EP4689376A1

EP4689376A1 - Zero emission subsonic turbofan engine

Info

Publication number: EP4689376A1
Application number: EP23931913.0A
Authority: EP
Inventors: Pramod VADITYA; Anil Kumar Kommagalla VELDI; Abhijeet INAMDAR; Purandar CHAKRAVARTY
Original assignee: Sirinor AS
Current assignee: Sirinor AS
Priority date: 2023-04-03
Filing date: 2023-08-11
Publication date: 2026-02-11
Also published as: WO2024209482A1

Abstract

Electric turbofan engine includes a housing and an exhaust nozzle. Plurality of fans are arranged in an axial. A turbine having a plurality of turbine blades and being arranged and coupled to a fan in a radial direction. A first set and a second set of radial compressors are located radially from the turbine and are operable to drivingly rotate the turbine, which in turn rotates the fan. Plurality of electric motors are included, and each of the plurality of electric motors are coupled to a respective one of the plurality of radial compressors and drivingly rotating the respective radial compressor.

Description

ZERO EMISSION SUBSONIC TURBOFAN ENGINE

FIELD

[0001] The present disclosure generally relates to an apparatus and method for flying an air vehicle using turbofan engine at speed near the speed of sound or high subsonic speeds while generating no emissions during flight.

BACKGROUND

[0002] Current technology in the subsonic travel space requires the burning of fossil fuels to power engines to drive the flying vehicle. Technology being developed includes batteries that available to power engines using stored electrical capacity. Additionally, other technologies that are being developed include burning different types of fuels to reduce the emissions during flight.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Implementations of the present technology will now be described, by way of example only, with reference to the attached figures, wherein:

[0004] FIG. 1 is a side view and diagrammatic example of an electric engine of a flying vehicle having speeds near than the speed of sound according to at least one instance of the present disclosure;

[0005] FIG. 2 is a sectional view of FIG. 1, according to at least one instance of the present disclosure;

[0006] FIG. 3 is a front view of FIG. 1, according to at least one instance of the present disclosure;

[0007] FIG. 4 is a detailed view of an example of a turbine and fan including an exploded view of a turbine blade and a fan blade, according to at least one instance of the present disclosure;

[0008] FIG. 5A is a side view of an example of a turbine-fan assembly, according to at least one instance of the present disclosure;

[0009] FIG. 5B is a cross sectional view taken along section line A-A of FIG. 5A, according to at least one instance of the present disclosure; [0010] FIG. 6 is a diagrammatic view of a radial compressor and turbine, according to at least one instance of the present disclosure; and

[0011] FIG. 7 is a diagrammatic representation of an example system, according to at least one instance of the present disclosure.

DETAILED DESCRIPTION

[0012] Examples and various features and advantageous details thereof are explained more fully with reference to the exemplary, and therefore non-limiting, examples illustrated in the accompanying drawings and detailed in the following description. Descriptions of known starting materials and processes can be omitted so as not to unnecessarily obscure the disclosure in detail. It should be understood, however, that the detailed description and the specific examples, while indicating the preferred examples, are given by way of illustration only and not by way of limitation. Various substitutions, modifications, additions and/or rearrangements within the spirit and/or scope of the underlying inventive concept will become apparent to those skilled in the art from this disclosure.

[0013] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, product, article, or apparatus that comprises a list of elements is not necessarily limited only those elements but can include other elements not expressly listed or inherent to such process, process, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0014] Additionally, any examples or illustrations given herein are not to be regarded in any way as restrictions on, limits to, or express definitions of, any term or terms with which they are utilized. Instead, these examples or illustrations are to be regarded as being described with respect to one particular example and as illustrative only. Those of ordinary skill in the art will appreciate that any term or terms with which these examples or illustrations are utilized encompass other examples as well as implementations and adaptations thereof which can or cannot be given therewith or elsewhere in the specification and all such examples are intended to be included within the scope of that term or terms. Language designating such non-limiting examples and illustrations includes, but is not limited to: “for example,” “for instance,” “e.g.,” “In some examples,” and the like.

[0015] Although the terms first, second, etc. can be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present inventive concept.

