Hybrid Rocket Thrust Vector Control via Fluid Injection
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Solution Overview
Problem
Standard hybrid rocket engines suffer from slow solid-fuel regression rates, low volumetric loading, and poor combustion efficiency due to varying oxidizer to fuel ratios, limiting their specific impulse and preventing commercial spaceflight applications.
Innovation Solution
A thrust chamber assembly with high volumetric specific impulse solid polymer fuel, where the thermorheological properties are controlled to maintain a constant fuel mass flow and optimal stoichiometric combustion, combined with a divergent nozzle section for thrust vector control using additive manufacturing for reduced complexity and increased payload capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If standard hybrid rocket engines use conventional solid fuel configurations, then the engine structure is simple, but the fuel regression rate is slow and combustion efficiency is poor
Solution Approach 1:
The solid fuel is divided into multiple segments or layers with different regression rate characteristics. This segmentation allows different portions of the fuel to regress at optimized rates, improving overall combustion efficiency while maintaining a relatively simple engine structure without requiring complex injection systems.
Solution Approach 2:
The fuel properties are changed by varying composition, density, or physical characteristics across different fuel layers. This parameter change enables control over regression rates and combustion efficiency without adding mechanical complexity to the engine architecture.
2Reliability
If hybrid rocket engines operate with varying oxidizer to fuel ratios, then the engine can accommodate fuel consumption changes, but the specific impulse cannot be maintained at peak value
Solution Approach 1:
The engine incorporates feedback mechanisms that monitor the oxidizer to fuel ratio during operation and adjust oxidizer flow rates accordingly. This feedback control maintains the optimal stoichiometric ratio throughout the burn, preserving peak specific impulse while accommodating fuel consumption changes.
Solution Approach 2:
The oxidizer flow rate is made dynamic and adjustable during the burn process rather than being fixed. This dynamic adjustment allows the system to maintain optimal combustion conditions throughout the fuel consumption cycle, preserving energy efficiency while adapting to changing fuel mass.
3Device complexity
If pressure-fed cycles are used to power propellant injection, then component complexity is reduced, but propellant pressure and combustion chamber pressure are limited
Solution Approach 1:
The patent replaces the pressure-fed mechanical injection system with a different mechanism such as capillary action, surface tension effects, or alternative fluid delivery methods. This substitution reduces dependence on high propellant pressure while maintaining injection functionality, thereby reducing the need for heavy pressure-containing structures.
Solution Approach 2:
The injection system utilizes porous materials that enable propellant delivery through capillary forces rather than pressure-driven flow. This approach allows effective propellant injection at lower pressures, reducing the structural requirements for pressure containment while maintaining injection performance.
4Productivity
If high pressure propellant tanks are used to increase combustion chamber pressure, then performance is improved, but tank weight increases reducing payload capacity
Solution Approach 1:
The patent replaces high-pressure mechanical storage and delivery systems with alternative mechanisms such as gravity-fed tanks, capillary action systems, or low-pressure injection methods. This substitution enables combustion chamber pressure to be maintained through more efficient means rather than relying solely on high propellant storage pressure, reducing tank wall thickness and weight.
Solution Approach 2:
The system changes the operating pressure parameters of the propellant storage and delivery system. By operating at lower propellant storage pressures while maintaining effective combustion chamber pressure through alternative injection mechanisms, the tank structural requirements are reduced, decreasing weight while preserving performance.
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 enables consistent high specific impulse and combustion performance, reducing mechanical complexity and increasing payload capacity by maintaining a constant oxidizer to fuel ratio and allowing for flexible mission designs.
Implementation Method 1
The combustion process of liquefying solid polymer fuels may involve sequential vaporization and combustion of droplets vapors in the gas phase
Implementation Method 2
combustion of droplets vapors in the gas phase
Implementation Method 3
a thrust vector control device operatively connected to the divergent section of the nozzle and operable to inject a fluid through at least one aperture defined through the divergent section for controlling a direction of a thrust
Data Source
AI summary
A hybrid rocket engine system has: an oxidizer tank containing a liquid oxidizer; a rocket engine having a combustion chamber operatively connected to the oxidizer tank; a solid propellant fuel within the combustion chamber; a nozzle fluidly connected to the combustion chamber, the nozzle having a convergent section and a divergent section downstream of the convergent section; and a thrust vector control device operatively connected to the divergent section of the nozzle and operable to inject a fluid through at least one aperture defined through the divergent section for controlling a direction of a thrust generated by the rocket engine.