Supersonic Speed Attenuator De-icing via Segmented Cavity
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Solution Overview
Problem
The existing defrosting methods for supersonic speed attenuators in aircraft propulsion assemblies are inefficient, as they either require increasing the defrosting air flow rate or temperature, leading to a loss of turbomachine performance, or fail to effectively prevent frost formation on the conical outer wall.
Innovation Solution
A calibrated defrosting device with an internal wall in the cavity of the supersonic speed attenuator that restricts the defrosting air flow to a specific volume, allowing targeted heat exchange with the conical external wall, maintaining the air flow speed and avoiding energy expenditure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the defrosting air flow rate is increased to improve defrosting effectiveness, then the defrosting efficiency is improved, but the turbomachine performance is reduced
Solution Approach 1:
The cavity is segmented into a defrosting volume and a non-defrosting volume by the internal wall. The internal wall divides the space so that defrosting air flow is confined to only the portion near the conical external wall where frost forms, rather than circulating through the entire cavity. This segmentation allows effective defrosting with reduced air flow rate, avoiding the performance loss in the turbomachine.
2Reliability
If the defrosting air flow temperature is increased to improve defrosting effectiveness, then the defrosting efficiency is improved, but the turbomachine performance is reduced
Solution Approach 1:
The internal wall segments the cavity to create a dedicated defrosting volume adjacent to the conical external wall. This localized volume allows the defrosting air flow to concentrate its thermal energy on the frost-prone area, achieving effective defrosting without requiring excessive temperature increase that would compromise turbomachine performance.
3Device complexity
If the cavity volume is large then the supersonic speed attenuator structure is simple, but the defrosting efficiency is reduced
Solution Approach 1:
The internal wall is introduced to segment the large cavity into a smaller defrosting volume, creating a focused zone for heat exchange. This segmentation maintains the overall simple attenuator structure while significantly improving defrosting efficiency by concentrating the defrosting air flow action where it is most needed.
Solution Approach 2:
The internal wall creates a localized defrosting zone with specific thermal characteristics adjacent to the conical external wall. This local modification provides enhanced heat exchange properties in the critical area without altering the overall simple structure of the supersonic speed attenuator.
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 solution effectively prevents frost formation on the conical outer wall without impacting turbomachine efficiency, by concentrating heat exchanges in a calibrated defrost volume, maintaining the speed of the defrosting air flow, and avoiding additional energy expenditure.
Implementation Method 1
a defrosting air flow circulating to heat the conical external wall by heat exchanges
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
Disclosed is a supersonic speed attenuator (2) for an air inlet (5) of an aircraft power plant (8), comprising a conical external wall (20) with a tapered end (21) upstream and an internal dividing wall (22) that delimits, with the conical external wall (20), a cavity (23); the supersonic speed attenuator (2) further comprising a de-icing device (1) comprising: an internal wall (10) mounted in the cavity (23) opposite the conical external wall (20) so that, together, the two walls delimit a calibrated de-icing volume; at least one member (11) for supplying a de-icing air flow (FD), opening into the de-icing volume; and at least one member (12) for discharging the de-icing air flow (FD) from the de-icing space.