The complexity, cost, and material temperature limits of turbine hot-section hardware constrain modern aircraft propulsion. The Short-Stroke Valve (STV™) platform proposes a different architecture from conventional turbine engines. Modular high-boost internal-combustion units generate high-temperature, high-pressure gas that expands directly through a propulsive nozzle to produce thrust. By bypassing high-temperature turbine conversion, STV™ may reduce hot-section complexity and improve the direct conversion of gas energy into thrust.

At the cylinder level, short-stroke valves work with the fixed-cam gas-exchange system to retain basic gas exchange while adding precise, staged timing control of the gas path. Two independently controlled STV™ units manage staged intake and staged exhaust. Staged intake creates a three-layer cylinder charge: air, a low-oxygen fuel-rich mixture, and air. The middle layer supports stable combustion, while the surrounding air layers help control temperature, suppress knock, and reduce emissions. Staged exhaust divides blowdown into high-pressure and low-pressure phases. High-pressure exhaust supports turbocharging or exhaust gas recirculation (EGR) to recover pressure energy, while low-pressure exhaust flows directly into the exhaust pipe, reducing backpressure and pumping losses. Between 20° BTDC and 40° ATDC, a third STV™ port connects in-cylinder high-pressure gas to pressure-regulating chambers. Its timing and duration are adjusted according to peak combustion pressure, extending the high-boost range and reducing combustion noise.

This innovation integrates rapid gas-path control, low-oxygen stratified combustion, pressure-wave buffering, and staged exhaust energy management into one engine platform. The system is compatible with gasoline, natural gas, methanol, ammonia/hydrogen blends, jet fuel, and hydrogen. For large aircraft, multiple small high-boost STV™ units can operate in parallel: their mechanical output can drive the compressor and fan assembly, while their high-temperature, high-pressure gas enters a propulsive nozzle for secondary expansion and thrust generation. In this architecture, the propulsive nozzle handles secondary gas expansion and thrust production, eliminating the conventional high-temperature turbine as the core energy-conversion component. This combined-cycle approach could move beyond the approximately 1550 K turbine-material limit and raise maximum gas temperature toward the approximately 2550 K level of in-cylinder combustion.

Preliminary Carnot-cycle estimates suggest that, with jet fuel, this temperature increase could improve thermal efficiency by about 50% and reduce fuel consumption by roughly one third. With liquid hydrogen, the same temperature benefit, combined with cryogenic energy recovery and lower onboard fuel mass, could yield aircraft-level energy savings approaching 50%. These estimates require refinement through full-cycle simulation, aircraft integration analysis, and prototype testing.

The STV™ system has a practical engineering path. Cylinder-head modules can be cast or machined; key valve spools and components can use hardened materials, high-temperature seals, and heat-resistant coatings; and actuation can be electromagnetic or mechanical. Development should proceed in stages, validating valve durability, leakage, actuator response, single-cylinder combustion stability, high-boost multi-cylinder operation, and engine–nozzle integration. Applications include aircraft propulsion, ground and data-center power generation, heavy-duty engines, marine propulsion, and hydrogen-oriented low-carbon power systems. The lead applicant’s nearly forty years of engine research and patent work support future validation and engineering development.