Ammonia-Based Propulsion System for Combined Cycle Engines
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Solution Overview
Problem
Current combined propulsion systems for high Mach number aircraft require separate fuel sources for gas turbine and ramjet engines, leading to inefficiencies and complexity, as they often shut down the gas turbine engine when the ramjet engine is operational, and use different fuels for each engine.
Innovation Solution
A propulsion system that utilizes an ammonia-based fuel, which is heated to separate hydrogen and nitrogen components, allowing both engines to operate using a single fuel source by providing hydrogen for combustion and nitrogen for cooling and other purposes, eliminating the need for separate fuel tanks and enabling continuous operation across a wide speed range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate fuel sources are used for gas turbine and ramjet engines, then each engine can be optimized for its specific fuel type, but the system complexity and fuel storage requirements increase
Solution Approach 1:
The patent merges the fuel storage system by using a single ammonia-based fuel for both gas turbine and ramjet engines, eliminating the need for separate fuel tanks and fuel delivery systems. The ammonia fuel serves dual purposes: as combustion fuel for the gas turbine and as a source of hydrogen for the ramjet engine after thermal decomposition.
Solution Approach 2:
The ammonia-based fuel system provides multi-functionality by serving as both the primary fuel for the gas turbine engine and the source material for hydrogen production for the ramjet engine. This universal fuel system replaces what would traditionally require separate petroleum-based and hydrogen fuel systems.
2Speed
If the gas turbine engine is shut down when the ramjet engine is operational, then the aircraft can achieve high Mach number operation, but continuous operation across all speed ranges is lost
Solution Approach 1:
The patent enables continuous operation of both gas turbine and ramjet engines simultaneously by providing the ramjet engine with hydrogen derived from thermal decomposition of ammonia in the gas turbine's combustion system. This eliminates the need to shut down the gas turbine when transitioning to high-speed ramjet operation, allowing continuous thrust across the entire speed range.
3Use of energy by moving object
If different fuel types are used for gas turbine and ramjet engines, then each engine can operate at optimal efficiency, but the number of fuel storage tanks and fuel delivery systems increases
Solution Approach 1:
The patent combines multiple fuel storage requirements into a single ammonia-based fuel system. The ammonia serves as the primary fuel for the gas turbine and simultaneously as the source of hydrogen for the ramjet engine through thermal decomposition, eliminating the need for separate petroleum-based fuel tanks and hydrogen storage tanks.
Solution Approach 2:
The patent utilizes parameter changes by thermally decomposing ammonia (changing its chemical state) to produce hydrogen and nitrogen gases. This parameter change allows the same ammonia-based fuel to serve dual purposes: direct combustion in the gas turbine and hydrogen supply for the ramjet engine, reducing overall fuel storage requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows both the turbine and ramjet engines to operate simultaneously with a single fuel source, enhancing efficiency and reducing complexity by enabling continuous operation from low to high speeds without the need for separate fuel types, thereby improving propulsion system performance and reducing fuel storage requirements.
Implementation Method 1
a heat exchanger in which the ammonia-based fuel is heated to separate a first fuel component, which is gaseous or supercritical hydrogen, from the ammonia-based fuel, and a second fuel component, which is gaseous or supercritical nitrogen, from the ammonia-based fuel
Implementation Method 2
a separator that separates the gaseous fuel components into a first fuel component and a second fuel component
Data Source
AI summary
A propulsion system includes a turbine engine, and a ramjet engine arranged in parallel with the turbine engine, a fuel storage tank that stores a fuel, such as an ammonia-based fuel, a heat exchanger through which the fuel passes to obtain gaseous (or supercritical) fuel components of the fuel, and a separator that separates the gaseous fuel components into a first fuel component and a second fuel component. The first fuel component is provided to the ramjet engine for ramjet combustion and/or to the turbine engine for turbine combustion, in a high speed operating state of the propulsion system, while the second fuel component may be provided to an inlet of the turbine engine for the turbine combustion.