Passive Gas Ejection Modulation for Nozzle Thrust Optimization
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Solution Overview
Problem
Existing nozzle designs with a single throat section are inadequate for propellants operating in both high and low flow rate regimes, requiring a variable throat section to optimize thrust coefficient, but existing solutions with active positioning systems are complex and prone to failures due to the need for an external energy source.
Innovation Solution
A passive modulation device within the nozzle that uses a partial closure element, a control guide, a main piston, and a cocking piston to adjust the gas ejection section based on pressure changes, allowing for two operating modes without an external energy source, utilizing springs and ball mechanisms to lock and unlock movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single throat section is used in the nozzle, then the structure is simple and reliable, but the thrust coefficient cannot be optimized for both high and low flow rate operating regimes
Solution Approach 1:
The nozzle throat section is made variable through a mobile closure element that can be positioned at different locations along the throat axis. This dynamic adjustment allows the effective throat area to be changed according to operating conditions, enabling optimization of the thrust coefficient for both high and low flow rate regimes while maintaining a relatively simple overall nozzle structure
2Ease of operation
If an active positioning system with external energy source is used to control the mobile needle, then the ejection section can be precisely modulated, but the device complexity increases and the risks of breakdown or faulty operation increase
Solution Approach 1:
The mobile closure element is actuated passively by the combustion gases themselves through pressure differential forces. When the chamber pressure exceeds a predetermined threshold, the gas pressure automatically moves the closure element to the desired position without requiring external energy sources, active control systems, or complex actuators. This self-service mechanism significantly improves reliability by eliminating potential failure points associated with active positioning systems while maintaining precise ejection section modulation
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
Enables optimal thrust coefficient adjustment across different pressure levels by passively modulating the gas ejection section, ensuring reliable operation without external energy, thus enhancing the performance and reliability of the nozzle across varying flow rates.
Implementation Method 1
the cocking piston moving from the rest position to the cocking position when the pressure in the modulation device reaches a first predetermined value
Implementation Method 2
the main piston moving from the first position to the second position when the arming piston is in its arming position and when the pressure in the modulating device reaches a second predetermined value lower than the first predetermined value
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
A device for modulating a gas ejection section (100) comprising a partial sealing member (111) for partially sealing a nozzle neck (13), a control guide (112) for controlling the sealing member (111), a main piston (120) and a priming piston (130). The control guide (112) is movable between a retracted position in which the partial sealing member (111) is retracted relative to the nozzle neck (13) and a sealing position in which the partial sealing member (111) is in contact with the nozzle neck (13). The priming piston (130) is movable between an idle position and a priming position of the main piston (120) when the pressure in the modulation device reaches a first predefined value. The main piston (120) is movable between a first locked position that locks the movement of the control guide (112) in the retracted position of same and a second locked position that locks the control guide (112) when the pressure in the modulation device reaches a second predefined value lower than the first predefined value.