Description:FIELD OF THE INVENTION
The present invention relates to hydrogen-fuel internal combustion engines, particularly to a novel annular rotary engine configuration achieving continuous combustion, superior thermal regeneration, and mechanical torque generation through quadrant-based piston expansion cycles.
BACKGROUND OF THE INVENTION
Existing hydrogen engines largely rely on reciprocating piston mechanisms or modified Wankel-type rotaries. These engines face limitations in combustion continuity, heat reuse, and compact integration. Conventional IC engine designs suffer from significant thermal losses, incomplete fuel mixing, and low mechanical efficiency. There remains an unmet need for a compact hydrogen engine with:
• Continuous combustion
• Enhanced hydrogen-air mixing
• Regenerative heat recovery
• Compact form and modular scalability
• Efficiency exceeding 50%
SUMMARY OF THE INVENTION
The present invention discloses a high-efficiency annular rotary engine powered by hydrogen, featuring fully tangential fuel and air injection, quadrant-based combustion cycles, and integrated spiral air compression. The engine comprises a single or multiple annular combustion disks mounted on a central shaft, each disk incorporating curved piston grooves along which oval or round pistons rotate. The combustion chamber sequence includes a tangential vortex fuel mixing chamber, an annular combustion chamber, and a spiral coil functioning as a regenerative air compressor.
Fuel mixing occurs in a vortex chamber that shares a thermally conductive wall with the combustion disk, utilizing radiative heat to preheat the hydrogen-air mixture. Compressed ambient air is generated via a rotating spiral coil and delivered through a rotary-fixed union assembly to tangential injectors.
Quadrant-based combustion enables either single or dual-cycle operation per revolution, and a continuous exhaust port creates a deliberate pressure gradient that enhances rotational torque. The engine achieves over 50% thermal efficiency with compact integration, making it suitable for clean propulsion and industrial energy systems.
FIGURE DESCRIPTION
Figure 1: Exploded 3D schematic view of the high-efficiency hydrogen annular rotary engine, illustrating key integrated components:
• Annular rotary combustion chambers featuring quadrant-based piston operation
• Centrifugal vortex preheating chamber for hydrogen-air fuel mixture
• Spiral-type air compressor coil concentrically coupled to the drive shaft
• Rotary-fixed union assembly with multi-port tangential air injection nozzles
• Radial air supply channels routed to the preheating chamber
• Hydrogen and air inlet ports, combustion exhaust outlet ports, and integrated air filtration units
• Structural frame and mounting supports for engine assembly alignment and casing integration
Figure2: Front sectional view of the annular rotary combustion chamber illustrating the piston-guided annular cam track integrated into the rotary disk.
Figure 2A: Illustration of a four-quadrant operational configuration, sequence of operation includes injection, combustion, expansion, and exhaust carried out in quadrant 1-2-3-4.
Figure 2B: Illustration of an eight- quadrant operational configuration, dual cycle mode- a sequence of operation includes injection, combustion, expansion, and exhaust carried out in quadrant 1-2-3-4 and 5-6-7-8.
Figure 3: Tangential Vortex Fuel Mixing Chamber
Figure 3a (Front View): This schematic shows the front elevation of the vortex-based fuel premixing chamber featuring:
• Multiple Tangential Inlet Nozzles, distributed circumferentially along the outer periphery—separately delivering compressed air and hydrogen gas,
• A Tangential Outlet Port positioned on the periphery, aligned with the flow direction to discharge the mixed hydrogen-air stream toward the combustion disk,
• Flow direction indicators illustrating the clockwise or counter-clockwise swirl of gases inside the chamber.
Figure 3b (Radial Cross-Sectional View): The radial section demonstrates:
Top sectional view of the vortex pre-mixing and injection chamber. The diagram illustrates the angular positioning of inlet nozzles and outlet ports, guided vanes that direct swirling fuel mixture, and the optional tangential jet orientation to directly impart rotational impulse on piston surfaces.
Figure 4: Spiral Type Rotary Air Compressor Coil-
Figure 4(a): Front elevation view illustrating the spiral-type rotary air compressor coil concentrically mounted around the central shaft. The spiral geometry tapers from a large-radius intake zone to a narrow-radius outlet, enabling volumetric air compression through centrifugal rotation.
Figure 4(b): Side cross-sectional view showing the rotational interface assembly between the rotary air outlet union and the stationary fixed union. The fixed union is integrated with multiple tangentially oriented compressed air delivery ports that channel the airflow into preheating or fuel mixing chambers. The rotary-fixed coupling is supported by the engine body structure, ensuring sealed dynamic airflow transfer during shaft rotation.
