall to fluidly connect the plenum to the combustion chamber. The valve element is disposed concentrically with one or more of the inner wall and the outer wall. The valve element is translatable from a first position towards a second position and from a second position towards a first position such that at least one oxidant opening of the plurality of oxidant openings as the valve element translates towards the second position.

The combustor assembly of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components.