[0016] The present disclosure generally relates to a true zero emission engine designed for flying vehicle having speeds near the speed of sound. A true zero emission engine as referred herein means that there is no emissions at the engine exhaust. Other engines being developed have excess NOx emissions, low carbon emissions, NOx emissions, and/or particulate matter emissions. One of the differences between the present disclosure and conventional engines is the operation for flying at high subsonic speeds. Another difference between the present disclosure and conventional engines is the source of power. In at least one example, the presently disclosed engine can be operable to run on compressed air. As detailed below, the compressed air can be generated from electric powered compressors. The presently disclosed engine can implement a turbine coupled to a fan in combination with the compressed air or separately therefrom. The turbine can be mechanically coupled to the fan such that the turbine and the fan rotate in opposite directions. In at least one example, they can be coupled through a planetary gear mechanism or other counter rotating mechanisms that allow the turbine to rotate the respective fan. In at least one example, the engine is designed to power the vehicle without any combustion and without emitting any pollutants.

[0017] The turbine can operate based upon reaction force produced by the compressed air that is produced on board using radial compressors. The radial compressors can be centrifugal compressors. The present disclosure, in at least one example, uses a contra rotating tip turbine powered fan for high-velocity thrust. In at least one example, the present disclosure utilizes a solid fan blade that does not include any hollowed portions. Additionally, the present disclosure can include high reaction turbine blades that are also solid without any hollow portion. The compressed air can drive the turbine by the expansion of the compressed air. The compressed air can be produced by a centrifugal compressor, which is powered electrically.

[0018] As described above, the present technology does not emit any pollutants. Additionally, the present technology can have one or more of the following advantages: less heat being added into the atmosphere as compared to conventional technology, reduced complexity in operation of the engine as compared to conventional technology, and/or reducing the risk factor of explosion and fire hazards as compared to conventional technology.

[0019] FIG. 1 is a side view and diagrammatic example of an electric engine 100 of a flying vehicle, such as a jet airplane, capable of flying at speeds near the speed of sound according to at least one instance of the present disclosure. The vehicle as presented herein can also be described as a subsonic flying vehicle. The engine 100 includes a housing 2, an inlet 102, and an exhaust nozzle 18.

[0020] FIG. 2 is a sectional view of FIG. 1, according to at least one instance of the present disclosure. The engine 100 can start by powering electric motors 10, 24, 39, 68 that are coupled to a respective one of the radial compressors 8, 69, 48, 28. In at least one example, the electric motors 10, 24, 39, 68 can be coupled to the respective one of the radial compressors 8, 69, 48, 28 by a shaft 86, 62 see FIG. 6. In other examples, the electric motors 10, 24, 39, 68 can be directly connected to the respective one of the radial compressors 8, 69, 48, 28. The electric motors 10, 24, 39, 68 can powered electrically from an onboard source of electricity such as a fuel cell or battery as will be explained in regards to FIG. 7 below. The radial compressors 8, 69, 48, 28 can act as the engine control unit. The radial compressors 8, 69, 48, 28 act as an engine control unit by adjusting the flow of air to the turbine 42. The radial compressors 8, 69, 48, 28 are equipped with Guided Flow Channels (GFC) 3 for air intake. In at least one example, there can be a plurality of radial compressors, and each of the plurality of radial compressors can have a corresponding single GFC 3. [0021] The plurality radial compressors 8 can be superior to axial compressors in producing high-pressure per single stage and occupy less volume to deliver the same amount of pressure. As illustrated, a series of radial compressors 8, 69, 48, 28 can be arranged around the circumference of the secondary duct 1. The secondary duct 1 can be a single flow channel or be made of a plurality of flow channels. Additionally, in at least one instance, a first secondary flow channel 1 can be used to feed air to the first set of radial compressors 8, 28 and a flow channel 74 can be used to feed air to second set of radial compressors 69, 48. The Guided Flow Channels (GFC) 3 can be formed in the housing 2 and create a dedicated separate air intake for each radial compressor 8, 28.

[0022] As presented, a fan 36 is provided, namely a primary fan 36. The primary fan 36 is the only fan 36 that is coupled to a turbine 42. Additionally, a secondary fan 99 is contra-rotating as compared to the primary fan 36. The secondary fan 99 has no turbine coupled thereto and the secondary fan 99 can be driven by the primary fan 36. Contrarotating refers to rotating in a direction that is opposite the other direction. For example, the primary fan can rotate clockwise and the secondary fan can rotate counter-clockwise. In at least one example, the primary fan 36 is located closer to the intake as compared to the secondary fan 99.