List of parts/components
1. Combustion disk chamber
2. Oil sump
3. Piston
4. Heating coil/filament
5. Main shaft
6. Fuel/Air inlet valve/nozzle
7. Exhaust valve
8. Piston ring with groove
9. Preheating disk chamber
10. Compressed air inlet valve/nozzle
11. Fuel supply port
12. Hydrogen inlet valve/nozzle
13. Spiral Air compressor coil
14. Compressor air inlet port
15. Supply channel
16. Rotary union
17. Fixed union
18. Tangential outlet
19. Fixed mounting
20. Fuel supply pipe
21. Air supply pipe
22. Air filter
23. Air supply channel
WORKING CYCLE
1. Ambient air is captured by the spiral coil and compressed during rotation
2. Compressed air flows via rotary-fixed union into tangential injectors
3. Air enters into the heated vortex mixing chamber and forms a swirl
4. Hydrogen is tangentially injected and mixes with swirling air
5. The pre-mixed, high-pressure fuel enters the combustion disk tangentially
6. Combustion occurs in presence of electrically heated coil in Quadrants 1-2-3, pushing pistons along annular cam track and generating rotational force
7. Pistons apply torque to shaft via integrated crank linkage
8. In Quadrant 4, a continuously open exhaust port maintains a low-pressure zone that accelerates combustion gases and reinforces shaft rotation
WORKING DESCRIPTION
1. Air Induction and Compression: Ambient air is drawn in through a circumferential air filter integrated along the outer casing. The air is captured by a spiral, pressure horn-shaped air coil (13) that rotates coaxially with the central shaft as shown in figure 4a. Owing to its variable cross-sectional geometry—broad at the outer periphery and narrowing toward the shaft axis—the coil induces volumetric compression of the intake air as it progresses inward. The resulting high-pressure air is transferred into the engine body via a rotary union mechanism (16), which interfaces with a stationary air distribution manifold (17) & (18) rigidly mounted to the engine housing (19) as shown in figure 4b.
2. Vortex-Based Fuel Mixing: The compressed air enters a centrally positioned vortex pre-mixing disk chamber through three or more tangential nozzles (10) placed around its circumference as given in figure 3a. Simultaneously, hydrogen is injected tangentially (12) via ports integrated into the shaft’s periphery (not axially). The guided vanes inside the chamber create a controlled, tornado-like swirl, ensuring rapid and homogeneous mixing of air and hydrogen. The mixing direction and turbulence are optimized by the chamber geometry and vane orientation as shown in figure 3b.
3. Tangential Fuel Injection (continues type): The pre-mixed high-pressure fuel-air mixture is expelled tangentially (11) from the vortex chamber through curved outlet ducts. These ducts (20) direct the mixture into the fuel intake quadrants through fuel injection nozzle (6) of the annular combustion disks. The injection is timed and targeted such that the tangential momentum of the mixture imparts an impulse force directly onto the curved piston (3) surface, providing rotational thrust in addition to thermodynamic expansion.
4. Quadrant-Based Combustion Cycle: The engine supports two distinct quadrant-based operating modes—four-quadrant (single-cycle) and eight-quadrant (dual-cycle) configurations—based on how the annular combustion disk is segmented.
Four-Quadrant Operation (Single-Cycle Mode): As shown in figure 2a, the combustion disk is divided into four equal 90° segments. A single complete four-stroke cycle is executed over one full 360° revolution of the disk. Circular heating coil covers 1-3 quadrant. The operational phases are as follows:
• First Quadrant: Injection of the hydrogen-air fuel mixture.
• Second and Third Quadrants: Combustion and expansion of the working fluid, generating torque.
• Fourth Quadrant: Exhaust of combustion gases.
This mode ensures one power stroke per rotation per combustion segment, suitable for controlled single-pulse energy delivery.
Eight-Quadrant Operation (Dual-Cycle Mode): As shown in figure 2b, the disk is divided into eight 45° segments, enabling two full four-stroke cycles within each 360° revolution. In figure 2b, each combustion cycle is executed over a 180° segment, effectively doubling the number of power strokes per revolution compared to the four-quadrant mode. Heating coil (4) arrangement made in 1-3 quadrant and similarly in 5-7 quadrant as shown in figure 2b. This configuration increases power density and smoothens torque output, making it ideal for high-speed applications.
These operational modes offer flexibility in tuning the engine for either high-efficiency or high-power-density performance, depending on the application requirements.
