Rocket Motor Feed Sonic Choke for Passive Propellant Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rocket motor feed systems using active feed systems with pumps or blowdown systems are complex and expensive, and they require active regulation of propellant flow, which can lead to inefficiencies and increased risk of failure.
Innovation Solution
A rocket motor feed system that includes a sonic choke to passively regulate the mass flow rate of gas, using self-pressurized propellants to establish sonic flow conditions, and an injector to isolate the upstream feed line from the downstream combustor, eliminating the need for pumps or blowdown systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If active feed systems with pumps or blowdown systems are used, then a specified mass flow rate of propellant can be delivered, but the system becomes complex and expensive
Solution Approach 1:
The patent replaces active mechanical feed systems (pumps, blowdown systems) with a passive sonic choke system. The sonic choke uses the physics of sonic flow through a restricted orifice to automatically regulate mass flow rate without mechanical moving parts, thereby eliminating system complexity while maintaining productivity
Solution Approach 2:
The sonic choke system is self-regulating and requires no external control mechanisms. The mass flow rate is automatically controlled by the sonic flow physics through the choke orifice, making the system self-service and eliminating the need for active mechanical components
2Productivity
If active feed systems with pumps or blowdown systems are used, then a specified mass flow rate of propellant can be delivered, but the cost increases
Solution Approach 1:
The patent replaces expensive active mechanical feed systems with a simple passive sonic choke consisting of a restricted orifice. This substitution dramatically reduces manufacturing cost while maintaining the ability to deliver specified mass flow rates
Solution Approach 2:
The sonic choke uses a simple, inexpensive orifice structure that can be easily manufactured and replaced if needed, eliminating the need for expensive, complex mechanical pumps and blowdown systems
3Productivity
If active regulation of propellant flow is used, then mass flow rate can be controlled, but reliability decreases due to increased risk of failure
Solution Approach 1:
The patent replaces active mechanical regulation systems with a passive sonic choke that has no moving parts. The mass flow rate is controlled by the inherent physics of sonic flow through the orifice, eliminating mechanical failure modes and significantly improving system reliability
Solution Approach 2:
The sonic choke system automatically regulates mass flow rate without requiring external control mechanisms or active components, making it inherently more reliable as it eliminates the failure points associated with active regulation systems
4Stability of the object's composition
If an injector is used to isolate the upstream feed line from the downstream combustor, then predictable mass flow rate is achieved, but device complexity increases
Solution Approach 1:
The injector acts as an intermediary component between the feed line and combustor, using a restricted orifice to create a pressure drop that isolates the upstream feed line from the downstream combustor. This intermediary structure achieves stable mass flow rate while adding minimal complexity
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 system provides a predictable and constant mass flow rate, reducing complexity, increasing reliability and longevity, and enabling regenerative cooling, while maintaining a stable oxidizer-to-fuel ratio for efficient combustion.
Implementation Method 1
a sonic choke provided in the feed line, the sonic choke being configured to passively regulate the mass flow rate of gas passing therethrough
Data Source
AI summary
A rocket motor and rocket motor feed system are disclosed. The rocket motor feed system includes a sonic choke which passively regulates the mass flow rate of gaseous propellant passing through the sonic choke. An injector is provided and isolates the upstream feed line of the rocket motor feed system from a combustor. Regenerative cooling circuits are disclosed. Self-pressurised gaseous propellants may be used with the rocket motor and rocket motor feed system. Suitable propellants are disclosed. Bi-propellants may be used. The sonic choke may provide a ratio of oxidiser:fuel to a combustor. Rocket motor feed systems with separate fuel and oxidiser branches are also disclosed. A rocket motor utilising such a feed system is disclosed.