Turbomachine Blade Cascade Detuning via Movable Elements
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Solution Overview
Problem
Existing blade cascades in turbomachines face challenges in reducing vibrational phenomena, particularly resonance, due to similarities in characteristic frequencies among blades, leading to inefficient detuning methods that can result in performance losses.
Innovation Solution
A blade cascade design featuring distinct groups of blade arrangements with identical element arrangements, systematically assigned based on type, to create differential characteristic frequencies, thereby enhancing vibrational dampening and reducing undesired vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If blades of diverse type are provided to detune characteristic frequencies, then vibrational phenomena are reduced, but device complexity increases
Solution Approach 1:
The patent applies local quality by providing attenuating elements only on specific blades (first blade arrangements) rather than all blades. These attenuating elements locally modify the characteristic frequencies of selected blades, creating detuning without requiring all blades to be of diverse types. This reduces the overall device complexity while still achieving vibrational reduction.
Solution Approach 2:
The patent changes physical parameters by introducing attenuating elements with specific mass properties that alter the characteristic frequencies of blades. By adjusting the mass, position, or configuration of these attenuating elements, the characteristic frequencies are modified to achieve detuning, reducing vibrational phenomena without changing the fundamental blade design.
2Object-affected harmful factors
If attenuating elements are added to blades, then characteristic frequencies are detuned, but device complexity increases
Solution Approach 1:
The patent segments the blade cascade into different groups: first blade arrangements with attenuating elements and second blade arrangements without such elements. This segmentation allows selective application of detuning measures only where needed, simplifying the overall system compared to applying attenuating elements uniformly across all blades.
Solution Approach 2:
The attenuating elements serve multiple functions: they detune characteristic frequencies to reduce resonance, and their movable mounting allows them to adapt to operational conditions. The same type of attenuating element can be used across different first blade arrangements, providing a universal solution that reduces complexity.
3Object-affected harmful factors
If different element arrangements are assigned to different blade types, then vibrational reduction is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by assigning specific element arrangements (first element arrangements identical to each other, second element arrangements identical to each other but different from first) to specific blade types. This targeted assignment enhances vibrational reduction effectiveness while limiting the number of different element arrangement types needed, thereby controlling manufacturing complexity.
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 effectively reduces undesired vibrations by detuning blade cascades more significantly than random or type-independent distributions, maintaining performance while ensuring rotational symmetry and frequency detuning.
Implementation Method 1
This approach effectively reduces undesired vibrations by detuning blade cascades more significantly than random or type-independent distributions, maintaining performance while ensuring rotational symmetry and frequency detuning.
Implementation Method 2
In order to reduce vibrational phenomena, in particular resonance phenomena, the characteristic frequencies of blade cascades can be detuned.
Data Source
AI summary
A blade cascade for a gas turbine, which has a first group with at least two, in particular at least three, first blade arrangements of the same type to one another, on which first element arrangements that are identical to one another and have at least one first element are movably mounted; and a second group with at least two, in particular at least three, second blade arrangements, which are of the same type to one another and are of different type from the first blade arrangements, on which second element arrangements, which are identical to one another and have at least one second element are movably mounted, wherein first and second element arrangements are different from each other.