Aircraft Blower Transmission for Bleedless Cabin Pressurization
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Solution Overview
Problem
Bleeding high-pressure air from a gas turbine engine for aircraft cabin pressurization reduces engine efficiency and increases fuel consumption.
Innovation Solution
A blower system with independently rotatable first and second rotors, driven by a variable transmission and electrical machines, which utilizes air from a lower pressure source in the gas turbine engine, allowing independent speed control and reducing dependency on engine speed for air pressurization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high pressure air is bled from the gas turbine engine compressor section for cabin pressurization, then the air pressurization system can supply pressurized air to the cabin, but the engine efficiency is reduced and fuel consumption increases
Solution Approach 1:
The patent extracts the air pressurization function from the gas turbine engine core by using a separate blower system that draws air from the bypass duct instead of bleeding air from the compressor section. This separates the pressurization function from the propulsion function, allowing the engine to operate at peak efficiency while the blower independently provides cabin pressurization air.
Solution Approach 2:
The blower system acts as an intermediary device between the bypass air source and the cabin pressurization system. It takes lower pressure bypass air and compresses it to the required cabin pressure, mediating the pressure difference without requiring high-pressure bleed air from the engine core.
2Loss of energy
If a blower system uses air from a lower pressure source such as bypass duct, then engine efficiency is improved, but additional compression equipment is required
Solution Approach 1:
The blower system employs a variable transmission mechanism that allows dynamic adjustment of the rotor speeds independently of the engine speed. This enables the compression ratio and air flow to be optimized for different flight conditions, maintaining energy efficiency while adapting to varying cabin pressurization requirements.
Solution Approach 2:
The patent replaces traditional mechanical compression systems with an electrically-driven blower system controlled by a power management system. The electric motors provide precise control over compression parameters, substituting complex mechanical linkages with electrical control systems that are more efficient and easier to manage.
3Adaptability or versatility
If the blower system uses a variable transmission with independent rotor control, then speed control versatility is enhanced, but the transmission complexity increases
Solution Approach 1:
The variable transmission system is segmented into two independently controlled rotor systems, each with its own electric motor and control parameters. This segmentation allows each rotor to be optimized for specific functions (e.g., one for suction, one for delivery), providing versatility while keeping each subsystem relatively simple and manageable.
Solution Approach 2:
The blower system is designed with multi-functionality to handle various operating conditions - it can operate in different modes (e.g., ground operation, flight operation, different altitude conditions) by adjusting the independent rotor speeds. The same basic structure serves multiple functions across different flight regimes, reducing the need for multiple specialized 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
Improves aircraft cabin pressurization efficiency by decoupling rotor speeds from engine speed, thereby reducing fuel consumption and enhancing system versatility.
Implementation Method 1
a blower compressor (420) in fluid communication with the air inlet (422) and the air outlet (426), the blower compressor comprising a first rotor (420a) and a second rotor (420b), wherein the first and second rotors (420a, 420b) are independently rotatable in order to compress air received from the air inlet (422) and deliver the compressed air to the air outlet (426)
Implementation Method 2
first and second electrical machines (464, 465), each comprising an electric rotor and an electric stator
Implementation Method 3
a third electrical machine (462) comprising an electric rotor and an electric stator. The electric rotor of the third electrical machine (462) may be configured to be mechanically coupled to the spool (440) of the gas turbine engine (10), whereby the third electrical machine (462) is operable to generate electrical power from the spool (440) of the gas turbine engine (10)
Data Source
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AI summary
A blower system (400) for supplying pressurized air to an airframe of an aircraft comprises: an air inlet (422) for receiving air from an air source; an air outlet (426) for supplying pressurized air to an airframe; a blower compressor (420) in fluid communication with the air inlet and the air outlet, the blower compressor comprising a first rotor (420a) and a second rotor (420b), 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 (430) comprising a first output (436) for driving the first rotor, a second output (438) for driving the second rotor, and first, second and third inputs (432, 434, 435); and first and second electrical machines (464, 465), 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 (440) of a gas turbine engine (10); 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 (466) 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.