Offset Gas Generator Layout for Twin Aircraft Propulsors
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Solution Overview
Problem
Small airplanes face challenges with propulsion systems that require inefficient engines due to limited compressor size and compression ratios, leading to suboptimal thrust and aerodynamic disadvantages.
Innovation Solution
A propulsion system with two rotating propulsive members and a single gas generator offset from the propulsive members, allowing larger gas generator dimensions for improved efficiency and thrust, connected via a transmission box and optionally an auxiliary turbomachine for redundancy and energy supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a single engine is directly fastened to the fuselage on top of the airplane, then a proportionally larger compressor can be placed in relation to fuselage dimensions, but the engine dimensions must offer good aerodynamic conditions which limits the solution to some types of airplanes
Solution Approach 1:
The propulsion system is divided into two independent rotating propulsive members (each with its own compressor and gas generator) positioned on either side of the fuselage, rather than a single centralized engine. This segmentation allows each unit to be smaller and more adaptable to different airplane types while collectively providing the necessary thrust.
Solution Approach 2:
The solution transitions from a vertical engine placement (on top of fuselage) to a lateral distribution (on either side of fuselage). This dimensional change in engine positioning allows for better aerodynamic integration and broader applicability to different airplane configurations while maintaining adequate compressor size.
2Force
If two turbine engines are positioned on either side of the main body, then thrust is generated effectively, but each engine has reduced dimensions leading to limited compression ratio and temperature
Solution Approach 1:
The patent merges the functions of two separate engines into a coordinated dual-propulsive-member system where each member operates independently but contributes to the same thrust objective. This allows optimization of each unit's dimensions and thermal characteristics while maintaining overall thrust effectiveness.
Solution Approach 2:
Each rotating propulsive member is designed with locally optimized characteristics including appropriate compressor size, compression ratio, and temperature parameters tailored to its specific position and function, rather than being constrained by centralized engine design limitations.
3Weight of moving object
If engine dimensions are reduced for small airplanes, then the engine fits the aircraft size, but the compressor size and compression ratio are limited reducing efficiency
Solution Approach 1:
The propulsion system uses two smaller rotating propulsive members positioned laterally, which can be scaled appropriately for small airplane weight constraints while collectively providing sufficient thrust and maintaining adequate compressor efficiency through optimized local design.
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 system provides enhanced thrust and efficiency by dissociating the gas generator from the propulsive members, reducing aerodynamic impact and enabling greater compression ratios, with optional redundancy for reliable operation.
Implementation Method 1
The gas generator comprises at least one compressor, configured to compress an incoming air stream so as to output air having high speed, pressure and temperature
Implementation Method 2
The gas generator further comprises a combustion chamber for combustion of a compressed air stream with fuel to generate a significant amount of energy
Implementation Method 3
The gas generator comprises at least one turbine configured to recover energy from the combustion chamber in order to drive the compressor and fan
Implementation Method 4
a turbojet engine is configured to produce an acceleration of the air between inlet and outlet of the turbojet engine
Data Source
AI summary
The invention relates to a propulsion system intended to be mounted on an aircraft comprising a main body, said propulsion system comprising: —a first rotating propulsive member and a second rotating propulsive member that are intended to be mounted on either side of said main body, —a transmission housing connected to the first rotating propulsive member via a first mechanical shaft and to the second rotating propulsive member via a second mechanical shaft, —a single gas generator connected to said transmission housing and configured to rotate the first rotating propulsive member and the second rotating propulsive member, and—a single auxiliary turbomachine configured to rotate the first rotating propulsive member and the second rotating propulsive member independently of the gas generator.