Adaptive Rocket Nozzle Geometry via Layered Erosion
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Solution Overview
Problem
Conventional rocket motor nozzles face challenges in managing geometry changes during operation, particularly due to high temperature and pressure, which can lead to sudden changes in thrust and pressure cycling, and often require complex mechanisms like explosives for reconfiguration.
Innovation Solution
A rocket motor nozzle with alternating layers of relatively-low-erosion and relatively-high-erosion materials, made through resin-transfer molding, which erode at different rates to passively change the nozzle geometry during fuel burn phases, avoiding sudden changes and the use of explosives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional mechanisms (explosives) are used to change nozzle geometry during operation, then the nozzle can be reconfigured between thrust pulses, but the device complexity increases and sudden changes in thrust and pressure cycling occur
Solution Approach 1:
The nozzle is divided into multiple layers with different erosion characteristics. The layered structure allows progressive geometry changes as each layer erodes at a controlled rate, eliminating the need for complex explosive mechanisms while maintaining adaptability.
Solution Approach 2:
The patent replaces mechanical/explosive systems with a material-based solution. Instead of using explosives to change geometry, the design uses differential erosion of layered materials to passively achieve geometry changes, substituting a complex mechanical system with a simpler material property-based approach.
2Adaptability or versatility
If conventional mechanisms (explosives) are used to change nozzle geometry, then reconfiguration is possible, but sudden changes in thrust and pressure cycling occur
Solution Approach 1:
The nozzle geometry dynamically changes through controlled erosion of layered materials. The progressive exposure of layers with different erosion rates creates smooth, continuous geometry transitions rather than sudden changes, maintaining thrust stability while enabling adaptability.
Solution Approach 2:
The patent changes material parameters (erosion rates) across different layers to achieve gradual geometry evolution. By selecting materials with varying erosion characteristics, the design ensures smooth parameter transitions that prevent sudden thrust changes and pressure cycling.
3Ease of manufacture
If single-material nozzles are used, then manufacturing is simpler, but the nozzle cannot passively change geometry through differential erosion
Solution Approach 1:
The patent uses composite materials with different erosion characteristics arranged in layers. This composite structure enables passive geometry change through differential erosion while remaining manufacturable using resin transfer molding techniques, balancing manufacturing simplicity with functional adaptability.
4Speed
If high-erosion material is used throughout the nozzle, then geometry changes quickly, but the nozzle cannot maintain stable geometry during fuel burn phases
Solution Approach 1:
Different regions of the nozzle have different material properties. The patent applies high-erosion materials in specific layers and low-erosion materials in other layers, creating local quality variations that enable both stable geometry maintenance and controlled geometry changes at different locations and times.
Solution Approach 2:
The nozzle geometry evolves periodically through the sequential exposure of layers with different erosion rates. During fuel burn phases, the stable outer layers maintain geometry, while during transition phases, inner layers erode to change geometry, creating a periodic action that alternates between stability and change.
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 provides consistent thrust during multiple pulses, reduces pressure cycling, and eliminates the need for explosives, ensuring stable and efficient operation by gradually changing the nozzle geometry through controlled erosion.
Implementation Method 1
the relatively-high-erosion material layer is made of a relatively-high-erosion material that erodes more quickly when exposed to flow through the nozzle than does a relatively-low-erosion material or materials of the relatively-low-erosion material layers
Implementation Method 2
each of the pair of relatively-low-erosion material layers and the relatively-high erosion material layers include resin-transfer molded materials
Data Source
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AI summary
A rocket motor has a nozzle that is reconfigurable by erosion or ablation of the material around the throat of the nozzle. The nozzle throat has layers of materials with different erosion characteristics, with the erosion occurring so as to achieve the desired nozzle characteristics (configurations) during different parts of the fuel burn. The nozzle throat includes relatively-high-erosion material layers and relatively-low-erosion material layers, with some layers of the throat resisting erosion, while other of the layers erode or ablate relatively quickly. The relatively-low-erosion material layers may act as thermal barriers to fix the throat at relatively stable geometry for long periods of time, such as during most of the burn of different fuel segments, with the relatively-high-erosion material layers allowing rapid transition of the throat from one geometry to the next. The layers may be made by resin transfer molding (RTM).