Variable Frequency Helmholtz Damper for Gas Turbine Pulsations
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Solution Overview
Problem
Traditional Helmholtz dampers in gas turbine engines have limited damping capability, particularly when faced with wide frequency ranges of pressure oscillations, and struggle to effectively dampen pulsations across different fuel operations, leading to potential engine damage and reduced output.
Innovation Solution
A variable frequency Helmholtz damper system that utilizes a purge medium temperature control unit to adjust the temperature of the purge medium, allowing the damping frequency to be varied and addressing both fuel gas and fuel oil pulsations within a limited volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional Helmholtz dampers are designed to address critical pulsation frequency ranges, then damping effectiveness is improved for specific frequencies, but the damper cannot effectively dampen pulsations across wide frequency ranges or different fuel operations
Solution Approach 1:
The patent applies the dynamics principle by making the Helmholtz damper frequency tunable through variable geometric parameters. The neck area and resonator volume can be dynamically adjusted to change the damping frequency, allowing the same damper to adapt to different pulsation frequency ranges encountered during various fuel operations and operating conditions.
Solution Approach 2:
The patent implements parameter changes by modifying the physical dimensions of the damper (neck area, resonator volume) to alter its resonant frequency. This allows the damping characteristics to be changed in response to varying operating conditions, enabling effective damping across a wide frequency range without requiring multiple fixed-frequency dampers.
2Adaptability or versatility
If multiple dampers are used to cover wide frequency ranges, then frequency coverage is improved, but the device complexity and volume increase
Solution Approach 1:
The patent applies universality by designing a single Helmholtz damper that can perform multiple damping functions across different frequency ranges. By making the damper tunable through variable geometric parameters, one damper structure can replace what would traditionally require multiple fixed-frequency dampers, thereby reducing overall system complexity.
Solution Approach 2:
The dynamic adjustability of the damper parameters allows a single device to cover the frequency range that would otherwise require multiple static dampers, simplifying the overall damper system while maintaining comprehensive frequency coverage.
3Adaptability or versatility
If mechanical variable damper components are used, then frequency adjustment capability is improved, but design practicality and component lifetime are reduced
Solution Approach 1:
The patent replaces mechanical variable damper components with a gas-permeable membrane system that provides frequency adjustment through non-mechanical means. The membrane allows gas permeation to dynamically change the resonator volume without moving parts, eliminating wear and reliability issues associated with mechanical adjustment mechanisms while maintaining frequency variability.
Solution Approach 2:
The gas-permeable membrane acts as an intermediary that enables frequency adjustment by controlling gas flow between the resonator and atmosphere. This intermediate component provides a reliable, wear-free mechanism for varying the damping frequency without requiring direct mechanical actuation of the resonator volume.
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 effectively mitigates engine pulsations across different fuel operations, reducing the risk of hardware damage and performance degradation, thereby enhancing the operational availability of the gas turbine engine.
Implementation Method 1
a purge medium temperature control unit for providing a flow of purge medium to the Helmholtz dampers, wherein the purge medium temperature control unit is in communication with a temperature control fluid flow such that the purge medium temperature control unit may vary the temperature of the flow of purge medium delivered to the Helmholtz dampers
Implementation Method 2
The resonance frequency (i.e., the damped frequency) of the Helmholtz damper may depend on the geometrical features of the resonator volume and the neck
Data Source
AI summary
The present application provides a variable frequency Helmholtz damper system for use with a combustor of a gas turbine engine. The variable frequency Helmholtz damper system may include one or more Helmholtz dampers and a purge medium temperature control unit for providing a flow of purge medium to the Helmholtz dampers. The purge medium temperature control unit may be in communication with a temperature control fluid flow such that the purge medium temperature control unit may vary the temperature of the flow of purge medium.