Turbomachine Blade Platform Wall Crest Curve Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional blades for turbomachines with both tip and root platforms are complex to fabricate, often requiring multiple molds or five-axis machining centers, making the process difficult and costly.
Innovation Solution
The blade design features platform walls with pressure and suction side portions meeting at a crest curve, where every point on these surfaces forms an acute or right angle relative to the fabrication direction, eliminating undercuts and simplifying fabrication, while maintaining aerodynamic performance by minimizing clearance angles and slope discontinuities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional blade designs with both tip and root platforms are used, then aerodynamic performance is maintained, but fabrication complexity increases requiring multiple molds or five-axis machining centers
Solution Approach 1:
The blade is segmented into distinct zones based on fabrication direction requirements. The platform walls are divided into first portions (with normals forming acute or right angles relative to first fabrication direction) and second portions (with normals forming acute or right angles relative to second fabrication direction). This segmentation allows different regions to be optimized for different manufacturing approaches, simplifying overall fabrication.
Solution Approach 2:
The invention introduces a dimensional classification system by defining surfaces relative to multiple fabrication directions. By categorizing surfaces based on their normal vector orientations relative to fabrication directions, the design enables simplified manufacturing through strategic orientation of geometric features.
2Ease of manufacture
If platform walls are designed with simplified fabrication surfaces, then manufacturing ease improves, but aerodynamic performance may be degraded due to slope discontinuities
Solution Approach 1:
Different regions of the blade are assigned different geometric qualities suited to their functional requirements. The platform wall portions are designed with specific normal vector characteristics (forming acute or right angles with fabrication directions) to eliminate undercuts, while the airfoil section maintains smooth continuous surfaces for optimal aerodynamic flow. This local optimization resolves the contradiction between manufacturability and performance.
Solution Approach 2:
The invention converts the potential harm of slope discontinuities into a benefit by strategically positioning them within the airfoil region where they are masked from the external flow. The discontinuities at platform walls are acceptable because they occur in regions shielded by the airfoil geometry, thus not degrading aerodynamic performance while enabling simplified fabrication.
Data Source
AI summary
A blade for a turbomachine bladed wheel, the blade comprising a root, an airfoil, and a tip. The root and the tip have respective platforms, each presenting a surface on a side toward the airfoil, which surfaces are referred to respectively as the root platform wall and the tip platform wall. Each of these platform walls is constituted by a pressure side portion and a suction side portion meeting at a crest curve.