Gas Turbine Rotor Blade Vibration Damper Design
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Solution Overview
Problem
Gas turbine engines face challenges in reducing vibratory stresses in rotor blades due to rotational vibrations, which existing dampers may not adequately address, leading to potential damage and inefficiency.
Innovation Solution
A rotor blade vibration damper with an elongated body and radially extending tabs is designed to fit within the cavities formed by adjacent blades, allowing radial displacement and providing additional damping through frictional contact, thereby reducing vibratory stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing dampers are used to reduce vibratory stresses in rotor blades, then vibration damping is provided, but the dampers may not adequately address rotational vibrations and add weight causing additional centrifugal forces
Solution Approach 1:
The damper is divided into multiple functional segments: a friction element with front and rear tabs for radial displacement and damping, a central body for structural support, and integration features for mounting between blade roots. This segmentation allows each part to perform its specific function efficiently while minimizing overall weight.
Solution Approach 2:
The damper employs local quality by concentrating damping material and friction surfaces only where needed - specifically at the front and rear tabs that contact the blade roots. The central body uses lighter structural material, optimizing the distribution of mass to provide maximum damping with minimum weight.
2Loss of energy
If dampers are designed to dissipate energy through friction, then vibratory energy is absorbed, but the friction contact may generate heat and wear
Solution Approach 1:
The friction between the damper tabs and blade roots, which would normally generate harmful heat and wear, is converted into a beneficial damping mechanism. The controlled friction dissipates vibratory energy effectively while the heat generated is minimal and manageable within the blade root cavity.
Solution Approach 2:
The damper design changes the parameters of friction contact by using specific surface areas, contact pressures, and material properties at the tabs to optimize energy dissipation while controlling temperature rise. The friction coefficient and contact geometry are selected to balance damping effectiveness with thermal management.
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 damper effectively absorbs vibratory energy, converting it into heat and reducing stress on the blades, while maintaining a lightweight design to avoid additional centrifugal forces, thus enhancing the operational stability and efficiency of the gas turbine engine.
Implementation Method 1
Dampers may be used to reduce some of the vibrations transmitted to the blades by dissipating energy through friction between the damper and the blade it is mounted on
Data Source
AI summary
A rotor blade vibration damper for a gas turbine engine includes an elongated damper body including a top portion extending longitudinally between a front end and a rear end. The top portion has a width defined between spaced apart lateral sides and is substantially flat between the front and rear ends and between the lateral sides such as to define a longitudinal plane within which the top portion lies. A front tab extends downwardly from the front end of the top portion relative to the longitudinal plane. The rear end of the top portion is flat and generally contained in the longitudinal plane. A pair of lateral tabs extends downwardly from each of said lateral sides of the top portion relative to the longitudinal plane.