Turbomachine Blade Tip Shroud Stiffness
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Solution Overview
Problem
Existing turbomachine designs face limitations in stiffness to weight ratio for tip shrouds, which restricts rotary blade tip coverage and efficiency due to weight constraints, affecting the overall performance of turbomachines.
Innovation Solution
A patterned structure of beams and cavities is integrated into the tip shroud of rotary blades, aligning the beams with stress and deflection directions to enhance stiffness while reducing weight, allowing for a larger tip shroud coverage and improved efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the size of the tip shroud is increased to provide desired stiffness, then the stiffness of the rotary blade is improved, but the weight of the tip shroud increases, limiting the available rotary blade tip coverage
Solution Approach 1:
The tip shroud is segmented into multiple reinforcing ribs that extend radially inward from the outer surface. These ribs divide the tip shroud into multiple structural zones, providing localized reinforcement without requiring a solid, weight-intensive structure. The ribs create a truss-like framework that maintains stiffness while reducing overall material usage.
Solution Approach 2:
The reinforcing ribs are strategically positioned at specific locations on the tip shroud where stress concentration occurs. Rather than uniformly thickening the entire tip shroud, the ribs are placed locally at critical points to provide maximum stiffness enhancement with minimum weight addition. This localized reinforcement approach addresses the contradiction by providing strength exactly where needed.
2Productivity
If the tip shroud size is increased to improve turbine efficiency, then the rotary blade tip coverage is improved, but the weight constraint limits further size increase
Solution Approach 1:
The tip shroud is divided into multiple reinforcing ribs that create a lightweight truss structure. This segmentation allows the tip shroud to achieve the necessary structural strength for larger size without proportionally increasing weight, thereby enabling improved turbine efficiency through enhanced tip coverage.
Solution Approach 2:
The tip shroud employs a composite structure combining the base shroud material with reinforcing ribs of the same material, creating a hybrid structure that optimizes the strength-to-weight ratio. This composite approach allows the tip shroud to be larger for improved efficiency while maintaining acceptable weight constraints.
3Stability of the object's composition
If a solid tip shroud design is used to ensure stability, then the structural integrity is improved, but the weight increases and manufacturing complexity increases
Solution Approach 1:
Instead of manufacturing a solid tip shroud, the structure is segmented into discrete reinforcing ribs that can be more easily formed and assembled. This segmentation simplifies manufacturing by allowing for thinner, more manageable rib sections that can be integrated into the tip shroud without requiring complex solid-forming operations.
Solution Approach 2:
The reinforcing ribs are positioned at specific locations where structural integrity is most critical, providing targeted support without requiring the entire tip shroud to be solid or overly complex. This localized approach maintains stability while reducing overall manufacturing complexity.
Data Source
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AI summary
A system includes a turbomachine (20) that includes a stator (60) and a rotor (24). The rotor (24) is configured to rotate about a rotational axis (26,36) relative to the stator (60). In addition, the rotor (24) includes a least one rotary blade (52), and the at least one rotary blade has a tip portion (64) with a patterned structure (54) of beams (56) and cavities (58).