Rotor Blade Cooling Passage Layout for Lower Pressure Loss
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Solution Overview
Problem
The existing gas turbine blade designs experience a reduction in cooling effect and strength due to the formation of turndown extension portions, which lead to increased pressure loss and decreased convective cooling efficiency.
Innovation Solution
A blade design that eliminates the turndown extension portion by forming a communication passage directly from the shaft-side surface to the blade passage, allowing cooling air to flow linearly from the blade passage to the platform passage, thereby maintaining strength and enhancing cooling efficiency without the need for a turndown extension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a turndown extension portion is formed to connect the blade passage and platform passage, then the cooling air can flow between passages, but the blade strength is reduced and the cooling effect on the gas path surface is decreased
Solution Approach 1:
The invention extracts and eliminates the problematic turndown extension portion from the blade structure. By removing this unnecessary structural element, the patent achieves both improved blade strength and maintained cooling air flow connectivity through alternative passage configurations that directly connect the blade passage and platform passage without requiring the turndown extension.
2Ease of operation
If a turndown extension portion is formed to connect the blade passage and platform passage, then the passages can communicate, but the convective cooling efficiency is decreased due to velocity component loss
Solution Approach 1:
The invention applies preliminary action by pre-configuring the blade passage and platform passage with appropriate orientations and positions before the cooling air flow occurs. The passages are designed with directions that facilitate smooth, high-velocity air flow from the blade passage to the platform passage, eliminating the need for the turndown extension portion that would cause velocity loss and reduce convective cooling efficiency.
3Ease of operation
If the communication passage is formed through machining after casting, then the communication is achieved, but the manufacturing complexity increases
Solution Approach 1:
The invention merges the communication passage formation into the casting process itself by incorporating cores that define the blade passage and platform passage configurations. This integration eliminates the need for separate post-casting machining operations to create the communication passage, thereby reducing manufacturing process complexity while achieving the required passage connectivity.
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 design reduces pressure loss and maintains the cooling effect on the gas path surface near the blade body, enhancing the overall performance and strength of the blade.
Implementation Method 1
an opening of the communication passage in the at least one surface is blocked with a sealing member
Implementation Method 2
cooling air flows from the blade passage into the platform passage through the communication passage
Implementation Method 3
the effect of convective cooling by the cooling air flowing through the turndown extension portion decreases accordingly
Implementation Method 4
a blade passage through which cooling air flows is formed inside the blade body, the platform, and the shaft-mounted part
Data Source
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AI summary
A blade (50) has a blade passage (71) extending in a blade height direction (Dwh), a platform passage (81) formed inside a platform (60), and a communication passage (75) leading from an outer surface (93) of a shaft-mounted part (90) through the platform passage (81) to the blade passage (71). An inner surface defining an inflow passage portion (82) of the platform passage (81) includes a shaft-side inner surface (88) that faces a gas path side. The shaft-side inner surface (88) spreads in a direction having more of a component of a blade thickness direction (Dwt) than a component of the blade height direction (Dwh). An inner surface defining the communication passage (75) joins to the shaft-side inner surface (88).