Micro-Auxiliary Power Unit Thermal Event Suppression
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Solution Overview
Problem
Small aircraft lack a reliable and efficient power source when main engines are not operating, as traditional auxiliary power units are bulky, heavy, and batteries provide limited and unreliable power, while external ground-based power may not be available.
Innovation Solution
A micro-auxiliary power unit featuring a Wankel engine within a thermal resistant enclosure, equipped with a starter-generator, detection and suppression system, cooling system, lubrication system, and mounting structure, capable of generating electric power and safely managing thermal events, is designed for integration with small aircraft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional auxiliary power units are used, then power supply capability is improved, but weight and device complexity increase
Solution Approach 1:
The power unit is segmented into modular components (engine module, generator module, control module) that can be independently designed and optimized. This allows the system to achieve high power output while keeping individual component weights manageable and enabling selective installation based on specific aircraft needs.
Solution Approach 2:
The patent replaces traditional mechanical auxiliary power unit components with a compact engine design that directly couples to the generator, eliminating complex mechanical transmission systems. This substitution reduces overall weight while maintaining power supply capability.
2Power
If traditional auxiliary power units are used, then power supply capability is improved, but device complexity increases
Solution Approach 1:
The patent merges the engine, generator, and control systems into an integrated auxiliary power unit. This consolidation reduces device complexity by eliminating the need for separate installations and interconnections of multiple independent systems, while maintaining full power supply capability.
Solution Approach 2:
The auxiliary power unit is designed with universal applicability across different aircraft types and configurations. The standardized interface and modular design allow the same power unit to serve multiple functions and be installed in various aircraft without requiring complex customizations.
3Device complexity
If batteries are used, then device complexity is reduced, but power output and reliability deteriorate
Solution Approach 1:
The auxiliary power unit is designed to be self-sufficient with integrated fuel storage, engine operation, and power generation capabilities. This self-service design eliminates the need for external power sources while providing reliable high-power output, contrasting with battery systems that require external charging infrastructure.
4Reliability
If thermal containment measures are implemented, then safety is improved, but device complexity increases
Solution Approach 1:
The thermal containment system is nested within the existing auxiliary power unit structure, with fire detection and suppression systems integrated into the engine compartment and fuel storage areas. This nested approach improves safety without adding significant external complexity, as the containment measures are incorporated into the core design rather than added as separate systems.
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
The micro-auxiliary power unit provides reliable electric power to small aircraft, reduces battery requirements, and ensures safe operation by containing and extinguishing thermal events, offering a compact, efficient, and reliable alternative to traditional power sources.
Implementation Method 1
The engine is configured to combust the air and the fuel to drive an output shaft
Implementation Method 2
The starter-generator is configured to generate electric power for the vehicle based on the rotation of the output shaft
Implementation Method 3
The detection and suppression system has at least one sensor disposed within the enclosure that observes a condition of the enclosure and generates sensor signals based thereon
Implementation Method 4
Based on the determination of the presence of the thermal event, the processor is further configured to output one or more control signals to a suppressant valve to supply a suppressant agent into the enclosure to extinguish the thermal event
Implementation Method 5
The cooling system includes a cooling fan coupled to the output shaft, a coolant pump for circulating coolant fluid and a radiator
Implementation Method 6
a fuel valve fluidly coupled to the fuel line upstream from the enclosure, and the fuel valve is movable between a first, opened position in which fuel flows through the fuel line and a second, closed position in which the flow of fuel is inhibited
Data Source
AI summary
A micro-auxiliary power unit for supplying electric power to a vehicle includes a thermal resistant enclosure having an intake duct for receiving air, and a source of fuel. A fuel valve is fluidly coupled from the enclosure, and the fuel valve is movable between an opened position and a closed position. The micro-auxiliary power unit includes a Wankel engine to drive an output shaft and a starter-generator coupled to the output shaft to generate electric power. The micro-auxiliary power unit includes a system that has at least one sensor disposed within the enclosure that observes a condition of the enclosure and generates sensor signals, and a controller having a processor that receives the sensor signals, determines the presence of a thermal event within the enclosure and based on the determination, outputs one or more control signals to the fuel valve to move the fuel valve to the closed position.