Variable-Transmission Blower Compressor for Aircraft Pressurization
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Solution Overview
Problem
Existing aircraft cabin pressurization systems that use engine bleed air from a gas turbine engine reduce its efficiency and increase fuel consumption.
Innovation Solution
A blower system with a variable transmission and electrical machines that utilize air from a lower pressure source, such as a bypass duct, to compress air independently of the gas turbine engine's rotational speed, allowing for controlled air delivery to the aircraft cabin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If engine bleed air is used for cabin pressurization, then the air supply is readily available from the gas turbine engine, but the engine efficiency is reduced and fuel consumption increases
Solution Approach 1:
The system separates the cabin pressurization function from the gas turbine engine by using an independent blower assembly with its own compressor and electrical motor, allowing the engine to operate independently for propulsion while the blower handles pressurization needs
Solution Approach 2:
The blower assembly serves multiple functions: it pressurizes cabin air, can provide air for air conditioning systems, and can potentially supply air for other aircraft systems, replacing multiple dedicated systems with a single multi-functional unit
2Device complexity
If a fixed ratio transmission is used to drive the blower compressor, then the system is simpler, but the air delivery speed cannot be independently controlled from the gas turbine rotational speed
Solution Approach 1:
The system uses a variable ratio transmission mechanism that allows the rotational speed ratio between the gas turbine and blower compressor to be dynamically adjusted, enabling independent control of air delivery speed while maintaining mechanical coupling
Solution Approach 2:
A variable ratio transmission mechanism acts as an intermediary between the gas turbine engine and the blower compressor, allowing speed decoupling while maintaining mechanical connection, thus providing control flexibility without requiring a fully independent electrical system
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
Improves aircraft cabin pressurization efficiency by reducing fuel consumption and enhancing the flexibility of air supply to the aircraft's airframe systems.
Implementation Method 1
first and second electrical machines, each comprising an electric rotor and an electric stator
Implementation Method 2
a blower compressor in fluid communication with the air inlet and the air outlet, the blower compressor comprising a first rotor and a second rotor, wherein the first and second rotors are independently rotatable in order to compress air received from the air inlet and deliver the compressed air to the air outlet
Data Source
AI summary
A blower system for supplying pressurized air to an airframe of an aircraft comprises: an air inlet for receiving air from an air source; an air outlet for supplying pressurized air to an airframe; a blower compressor in fluid communication with the air inlet and the air outlet, the blower compressor comprising a first rotor and a second rotor, wherein the first and second rotors are independently rotatable in order to compress air received from the air inlet and deliver the compressed air to the air outlet; a variable transmission comprising a first output for driving the first rotor, a second output for driving the second rotor, and first, second and third inputs; and first and second electrical machines, each comprising an electric rotor and an electric stator, wherein: the first input of the variable transmission is configured to be mechanically coupled to a spool of a gas turbine engine; the second input of the transmission is mechanically coupled to the electric rotor of the first electrical machine; the third input of the transmission is mechanically coupled to the electric rotor of the second electrical machine; and the electric stators of the first and second electrical machines are electrically connected to an electrical power management system configured to control the supply of electrical power to the first and second electrical machines in order to control the speed of the first and second outputs of the variable transmission.