Passive Fuselage Temperature Sensor Using Pressure Gradient
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing temperature sensing devices in aircraft require a powered fan to draw cabin air into an air duct, adding complexity and increasing noise, cost, and the risk of suboptimal performance.
Innovation Solution
A temperature sensing device that uses airflow from the environmental control system to passively draw cabin air across a temperature sensor via a duct with strategically designed nozzles and barrels, creating a pressure difference to eliminate the need for a fan, thereby reducing noise and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a powered fan is used to draw cabin air into an air duct, then air can be drawn into the duct, but device complexity increases and noise increases
Solution Approach 1:
The patent removes the powered fan from the system entirely, extracting the problematic component that caused complexity and noise. Instead, it uses the existing environmental control system airflow to create a pressure difference that passively draws cabin air through the duct, achieving the same function without the fan.
Solution Approach 2:
The patent replaces the mechanical fan-driven air intake system with a pressure-difference-driven passive system. The mechanical energy from a fan is substituted with a pneumatic pressure gradient created by the environmental control system's airflow, eliminating moving parts and reducing complexity.
2Ease of operation
If a powered fan is used to draw cabin air into an air duct, then air can be drawn into the duct, but noise increases
Solution Approach 1:
The patent removes the powered fan from the system entirely, extracting the noise-generating component. The passive pressure-difference system operates silently compared to a mechanical fan, eliminating the harmful noise factor while maintaining air drawing capability.
3Ease of operation
If a powered fan is used to draw cabin air into an air duct, then air can be drawn into the duct, but additional components are required
Solution Approach 1:
The patent merges the air drawing function with the existing environmental control system airflow. Instead of adding a separate fan system, it integrates the temperature sensing function into the airflow path of the environmental control system, reducing the total number of components.
Solution Approach 2:
The duct system serves multiple functions: it is part of the environmental control system airflow path and simultaneously serves as the air intake pathway for the temperature sensor. This multi-functionality eliminates the need for separate dedicated air intake components.
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 solution effectively measures cabin temperature without a fan, reducing noise, cost, and the risk of suboptimal performance, while maintaining accurate temperature sensing, and is suitable for use in aircraft and other applications.
Implementation Method 1
the secondary air is passively drawn into the cabin air inlet and to the duct due to a pressure difference present in the duct
Data Source
AI summary
An example temperature sensing device includes an air distribution inlet through which primary air is blown into via an environmental control system, a cabin air inlet through which secondary air enters from a passenger area of a fuselage and the cabin air inlet is coupled to the air distribution inlet through a duct and the secondary air is passively drawn into the cabin air inlet and to the duct due to a pressure difference present in the duct, and a temperature sensor coupled to the duct and positioned downstream of the cabin air inlet along an airflow path of the secondary air so as to be exposed to the secondary air drawn in through the cabin air inlet and flowing through the duct.