Rocket Motor Thrust Control via Valve Area Reconfiguration
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Solution Overview
Problem
Existing propulsion systems using solid propellant rocket motors face inefficiencies in thrust control due to sensitivity to burn rate variations and propellant mass flow discrepancies, leading to wasted propellant and inefficient motion control.
Innovation Solution
A propulsion thrust control system that configures valves based on a commanded propellant mass flow discharge rate and net thrust commands, continuously reconfiguring total valve area to minimize wasted propellant and optimize efficiency, using a controller to regulate valve areas according to propellant mass flow discharge rates and thrust requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pressure measurements are used as control inputs to regulate valve states, then thrust control is achieved, but propellant waste increases due to sensitivity to burn rate variations and mass flow discrepancies
Solution Approach 1:
The patent implements a feedback control system that continuously monitors actual thrust or mass flow rate and compares it with commanded values. The controller adjusts valve positions based on the error between commanded and actual thrust/mass flow, creating a closed-loop system that compensates for burn rate variations and minimizes propellant waste while maintaining accurate thrust control
Solution Approach 2:
The patent replaces traditional pressure-based mechanical control with an electronic control system that directly regulates valve positions based on thrust or mass flow commands. This substitution allows for more precise control with finer resolution, reducing the propellant waste that occurs with coarse pressure-based valve control
2Adaptability or versatility
If proportional valves with partially open states are used, then thrust variation is enabled, but system complexity increases
Solution Approach 1:
The patent employs dynamic valve control where proportional valves are continuously adjusted to partial open states based on real-time thrust requirements. The controller dynamically modulates valve positions rather than using fixed discrete positions, enabling smooth thrust variation while managing system complexity through electronic control algorithms
3Adaptability or versatility
If multiple rocket engines or gas generators are employed for attitude control, then roll and pitch/yaw control is achieved, but assembly weight increases due to additional hardware
Solution Approach 1:
The patent makes the main rocket engine nozzle multi-functional by enabling it to perform both primary thrust generation and attitude control functions. By controlling the nozzle to gimbal or vector thrust, the same engine provides both propulsion and attitude control, eliminating the need for separate attitude control thrusters and reducing overall assembly weight
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 approach minimizes propellant waste and enhances thrust control efficiency by directly managing propellant mass flow and thrust distribution, improving the overall performance of rocket-propelled vehicles.
Implementation Method 1
a propellant comprising a solid fuel charge or 'grain' which burns to generate exhaust gases and other combustion products
Implementation Method 2
expelled through one or more nozzles of the rocket motor to provide thrust
Data Source
AI summary
A propulsion thrust control system and method for controlling thrust in a rocket motor includes configuring valves of an energized rocket motor to an initial total valve area according to a total thrust command. The total thrust command is converted into a commanded propellant mass flow discharge rate. A varying total valve area is computed from an error between the commanded propellant mass flow discharge rate and a calculated propellant mass flow discharge rate. The valves are reconfigured according to a distribution of the varying total valve area. The propulsion system includes a pressure vessel with valves and a controller for regulating the valve area according to a propellant mass flow discharge rate from the pressure vessel.