Gas Turbine Blade Squealer Tip Cooling via Chamfered Rail
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Solution Overview
Problem
The radial clearance between the tip of a gas turbine blade and the stator surface is critical to prevent gas leakage and contact damage, but existing cooling methods for the squealer tip are vulnerable to blockage during rub events, reducing efficiency and risking structural damage.
Innovation Solution
A gas turbine blade design featuring a chamfered suction side rail with strategically positioned squealer tip cooling holes, where the outlets are located on the chamfer surface to prevent blockage during rub events, ensuring continuous cooling and increased heat resistance with a thermal barrier coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling holes are disposed at the squealer tip to cool it, then the cooling effectiveness is improved, but the cooling holes may get damaged or blocked during rub events
Solution Approach 1:
The outlet of the cooling hole is positioned on the chamfer surface, which is an inclined surface transitioning from the outer surface to the inner surface of the squealer tip. This dimensional repositioning moves the outlet away from the radial clearance zone where rub events occur, preventing blockage while maintaining cooling effectiveness through the chamfer geometry
Solution Approach 2:
The chamfer surface acts as an intermediary structure between the cooling hole outlet and the stator surface. It provides a geometric transition that directs cooling flow away from potential contact zones while still allowing the cooling function to operate effectively on the squealer tip
2Loss of energy
If the radial clearance is kept small to minimize gas leakage, then the efficiency is improved, but the risk of accidental contact between the squealer tip and stator surface increases
Solution Approach 1:
The chamfer is pre-formed on the squealer tip structure before operation. This preliminary geometric feature prepares the cooling hole outlet to discharge in a direction that avoids the stator surface, providing proactive protection against rub event damage while enabling the use of smaller radial clearances for improved efficiency
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
The design maintains efficient cooling of the squealer tip while minimizing the risk of blockage and structural damage, enhancing the overall performance and efficiency of the gas turbine by maintaining a small radial clearance and preventing heat input from hot gases.
Implementation Method 1
a portion of the cooling fluid in the cooling path is discharged from the turbine blade through the tip cooling holes
Implementation Method 2
increased heat resistance with a thermal barrier coating
Data Source
Figure 1
Figure 2~3
Figure 4A~4B
AI summary
The present technique presents a blade 1 for a gas turbine 10. The blade 1 includes an airfoil 100 having an airfoil tip part 100a and a pressure side 102 and a suction side 104 meeting at a leading edge 106 and a trailing edge 108 and defining an internal space 100s of the airfoil 100. A squealer tip 80, 90 is arranged at the airfoil tip part 100a. The squealer tip 80, 90 comprises a suction side rail 90. The suction side rail 90 comprises a chamfer part 90x and at least one squealer tip cooling hole 99. The chamfer part 90x comprises a chamfer surface 9. An outlet 99a of the at least one squealer tip cooling hole 99 is disposed at the chamfer surface 9.