Segmented Shroud Blade Set for Turbopump Vibration Control
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Solution Overview
Problem
In turbopump turbines, weight reduction leads to increased resonant stress and vibration, causing potential blade breakage and complex vibration modes, and covering the entire blade with a shroud to mitigate this results in weight gain and further vibration issues.
Innovation Solution
A blade set design where a shroud is provided on the outer circumferential side, covering only the trailing edge side region of the blade, reducing weight and vibration while maintaining performance by controlling specific vibration modes through adjustable shroud dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the entire region from the leading edge side to the trailing edge side of the blade is covered with a shroud, then vibration is reduced, but weight increases
Solution Approach 1:
The shroud is segmented to cover only specific regions (either leading edge side or trailing edge side) rather than the entire blade span. This partial coverage approach reduces the shroud's weight while maintaining vibration control benefits in critical areas.
Solution Approach 2:
The shroud is applied locally to specific regions of the blade where vibration control is most needed, rather than uniformly across the entire blade. This allows optimization of vibration reduction effectiveness while minimizing weight penalty.
2Weight of moving object
If the turbine weight is reduced by making members thinner, then weight decreases, but resonant stress increases
Solution Approach 1:
The shroud acts as a counterbalancing structure that provides stiffness and damping to offset the increased resonant stress resulting from weight reduction. By adding the shroud selectively, the design compensates for the reduced structural mass without fully reversing the weight reduction benefit.
Solution Approach 2:
The blisk structure combines the blade and disc into an integrally formed composite structure, optimizing the distribution of material to reduce weight while maintaining strength. The selective shroud addition further refines this composite approach by adding stiffness only where needed.
3Weight of moving object
If the axial distance between blade rows is reduced, then weight decreases, but vibration coupling between blade and disc increases
Solution Approach 1:
The shroud is applied selectively to specific blade regions rather than uniformly, allowing vibration control in critical areas while maintaining weight reduction benefits from reduced axial spacing between blade rows.
Data Source
AI summary
A blade set of the present disclosure is exposed to a working fluid, which includes a blade main bodies which are disposed at intervals in a circumferential direction about an axis and each extending in a radial direction with respect to the axis wherein a tip end surface is formed on an outer circumferential side of each blade main body and the tip end surface of the blade main body includes a leading edge side region positioned on an upstream side in a flow direction of the working fluid along the axis and a trailing edge side region positioned on a downstream side in the flow direction, and a shroud which is provided on an outer circumferential side of the blade main bodies and covering either the leading edge side regions or the trailing edge side regions of the blade main bodies.