Aircraft Air Cycle Machine Layout for Straight Turbine Bypass Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional air cycle machines in environmental control systems for aircraft suffer from inefficiencies due to complex interactions between air and liquid subsystems, leading to wasted thermal energy and reduced system efficiency, particularly because the fan rotor is located on one end of the machine, affecting the entire system's performance.
Innovation Solution
The compressor is positioned on a common shaft between two turbines, with the turbines located outboard, reducing circuitousness of bypass circuits and enhancing efficiency, and integral valve ports are integrated into the ACM housing for weight reduction and simplified installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the fan rotor is located on one end of the ACM, then the installation is simplified, but the turbine efficiency and overall system performance are reduced
Solution Approach 1:
The patent inverts the conventional ACM layout by positioning the compressor between the two turbines rather than having the fan on one end. This reversal of the traditional configuration allows both turbines to be located outboard on opposite ends of the compressor, enabling straight axial outlet diffusers and eliminating circuitous bypass flows, thereby achieving up to 90% turbine efficiency while maintaining installation simplicity through the symmetric outboard positioning of rotating components.
2Device complexity
If the compressor is located on one end of the ACM with turbines on the same side, then the structure is simplified, but the bypass circuits become circuitous and less efficient
Solution Approach 1:
The patent inverts the conventional single-side turbine arrangement by placing turbines on opposite outboard ends of the compressor. This inversion creates symmetric, direct airflow paths for bypass circuits, eliminating the circuitous routes found in conventional designs and significantly reducing energy losses while maintaining structural simplicity through the balanced symmetric layout.
3Adaptability or versatility
If conventional ACM components are used with separate mounting, then the design is flexible, but the system weight is increased
Solution Approach 1:
The patent merges the valve ports directly into the ACM housing structure rather than using separate mounted components. This integration eliminates the need for additional mounting hardware and reduces the overall component count, achieving weight reduction while maintaining design flexibility through the modular housing design that incorporates the valve ports as integral features.
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 configuration achieves the highest efficiency with straight axial outlet diffusers, resulting in better performance and lower system weight, with turbine efficiencies reaching up to 90% and improved airflow management.
Implementation Method 1
Expanded air from the turbine flows through another water collector and into a liquid-to-air heat exchanger
Implementation Method 2
The bleed air is pre-cooled within an air-to-air heat exchanger with heat being rejected to RAM air
Implementation Method 3
Condensed water vapor is extracted by a water extractor
Data Source
AI summary
An ECS system provides an ACM which locates the compressor upon a common shaft between a first turbine and a second turbine. Each RAF is located remote from the ACM such that the turbines are located outboard on each end of the ACM to provide the highest efficiency possible with each turbine using a straight axial outlet diffuser. As the compressor is located between the turbines the bypass circuits from the turbines are less circuitous and more efficient. Integral valve ports formed into the ACM housing portions results in a weight reduced design due to increase bypass efficiencies and simplified installations.