5. Continuous Tangential Combustion and Pressure Gradient-Based Expansion
The engine employs a continuous tangential fuel-air injection strategy for generating rotational impulse across multiple quadrants of the annular combustion chamber. This design achieves stable, high-efficiency operation under the following key principles:
1. Internal Circular heating Coil with Distributed Combustion Zones
• An internally grooved circular heating coil (4) is embedded along the side wall of each annular combustion disk.
• The heating coil offers a continuous combustion of fuel mixture in 1,2 and 3 quadrant operation.
• This fuel delivery occurs continuously across:
o Quadrant 1 – Injection begins
o Quadrant 2 – Peak combustion zone
o Quadrant 3 – Continued expansion and residual burning
• Quadrant 4: Fuel injection is optionally reduced or paused to prepare for exhaust.
Benefits:
• Allows extended residence time for fuel combustion
• Supports slow, complete hydrogen burn for thermal efficiency
• Enables spatially distributed pressure rise, promoting smooth torque delivery
2. Secondary Tangential Fresh Air Inlet in Quadrant 2 & 3
• A dedicated tangential air nozzle (6’) introduces compressed fresh air into Quadrant 2 & 3.
• This jet performs dual roles:
o Enhances combustion by supplying surplus oxygen
o Applies tangential thrust, reinforcing shaft torque
Combustion + Impulse Hybridization:
• The combination of combustion pressure and fresh air momentum generates a compound tangential impulse on the piston (3).
• Particularly beneficial when piston movement is synchronized with expansion phase in Quadrant 2–3
3. Open Exhaust Port in Quadrant 4 with Pressure Gradient Advantage
• A permanently open exhaust port (7) is placed in Quadrant 4 to:
o Maintain near-atmospheric pressure
o Enable unimpeded outflow of exhaust gases
• This creates a strong pressure gradient across the chamber:
o Quadrants 1–3: High pressure and temperature
o Quadrant 4: Low pressure zone (open exhaust)
Resulting Phenomena:
• Promotes directional expansion flow of gases
• Gas naturally accelerates from high to low-pressure zones, enhancing piston movement
• Enables stable chamber thermodynamics and minimizes thermal shock
6. Piston Motion and Torque Generation: Inside each combustion disk, oval or round pistons (3) move along grooved angular channels (1) (technically termed annular guide tracks). The pistons are connected to the central shaft (5) via crank assemblies and are sized (~10 mm width) to minimize obstruction. The combined effect of combustion pressure and tangential jet impulse results in a smooth, continuous rotational motion of the shaft — much like a fluidic impulse turbine fused with a rotary IC engine.
7. Exhaust and Regenerative Heating: Burnt gases exit through dedicated valve ports aligned with exhaust quadrants. The fuel mixing chamber (9) shares a common wall with the adjacent combustion chamber (1), allowing the fuel-air mixture within to absorb radiative heat through thermal conduction and radiation from the combustion side, thereby elevating the temperature of the mixture prior to injection.
8. Lubrication and Heat Management: A partitioned oil sump (2) is housed in the lower engine casing. Micro-channels (~2 mm) route oil upward to the piston rings (8) for lubrication. Since the main shaft (5) rotates without an oil bath, it stays cleaner and operates at higher thermal margins. The design allows optional high-temp dry lubrication coatings (e.g., MoS₂).
ADVANTAGES OF THE INVENTION
1. High Thermal Efficiency: Vortex-based hydrogen-air pre-mixing and regenerative heating from adjacent chambers contribute to thermal efficiency exceeding 50%.
2. Tangential Injection System: All fuel and air injections are tangential, eliminating axial losses and enhancing swirl, mixing quality, and combustion speed.
3. Quadrant-Based Continuous Torque: The unique 4- or 8-quadrant combustion system ensures uninterrupted torque generation per 360° rotation, improving power consistency.
4. Integrated Spiral Air Compression: A rotating, spiral-shaped air coil performs dynamic air compression, reducing auxiliary compressor needs and improving system compactness.
5. Self-Reinforcing Pressure Gradient: A continuously open exhaust in the fourth quadrant establishes a sustained pressure differential, boosting rotational motion through directed gas flow.
6. Compact and Modular Design: The annular multi-disk configuration allows scalable implementation for various power classes with minimal space requirements.
7. Low Friction and Reliable Lubrication: Micro-lubrication channels and optional high-temperature coatings reduce wear and extend operational life without oil bath complexity.
