Ram-Air Duct Auxiliary Air Mover for Aircraft Cooling
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Solution Overview
Problem
Existing ram-air duct systems for aircraft rely on bleeding high pressure air from gas turbine engines, which reduces engine efficiency and increases fuel consumption.
Innovation Solution
A ram-air duct system that includes an auxiliary air passageway and an electrically-driven air mover to introduce auxiliary air into the duct, enhancing airflow and heat exchange without relying on high pressure air bleeding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high pressure air is bled from the gas turbine engine core, then the flow of air through the ram-air duct is augmented, but the engine efficiency is reduced and fuel consumption increases
Solution Approach 1:
The invention extracts the air moving function from the gas turbine engine core by using a separate electrically-driven air mover (fan or compressor) to drive airflow through the ram-air duct. This separation allows the engine core to operate independently without bleeding high pressure air, thereby maintaining engine efficiency while still achieving the required airflow for heat exchange.
Solution Approach 2:
The air mover is designed to perform multiple functions: it can drive airflow through the ram-air duct for heat exchange, and can also supply pressurized air to the airframe pressurization system. This multi-functionality reduces the need for separate systems and improves overall system efficiency.
2Productivity
If high pressure air is bled from the gas turbine engine core, then the flow of air through the ram-air duct is augmented, but the engine efficiency is reduced
Solution Approach 1:
The air moving function is extracted from the engine core and assigned to a dedicated electrically-driven air mover. This ensures that the engine core operates at optimal efficiency without the performance penalty of bleeding high pressure air, while still achieving the required airflow through the ram-air duct for effective heat exchange.
3Loss of energy
If an electrically-driven air mover is used to drive airflow through the ram-air duct, then fuel consumption is reduced, but the device complexity increases
Solution Approach 1:
The air mover is designed as a multi-functional component that can serve both the ram-air duct system and the airframe pressurization system. By consolidating these functions into a single device, the overall system complexity is minimized while achieving energy efficiency improvements.
Solution Approach 2:
The invention merges the air moving function with the existing airframe pressurization system by allowing the air mover to supply pressurized air to both the ram-air duct and the airframe. This integration reduces the number of separate components and simplifies the overall system architecture.
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 augments and promotes the flow of ram-air, increasing the mass flow rate and enhancing convective heat exchange, thereby improving cooling efficiency while reducing fuel consumption and maintaining engine performance.
Implementation Method 1
a heat exchanger configured to exchange heat with air within the ram-air duct; The ram-air duct is configured to convey a flow of air therethrough for convective heat exchange with the heat exchanger
Implementation Method 2
The air mover may be configured to further compress air drawn from the airframe pressurisation system, for example to an elevated pressure higher than a pressure of air in the airframe pressurisation system
Implementation Method 3
discharge of the flow of auxiliary air into the ram-air duct: augments the flow of ram-air by increasing a total mass flow rate of air through the ram-air duct; and/or promotes an increased mass flow rate of the flow of ram-air
Data Source
AI summary
A ram-air duct system includes a ram-air duct configured to receive a flow of ram-air from a ram-air inlet and discharge the flow to a ram-air outlet. The system also includes a heat exchanger configured to exchange heat with air within the ram-air duct, an auxiliary air passageway and an electrically-driven air mover configured to move a flow of auxiliary air along the auxiliary air passageway for discharge into the ram-air duct through an intermediate inlet between the ram-air inlet and the ram-air outlet. The air duct system further includes a controller configured to selectively operate the ram-air duct system in an auxiliary supply mode in which the air mover and/or a control valve are controlled to cause the flow of auxiliary air to be discharged into the duct through the intermediate inlet, to thereby control a rate of heat exchange between the heat exchanger and air within the duct.