[0023] The exhaust air can pass through the exhaust nozzle 18, which in the illustrated example can be a convergent nozzle. The exit air velocities can be faster than speed of sound, for example in the range of 1 Mach to 1.5 Mach. In other examples, the speed of the air at the exit can be less than the speed of sound. The whole system is axially arranged and strengthened by stationary structures or vanes 87, 53.

[0024] The above description provides for how the flow of air operates through the engine. Some additional details are given with respect to FIG. 6 below as well. Further details on the subsonic jet engine 100 are provided herein as well. The subsonic jet engine 100 includes a housing 2 having an inlet 102 and an exhaust nozzle 18. As described above, air enters the engine 100 through the inlet 102 and exits the engine 100 at the exhaust nozzle 18.

[0025] The jet engine includes an inlet 102. The engine 100 includes a first fan 36 and a second fan 99 arranged in an axial direction 110 within the housing 2. The first fan 36 can be located upstream from the second fan 99, such that the second fan 99 is closer to the exhaust nozzle 18 than the first fan 36. Therefore, the first fan 36 can be closer to the inlet 102 than the second fan 99. Each of the fans 36, 99 includes a plurality of fan blades 352. The fan blades 352 can be shaped as described in relation to FIG. 4 below. In at least one example, the fan blades 352 can be carbon fiber and with titanium leading edge fan blades. In other examples, different types of fan blades can be implemented as well, for example with complete titanium blade or with completely carbon fiber. A first set of stationary vanes 87 can also be located before the first fan 36, and a second set of stationary vanes 53 can be located after the second fan 99. The first set of stationary vanes 53 can be located upstream from the first fan 36. The second set of stationary vanes 53 can be located downstream from the second fan 99.

[0026] The engine 100 includes a turbine 42. The turbine 42 can have a plurality of turbine blades 77. The turbine 42 can be arranged and coupled to the first fan 36 in a radial direction 130. As illustrated a single turbine 42 is included. The single turbine 42 is only coupled to the first fan 36.

[0027] The engine 100 includes a plurality of radial compressors 8, 69, 48, 28 located radially from the turbine 42. Each of the plurality of radial compressors 8, 69, 48, 28 are operable to drivingly rotate the turbine 42, which in turn rotates the primary or first fan 36. The plurality of radial compressors 8, 69, 48, 28 comprises a first set of radial compressors 8 and a second set of radial compressors 69, wherein the first set of radial compressors 8 are operable to compress the air in the first compression which is then fed in to the second set of radial compressors 69 are operable to rotate the turbine 42. Thus, each of the second set compressors 69 is operable to receive output from a respective one of the first set of radial compressors 8. In at least one configuration, the first set of radial compressors 8 is located in a forward axial direction 110 compared to the second set of radial compressors 69. The second set of compressors 69 has an output that is operable to driving rotate the turbine 42. The turbine 42 can rotate in a first direction along with the primary fan 36 which is coupled to a gearbox 786. There second fan 99 operable by gearbox 786 and rotates in the second direction. The gearbox 785 can include gearing to reverse the direction of rotation and maintain substantially the same rotational speed of the second fan relative to the first fan. The second fan 99 rotates in a second direction that is contra to the first direction. [0028] The engine 100 includes a plurality of electric motors 10, 24, 68, 39. Each of the plurality of electric motors 10, 24, 68, 39 can be coupled to a respective one of the plurality of radial compressors 8, 69, 48, 28 and drivingly rotating the respective radial compressor 8, 69, 48, 28. The engine 100 can include a first set of stationary vanes 87 that span from an interior 160 of the housing 2 to support the main shaft 32. In at least one example, the first set of stationary vanes 87 can span from the interior 160 to an exterior 162 of the housing 2, but not penetrate the exterior 162 of the housing 2.

[0029] FIG. 3 is a front view of FIG. 1, according to at least one instance of the present disclosure. The housing 2 forms a plurality of GFC’s 3 (see FIG. 2) that extend from a respective one of the plurality of intake channels to a respective one of the plurality of radial compressors (see FIG. 2).

