Dosing Rotary Volumetric Pump for Rocket Propellant Supply
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Solution Overview
Problem
Current liquid propellant supply systems for rocket engines face challenges in precise control of propellant flow, especially during transition conditions, leading to thrust profile deviations and structural integrity issues, due to indirect pressure-based control methods which result in high Minimum Impulse Bit and increased inert mass.
Innovation Solution
The implementation of a liquid propellant supply assembly using dosing rotary volumetric pumps, which control propellant flow directly into the combustion chamber, allowing for precise and continuous control of propellant flow rates, reducing pressure dependence and minimizing inert mass by using low-pressure tanks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If indirect pressure-based control is used, then the system is simpler to implement, but the control precision and dynamics are insufficient
Solution Approach 1:
The patent replaces the indirect mechanical pressure-based control system with a direct electronic control system using a dosing pump. The dosing pump is controlled by a control unit that directly regulates the propellant flow rate, eliminating the need for complex pressure modulation and flow control valves. This substitution of control mechanisms achieves both simplicity and precision.
2Stress or pressure
If high-pressure tanks are used, then the propellant can be supplied at sufficient pressure, but the inert mass increases
Solution Approach 1:
The patent employs a dosing pump that can dynamically adjust its output pressure and flow rate as needed. Instead of using high-pressure tanks that maintain constant high pressure, the dosing pump supplies propellant at variable pressure levels, providing sufficient pressure for combustion while significantly reducing the inert mass of the propellant storage system.
3Measurement precision
If complex compensation operations are used, then the flow control accuracy improves, but the device complexity increases
Solution Approach 1:
The dosing pump is designed with inherent flow control capabilities that eliminate the need for external compensation operations. The pump's dosing mechanism automatically maintains accurate flow control through its internal design, such as precision metering chambers or controlled displacement mechanisms, without requiring additional compensation valves or complex control circuits.
4Power
If pressure loss modulation is used for thrust splitting, then the thrust control is achieved, but the system complexity and pressure requirements increase
Solution Approach 1:
The dosing pump performs preliminary action by precisely metering and dosing the propellant flow before it enters the combustion chamber. By controlling the flow rate at the source, the system achieves thrust splitting and modulation without needing complex pressure loss modulation devices, valves, or additional flow control elements downstream in the propellant supply system.
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 enables accurate control of thrust and mixing ratios, reducing structural stresses and inert mass, while improving specific impulse and compactness of the rocket engine, and minimizing pressure disturbances and cavitation risks.
Implementation Method 1
a dosing rotary volumetric pump (18) arranged in a pipe (16) between an outlet (10A) for the propellant from the tank (10) and an inlet (15) for the propellant in the injector nozzles (7) or in the combustion chamber (5)
Implementation Method 2
a combustion chamber (5) for the propellant and a known convergent-divergent nozzle (6) configured to generate a useful propulsion thrust when traversed by gases generated inside the combustion chamber (5)
Implementation Method 3
a known convergent-divergent nozzle (6) configured to generate a useful propulsion thrust when traversed by gases generated inside the combustion chamber (5)
Data Source
Figure 1
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AI summary
A combustion chamber (5) of a rocket engine (35) for a spacecraft is supplied with one or more liquid propellants stored in corresponding containing tanks (10, 37) under low pressure and moved toward the combustion chamber (5) by corresponding dosing rotary volumetric pumps (18, 38) under the control of a command, control, and synchronisation unit (22) configured to vary the rotation speed of each dosing rotary volumetric pump (18, 38) and to supply a flow of each propellant, which can be varied according to a required rocket engine operating profile, into the combustion chamber (5) .