Active Combustion Control Valve for Turbine Engine
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Solution Overview
Problem
Existing active combustion control systems for gas turbine engines are not effective in mitigating high-frequency combustion instability, particularly in high-performance propulsion systems, due to inaccuracies and failure risks associated with spring-based modulating valve constructions.
Innovation Solution
An active combustion control device with a housing and metering member that uses a translation and rotation component, driven by an electronic valve driver, to provide modulated fuel flow with precise amplitude, frequency, and phase matching that of the combustor fuel flow, offset by 180 degrees to stabilize combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spring-based modulating valve constructions are used, then the valve can be assembled and operated, but inaccuracies in flow modulation and susceptibility to failure occur
Solution Approach 1:
The patent removes the spring component entirely from the valve assembly. The spring-based modulating valve construction is replaced with a springless design where the valve stem directly actuates the valve disk without any spring mechanism, thereby eliminating the sources of imprecision and failure associated with springs while maintaining the essential flow modulation function
Solution Approach 2:
The patent replaces the mechanical spring system with an alternative actuation mechanism. Instead of using springs to provide restoring force and modulation, the invention uses a direct mechanical linkage between the valve stem and valve disk, potentially driven by pneumatic or electronic actuation systems, thereby substituting the unreliable spring-based mechanical system with a more precise and reliable alternative
2Reliability
If spring-based modulating valve constructions are used, then the valve can operate, but the assembly becomes difficult and the valve becomes susceptible to failure
Solution Approach 1:
The patent removes the spring component entirely from the valve assembly. The spring-based modulating valve construction is replaced with a springless design where the valve stem directly actuates the valve disk without any spring mechanism, thereby eliminating the sources of imprecision and failure associated with springs while maintaining the essential flow modulation function
Solution Approach 2:
The patent divides the valve into distinct modular components including the valve body, valve stem, valve disk, and seat. This segmentation allows each component to be manufactured and assembled independently, simplifying the overall assembly process and making the valve easier to manufacture and maintain while improving reliability through reduced complexity
3Reliability
If conventional active combustion control systems are used, then combustion instability can be addressed, but high-frequency combustion instability (1,000 Hz or more) cannot be effectively mitigated
Solution Approach 1:
The patent modifies the physical parameters of the fuel modulation system to enable high-frequency operation. This includes changing the mass and inertia of the moving components (valve stem, valve disk) to be sufficiently low, and adjusting the stiffness and damping characteristics of the actuation system, thereby enabling the valve to respond effectively to combustion instability frequencies of 1,000 Hz or more while maintaining combustion stability
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 effectively mitigates combustion instability by providing stable fuel flow with reduced pressure fluctuations, suitable for high-frequency operations in high-performance propulsion systems, enhancing engine efficiency and preventing hardware damage.
Implementation Method 1
sensors detect combustor dynamics and provide feedback signals to a controller, which in turn operates a control valve to modulate the fuel prior to injection into the combustor. The fuel amplitude, frequency and phase are modulated so that by cancellation of waves the pressure oscillation within the combustor is mitigated or offset entirely
Data Source
AI summary
An active combustion control device provides modulated fuel flow to the combustor of a turbine engine to mitigate combustion instability. The device includes a valve unit and an electronic valve driver controlling translation and rotation components in the valve unit that drive a metering member having a modulating end. The axial position and rotation of the end geometries relative to static flow ports inside the valve unit modulate the fuel flowing from the valve unit to the combustor atomizer. The amplitude and frequency of the modulated fuel flow match that of the instable combustor fuel flow and the phase is offset by 180 degrees so that the resultant fuel flow is at or near a stable state.