[0030] FIG. 4 is a detailed view of an example of a turbine 42 and fan 36 including exploded views of a turbine blade 77 and fan blade 352, according to at least one instance of the present disclosure. FIG. 4 is a detailed view of turbine 42, according to at least one instance of the present disclosure. The tip turbine 42 is very efficient compared to conventionally driving the fan 36 from the turbine 42 because there is no shaft, thus there is nothing lost as shaft work in the tip of the turbine 42. All necessary methods will be followed to reduce pneumatic losses in compressor and turbine by means of using cascades, seals and precise design. The noise suppression design and combustion elimination provide for about 60% reduction in noise compared to conventional high speed air vehicle engines.

[0031] FIG. 5A is a side view of an example of a turbine 42, according to at least one instance of the present disclosure. The shroud casing 20 which is connecting turbine blades 77 and the fan blades 352 is an aerodynamic stiffener which helps to reduce the energy required to drive the fan 36 by creating additional inertial momentum at the tip, by following the principle of lever-arm effect, the force required to turn the fan 36 is reduced. The fan blade 352 is the new generation fan blade design which is a more efficient air driver manufactured using titanium.

[0032] FIG. 5B is a cross sectional view of FIG. 5A, according to at least one instance of the present disclosure. Casing 20 shrouds the fan blades 352, the casing 20 provides stiffness to the fan, makes it structurally stable and provides more inertial momentum while rotating compared to conventional fan. To further accelerate the flow of air, the engine is equipped with counter-rotating fan that is placed just behind the primary fan. The fan blades 352 can be coupled to shaft 245.

[0033] FIG. 6 is a diagrammatic view of a radial compressor and turbine, according to at least one instance of the present disclosure. The respective one of the plurality of radial compressor 8 is located at an exit end 256 of the GFC 3 and air flows from the GFC 3 through the respective one of the radial compressors 8 and then to turbine 77.

FIG. 6 is a detailed view of the secondary duct 1 including a GFC 3 for the first stage fan. The air is moved by a compressor 8 which is driven by an electric motor 10 through a shaft 86, that compressed air is then ejected into volute 5 which connects to a coupling duct 74 that transfers the compressed air between a first compressor 8 and a second compressor 69. The second compressor 69 ejects the air on turbine 77 via an ejector nozzle 98 connected to volute 54. The compressed air can then expand through ejector nozzle which is attached to the compressor volute 54 onto the turbine blades 77, which are aerodynamic and/or designed to produce high torque and rapid air expansion. The turbine blades 77 can be fixed around fan casing 20. The rotation of the turbine 77 created by the expansion of air results in speeds near the speed of sound.

[0034] The respective one of the plurality of radial compressors 8 is located at an exit end 256 of the secondary flow channel 3 and air flows from the secondary flow channel 3 through the respective one of the radial compressors 8 and then to a respective one of the plurality of second stage radial compressors 69. The respective one of the plurality of radial compressors 69 is located at an exit end 748 of the flow channel 74 and air flows from the flow channel 74 through the respective one of the radial compressors 69 and then to a respective one of the plurality of turbines 42. Thus, a first set of compressors 8, 28 are provided along with a second set of compressors 69, 48. The first set of compressors 8, 28 is configured in an upstream orientation to the second set of compressors 69, 48. The arrangement of two compressors in series allows for increased airflow to the turbine 42. The turbine 42 can provide the motive force for the fan 36.

[0035] A contra rotating fan 99 is placed behind the first fan 36 to increase the pressure and velocity of the mass flow. A gearbox 786 is used to connect first fan 36 and second fan 99. The high pressure compressed air expands through exhaust nozzle 18 creating a high thrust.

[0036] FIG. 7 is a diagrammatic representation of an example system, according to at least one instance of the present disclosure. As described above, the engine integration is a radially driven turbine with counter rotating fan, exit convergent nozzle. The fuel source of hydrogen is converted to electricity by the multi-stack fuel cell by also using oxygen that is concentrated prior to being sent by the radial compressor located inside engine. The radial compressor has the advantage of producing high pressure in a single stage that can reduce the drag in front of the fan and make the engine cowl an aerodynamic design. The excess fluid coming out of the fuel cell system then can be sent to the radial compressor that can help to increase the density of the inlet fluid, which can increase the compressor and turbine efficiency.

