Aspirator Nozzle Offset Reduces Gas Pressure Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional aspirators for inflating evacuation devices in vehicles, such as aircraft, require larger compressed gas sources due to inefficiencies in nozzle arrangements, leading to increased size and weight, and higher pressure drops, which limit the ability to deploy evacuation assemblies effectively.
Innovation Solution
The aspirator design features a duct with a vane spanning the upstream portion, laterally offset nozzles, and a converging-diverging nozzle configuration, which reduces resistance to primary gas flow and minimizes the size of the compressed gas source required by limiting recirculation zones and pressure loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If conventional nozzle arrangements are used in aspirators, then the evacuation assembly can be inflated, but the compressed gas source size and weight increase
Solution Approach 1:
The patent changes the geometric parameters of the nozzle arrangement by laterally offsetting the nozzle from the flow axis and axially overlapping it with the vane, which modifies the flow characteristics to reduce recirculation zones and pressure loss, thereby reducing the required compressed gas source size while maintaining inflation effectiveness
Solution Approach 2:
The patent moves the nozzle from a conventional axial position to a lateral offset position relative to the flow axis, utilizing a different spatial dimension to optimize flow patterns and reduce the size of the compressed gas source required
2Productivity
If conventional nozzle arrangements with turns in the conduit are used, then gas flow can be directed to the nozzle, but aspirator efficiency decreases
Solution Approach 1:
The patent extracts and eliminates the turns in the conduit from the gas flow path, creating a more direct flow path from the compressed gas source to the nozzle, which reduces pressure loss and improves aspirator efficiency while simplifying the overall device configuration
3Productivity
If larger compressed gas sources are used to compensate for aspirator inefficiency, then inflation requirement can be met, but assembly size and weight increase
Solution Approach 1:
By changing the nozzle position parameters (lateral offset and axial overlap with vane), the patent optimizes the aspirator's gas combining efficiency, allowing a smaller compressed gas source to provide the required inflation capability while reducing overall assembly volume
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 design allows for efficient inflation of evacuation devices with a smaller compressed gas source, reducing the size and weight of the assembly while maintaining effective deployment capabilities.
Implementation Method 1
When triggered in an inflatable evacuation assembly a flow of gas from the pressurized gas source is provided to the nozzle to accelerate fluid ingested from the ambient environment through the duct using the Venturi effect
Data Source
AI summary
An aspirator for an evacuation assembly includes a duct defining a flow axis with an upstream portion and a downstream portion, a vane spanning the upstream portion of the duct, and a nozzle. The nozzle has an outlet, is supported by the vane, and is positioned within the upstream portion of the duct. The outlet is laterally offset from the flow axis and is axially overlapped by the vane to limit resistance to a primary gas flow entering the duct through the outlet of the nozzle. Evacuation assemblies are also described.