8. Combustion Chamber Preheating: Heat radiated into the mixing chamber enhances hydrogen-air mixing and ignition readiness, optimizing fuel utilization.
9. Clean Hydrogen Propulsion: 100% hydrogen-based operation supports zero-emission mobility and aligns with global decarbonization goals.
Industrial Applicability: This invention supports clean propulsion in electric-hydrogen hybrid vehicles, decentralized power units, aerospace auxiliary drives, and green infrastructure systems. The modular annular structure allows scalable, compact, and efficient deployment.
Scalability: The engine architecture supports seamless scalability due to its modular annular disk design and centralized shaft system. By increasing the number of combustion disks, expanding the diameter of the annular chamber, or increase the quadrants, the system can be scaled from small sub-10 kW auxiliary units to high-power 100+ kW industrial or vehicular engines. The quadrant-based combustion mechanism allows flexible tuning of torque and efficiency, while the vortex fuel mixing chamber and regenerative compressor coil maintain performance consistency across sizes. Compact form factor and tangential-only injection design simplify thermal insulation and component integration in stacked or tandem configurations. This scalability makes the engine suitable for diverse platforms ranging from drones and two-wheelers to commercial trucks, locomotives, and stationary generators.
, Claims:Claim 1: A rotary internal combustion engine powered by hydrogen comprising a single annular rotating disk, the disk defining a continuous circular chamber sequentially divided into a tangential air compression section, a fuel mixing section, and a combustion-expansion section, all operating in a quadrant-based rotational cycle
Claim 2: The engine of claim 1, wherein all air and hydrogen injections are performed tangentially, and a central vortex-based mixing chamber is provided adjacent to the combustion disks, the chamber receiving compressed air through tangential injector channels and hydrogen through circumferential tangential ports near the shaft region, forming a swirling pre-mixed hydrogen-air stream.
Claim 3: The engine of claim 1, wherein the combustion section is equipped with circumferential grooves forming curved piston paths, and the combustion force acts tangentially on pistons housed within said grooves to produce torque on the central shaft.
Claim 4: The engine of claim 1, wherein compressed air is generated by a spiral-shaped rotating air coil mounted on the central shaft, the coil having a variable cross-sectional area that reduces in volume toward the shaft, thereby compressing ambient air as it spirals inward, and wherein the inner end of the coil is connected to a stationary air distribution assembly via a rotary and fixed union interface.
Claim 5: The engine of claim 1, wherein quadrant-based combustion is continuously sustained, with dedicated quadrants for injection, expansion, and exhaust, and a continuously open tangential exhaust port located in the final quadrant to maintain pressure differential.
Claim 6: The engine of claim 1, wherein the annular combustion disk is configured for quadrant-based rotational cycles, including: (a) a four-quadrant mode in which each 90-degree sector completes a single four-stroke combustion cycle over 360 degrees of disk rotation, and (b) an eight-quadrant mode in which two four-stroke combustion cycles are completed within a single 360-degree rotation using 45-degree sectors.
Claim 7: The engine of claim 1, wherein the piston grooves are angularly bent to match the tangential motion of the combustion gases, and the pistons are configured with a minimal radial contact width to reduce flow obstruction and maintain dynamic sealing.
Claim 8: The engine of claim 1, wherein a dedicated internal oil sump is integrated into the engine housing, and micro-channels of approximately 2 mm diameter are configured to deliver lubricant from the sump to piston rings, enabling continuous lubrication without a traditional oil bath.
Claim 9: The engine of claim 1, wherein combustion occurs primarily in Quadrants 1–3, and a continuously open tangential exhaust port is positioned in Quadrant 4 to establish a pressure gradient that accelerates combustion gases toward the exhaust side, reinforcing tangential torque on the linked pistons.
Claim 10: The engine of claim 1, further comprising an auxiliary tangential nozzle that delivers compressed fresh air into the second and third quadrant to simultaneously sustain combustion and enhance rotational impulse via pressure dynamics.
Claim 11: The engine of claim 1, wherein the system produces rotational thrust via three mechanisms: (a) thermodynamic expansion from combustion, (b) tangential momentum of fuel mixture injection, and (c) high-pressure to low-pressure gas migration induced by quadrant-specific exhaust pressure differential.
Claim 12: The engine of claim 1, wherein the rotary annular disk combustion chamber includes a thermally exposed internal circular heating coil installed on adjacent wall, configured to ignite the hydrogen-air mixture or pre-burn the fuel mixture before its entry into the combustion quadrants, thereby ensuring complete fuel combustion and enhanced thermal efficiency.