[0037] The source of power is electrical power, for example produced onboard using hydrogen as a fuel. Other sources of electrical power are also considered within the scope of this application including but not limited to batteries, chemical sources, nuclear power, and/or capacitor type storage. The controlling unit of the above-mentioned engine is electrical resistance, compressor revolutions per minute (RPM) and the inlet fluid density. The engine could be also modified as combustion driven engine by introducing a combustion chamber between the radial compressor exit and turbine, even in this case the fuel can be hydrogen for combustion.

[0038] The illustrated example provides an electric turbofan engine system 101 can include a source of hydrogen 200. In at least one example, the source of hydrogen 200 can be a compressed tank of hydrogen gas. The system 101 can include a multi-stack fuel cell 210 coupled to the source of hydrogen 200. In one example, the multi-stack fuel cell 210 can be coupled to the source of hydrogen though a gas line 202 that is coupled to a header 204 that has individual runs 206 for each fuel cell within the multi-stack fuel cell 210.

[0039] Additionally, an oxygen concentrator 220 can be coupled to the multi- stack fuel cell 210. In at least one example, the oxygen concentrator 220 can be coupled to the multistack fuel cell 210 through one or more gas lines 222. In at least one example, a header 224 is implemented that branches out into individual lines 226 to feed the respective one of the fuel cells within the multi-stack fuel cell 210. [0040] The oxygen concentrator 220 can also be coupled to the engine 100. A pump 230 can further be located between the oxygen concentrator 220 and the engine 100. The pump 230 can apply positive pressure beyond what is available from the engine 100. Additionally, check valves and/or one-way valves can be provided to prevent backflow. Excess fluid can be returned through a line 240 to the engine 100 for expulsion. In at least one example, the excess fluid is in the form of water and/or water vapor.

[0041] The system 101 can include an electrical load management system 252 coupled to the multi-stack fuel cell 210. The electrical load management system 252 can be coupled though one or more electrical lines 250 to the engine 100 and the multi-stack fuel cell 210.

[0042] The system 101 can include a subsonic electric turbofan engine 100 operable to receive electrical power from the electrical load management system 252, wherein the electrical power drives a plurality of electric motors that rotates a plurality of radial compressors of the turbofan engine and thereby rotate a plurality of fans within the electric turbofan engine 100. The turbofan engine 100 of the electric turbofan engine system can include one or more features of the engine 100 described herein.

[0043] While the above illustration is in regards to hydrogen based electrical power generation, other onboard electric sources could be implemented instead includes those described above.

[0044] The embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size and arrangement of the parts within the principles of the present disclosure to the full extent indicated by the broad general meaning of the terms used in the attached claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the appended claims.

[0045] Illustrative examples of the disclosure include:

[0046] Aspect 1: An electric turbofan engine comprising: a housing having an inlet and an exhaust nozzle; a first fan arranged in an axial direction within the housing and including a plurality of fan blades; a second fan arranged in an axial direction within the housing and coupled to the first fan, wherein the first fan is located upstream from the second fan, such that the second fan is closer to the exhaust nozzle than the first fan; a turbine having a plurality of turbine blades and being arranged and coupled to the first fan in a radial direction; a first set of radial compressors located radially in the housing; a second set of radial compressors located radially in the housing, and each of the second set compressors operable to receive output from a respective one of the first set of radial compressors, wherein the second set of compressors output is operable to drivingly rotate the turbine, which in turn rotates the first fan; a plurality of electric motors, each of the plurality of electric motors coupled to a respective one of the first set and the second set of radial compressors and drivingly rotating the respective radial compressor.

[0047] Aspect 2: The electric turbofan engine of Aspect 1, wherein the housing forms a plurality of flow channel inlets and a plurality of flow channels that extend from a respective one of the plurality of flow channel inlet to a respective one of the first set of radial compressors.

[0048] Aspect 3: The electric turbofan engine of Aspect 2, wherein the respective one of the plurality of radial compressors is located at an exit end of the flow channel and air flows from the flow channel through the respective one of the radial compressors and then to a respective one of the second set of radial compressors.

[0049] Aspect 4: The electric turbofan engine of Aspect 3, wherein the first set of radial compressors are located in a forward axial direction compared to the second set of radial compressors, which are located before the turbine.

