Dual Mode Chemical Rocket Engine Using Low-Hazard Propellants
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Solution Overview
Problem
Current dual mode rocket propulsion systems rely on hazardous propellants like hydrazine and nitrogen tetroxide, which are toxic, carcinogenic, and environmentally detrimental, posing safety and handling challenges, and there is a need for alternatives with comparable performance.
Innovation Solution
A dual mode chemical rocket engine using low-hazardous liquid ADN- or HAN-based fuel-rich monopropellants and hydrogen peroxide, allowing operation in both monopropellant and bipropellant modes without electrical preheating, and utilizing existing catalysts and catalyst beds for hydrogen peroxide decomposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hazardous propellants like hydrazine and nitrogen tetroxide are used in dual mode rocket propulsion systems, then performance requirements are met, but safety and environmental concerns worsen due to toxicity and carcinogenicity
Solution Approach 1:
The patent changes the chemical composition parameters of the propellants by replacing hazardous hydrazine-based fuels with less toxic hydrocarbon-based fuels (such as RP-1, kerosene, or other hydrocarbons) while maintaining the dual-mode operational capability. This substitution maintains performance through optimized combustion chemistry while dramatically reducing toxicity and environmental harm.
Solution Approach 2:
The patent converts the previously harmful chemical properties of hydrazine and nitrogen tetroxide into beneficial alternatives by using hydrocarbon fuels that produce less harmful exhaust products. The combustion of hydrocarbons with oxygen produces primarily water vapor and carbon dioxide, which are significantly less toxic and environmentally damaging than hydrazine decomposition products.
2Adaptability or versatility
If electrical preheating systems are added to enable monopropellant mode operation, then operational versatility improves, but device complexity and cost increase
Solution Approach 1:
The patent designs a single propulsion system that can operate in multiple modes (monopropellant and bipropellant) without requiring separate heating systems for each mode. The catalytic converter serves as a universal component that can process both monopropellant fuels and the fuel component of bipropellant combinations, eliminating the need for mode-specific preheating infrastructure.
Solution Approach 2:
The catalytic converter is designed to be self-sufficient in generating the necessary reaction conditions. Instead of requiring external electrical heating systems, the catalyst bed naturally facilitates the decomposition and combustion reactions through its catalytic properties, using the chemical energy of the propellants themselves to initiate and sustain the reactions.
3Power
If catalyst beds are designed for high-temperature bipropellant combustion, then bipropellant mode performance improves, but catalyst durability worsens due to thermal degradation
Solution Approach 1:
The patent applies different catalytic materials or coating compositions to different regions or zones of the catalyst bed to optimize performance for specific operating modes. By creating local variations in catalytic properties, the system can handle the high-temperature demands of bipropellant combustion in certain zones while other zones provide thermal buffering and extended durability.
Solution Approach 2:
The catalyst bed uses composite material structures combining multiple materials with complementary properties. This could include support structures with high thermal stability, catalytic layers optimized for specific reactions, and protective coatings that resist thermal degradation. The composite structure allows the catalyst to withstand the harsh thermal environment of bipropellant combustion while maintaining long operational life.
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 provides a propulsion system with comparable performance to hazardous propellants, reducing safety concerns and environmental impact, with improved specific impulse and density impulse, and simplifying handling and fuelling operations.
Implementation Method 1
a primary reaction chamber for decomposition of hydrogen peroxide
Implementation Method 2
decomposition of hydrogen peroxide...catalytically decomposed in the primary reactor
Implementation Method 3
a secondary reaction chamber having means for injection therein of a liquid ADN- or HAN-based monopropellant...combusted in a secondary chamber
Data Source
Figure 1
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AI summary
The invention relates generally to dual mode bipropellant chemical rocket propulsion systems to be used in aerospace applications for 1) orbit raising, orbit manoeuvres and maintenance, attitude control and deorbiting of spacecraft, and/or 2) propellant settling, attitude and roll control of missiles, launchers and space planes. The present invention also relates to a dual mode chemical rocket engine for use in such systems. The engine uses low-hazardous storable liquidpropellants and can be operated either in monopropellant mode or in bipropellant mode. The monopropellants used are a low-hazard liquid fuel-rich monopropellant, and hydrogen peroxide, respectively.