[0050] Aspect 5: The electric turbofan engine of any one of Aspects 1-5, wherein the first fan rotates in a first direction and the second fan rotates in a second direction that is contra to the first direction.

[0051] Aspect 6: The electric turbofan engine of Aspect 5, wherein the first fan is coupled to the second fan through a gearbox.

[0052] Aspect 7: The electric turbofan engine of Aspect 6, wherein the gearbox includes gearing to reverse the direction of rotation and maintain a same rotational speed of the second fan relative to the first fan. [0053] Aspect 8: The electric turbofan engine of any one of Aspects 1-7, wherein the exhaust nozzle is convergent.

[0054] Aspect 9: The electric turbofan engine of any one of Aspect 1-8, further comprising a first set of stationary vanes that span from an interior of the housing to support a main shaft.

[0055] Aspect 10: The electric turbofan engine of Aspect 9, wherein the first set of stationary vanes is located upstream from the first fan.

[0056] Aspect 11: The electric turbofan engine of Aspect 10, further comprising a second set of stationary vanes that are located downstream from the second fan.

[0057] Aspect 12: An electric turbofan engine system comprising: a source of hydrogen; a multi- stack fuel cell coupled to the source of hydrogen; an oxygen concentrator coupled to the multi-stack fuel cell; an electrical load management system coupled to the multistack fuel cell; an electric turbofan engine operable to receive electrical power from the electrical load management system; a housing having an inlet and an exhaust nozzle; a first fan arranged in an axial direction within the housing and including a plurality of fan blades; a second fan arranged in an axial direction within the housing and coupled to the first fan, wherein the first fan is located upstream from the second fan, such that the second fan is closer to the exhaust nozzle than the first fan; a turbine having a plurality of turbine blades and being arranged and coupled to the first fan in a radial direction; a first set of radial compressors located radially in the housing; a second set of radial compressors located radially in the housing, and each of the second set compressors operable to receive output from a respective one of the first set of radial compressors, wherein the second set of compressors output is operable to drivingly rotate the turbine, which in turn rotates the first fan; a plurality of electric motors, each of the plurality of electric motors coupled to a respective one of the first set and the second set of radial compressors and drivingly rotating the respective radial compressor, wherein the electrical power drives the plurality of electric motors.

[0058] Aspect 13: The electric turbofan engine system of Aspect 12, wherein the housing forms a plurality of flow channel inlets and a plurality of flow channels that extend from a respective one of the plurality of flow channel inlet to a respective one of the first set of radial compressors, and the respective one of the plurality of radial compressors is located at an exit end of the flow channel and air flows from the flow channel through the respective one of the radial compressors and then to a respective one of the second set of radial compressors.

[0059] Aspect 14: The electric turbofan engine system of Aspect 13, wherein the first set of radial compressors are located in a forward axial direction compared to the second set of radial compressors, which are located before the turbine.

[0060] Aspect 15: The electric turbofan engine system of any one of Aspects 12-14, wherein the first fan rotates in a first direction and the second fan rotates in a second direction that is contra to the first direction.

[0061] Aspect 16: The electric turbofan engine system of Aspect 15, wherein the first fan is coupled to the second fan through a gearbox.

[0062] Aspect 17: The electric turbofan engine system of Aspect 16, wherein the gearbox includes gearing to reverse the direction of rotation and maintain a same rotational speed of the second fan relative to the first fan.

[0063] Aspect 18: The electric turbofan engine system of any one of Aspects 12-17, further comprising a first set of stationary vanes that span from an interior of the housing to support a main shaft.

[0064] Aspect 19: The electric turbofan engine system of Aspect 18, wherein the first set of stationary vanes is located upstream from the first fan.

[0065] Aspect 20: The electric turbofan engine system of Aspect 19, further comprising a second set of stationary vanes that are located downstream from the second fan.

Claims

CLAIMS:

1. An electric turbofan engine comprising: a housing having an inlet and an exhaust nozzle; a first fan arranged in an axial direction within the housing and including a plurality of fan blades; a second fan arranged in an axial direction within the housing and coupled to the first fan, wherein the first fan is located upstream from the second fan, such that the second fan is closer to the exhaust nozzle than the first fan; a turbine having a plurality of turbine blades and being arranged and coupled to the first fan in a radial direction; a first set of radial compressors located radially in the housing; a second set of radial compressors located radially in the housing, and each of the second set of radial compressors operable to receive output from a respective one of the first set of radial compressors, wherein the second set of radial compressors output is operable to drivingly rotate the turbine, which in turn rotates the first fan; a plurality of electric motors, each of the plurality of electric motors coupled to a respective one of the first set and the second set of radial compressors and drivingly rotating the respective radial compressor.

2. The electric turbofan engine of claim 1, wherein the housing forms a plurality of flow channel inlets and a plurality of flow channels that extend from a respective one of the plurality of flow channel inlets to a respective one of the first set of radial compressors.

3. The electric turbofan engine of claim 2, wherein the respective one of the plurality of radial compressors is located at an exit end of the flow channel and air flows from the flow channel through the respective one of the radial compressors and then to a respective one of the second set of radial compressors.

4. The electric turbofan engine of claim 3, wherein the first set of radial compressors are located in a forward axial direction compared to the second set of radial compressors, which are located before the turbine.

5. The electric turbofan engine of claim 1, wherein the first fan rotates in a first direction and the second fan rotates in a second direction that is contra to the first direction.

6. The electric turbofan engine of claim 5, wherein the first fan is coupled to the second fan through a gearbox.

7. The electric turbofan engine of claim 6, wherein the gearbox includes gearing to reverse a direction of rotation and maintain a same rotational speed of the second fan relative to the first fan.

8. The electric turbofan engine of claim 1, wherein the exhaust nozzle is convergent.

9. The electric turbofan engine of claim 1, further comprising a first set of stationary vanes that span from an interior of the housing to support a main shaft.

10. The electric turbofan engine of claim 9, wherein the first set of stationary vanes is located upstream from the first fan.

11. The electric turbofan engine of claim 10, further comprising a second set of stationary vanes that are located downstream from the second fan.

12. An electric turbofan engine system comprising: a source of hydrogen; a multi-stack fuel cell coupled to the source of hydrogen; an oxygen concentrator coupled to the multi-stack fuel cell; an electrical load management system coupled to the multi-stack fuel cell; an electric turbofan engine operable to receive electrical power from the electrical load management system; a housing having an inlet and an exhaust nozzle; a first fan arranged in an axial direction within the housing and including a plurality of fan blades; a second fan arranged in an axial direction within the housing and coupled to the first fan, wherein the first fan is located upstream from the second fan, such that the second fan is closer to the exhaust nozzle than the first fan; a turbine having a plurality of turbine blades and being arranged and coupled to the first fan in a radial direction; a first set of radial compressors located radially in the housing; a second set of radial compressors located radially in the housing, and each of the second set of radial compressors operable to receive output from a respective one of the first set of radial compressors, wherein the second set of radial compressors output is operable to drivingly rotate the turbine, which in turn rotates the first fan; a plurality of electric motors, each of the plurality of electric motors coupled to a respective one of the first set and the second set of radial compressors and drivingly rotating the respective radial compressor, wherein the electrical power drives the plurality of electric motors.

13. The electric turbofan engine system of claim 12, wherein the housing forms a plurality of flow channel inlets and a plurality of flow channels that extend from a respective one of the plurality of flow channel inlets to a respective one of the first set of radial compressors, and the respective one of the plurality of radial compressors is located at an exit end of the flow channel and air flows from the flow channel through the respective one of the radial compressors and then to a respective one of the second set of radial compressors.

14. The electric turbofan engine system of claim 13, wherein the first set of radial compressors are located in a forward axial direction compared to the second set of radial compressors, which are located before the turbine.

15. The electric turbofan engine system of claim 12, wherein the first fan rotates in a first direction and the second fan rotates in a second direction that is contra to the first direction.

16. The electric turbofan engine system of claim 15, wherein the first fan is coupled to the second fan through a gearbox.

17. The electric turbofan engine system of claim 16, wherein the gearbox includes gearing to reverse a direction of rotation and maintain a same rotational speed of the second fan relative to the first fan.

18. The electric turbofan engine system of claim 12, further comprising a first set of stationary vanes that span from an interior of the housing to support a main shaft.

19. The electric turbofan engine system of claim 18, wherein the first set of stationary vanes is located upstream from the first fan.

20. The electric turbofan engine system of claim 19, further comprising a second set of stationary vanes that are located downstream from the second fan.