Variable Thickness Thermal Barrier Coating for Turbomachine Airfoils
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Solution Overview
Problem
Conventional airfoils in turbomachines have uniform thermal barrier coatings that do not adequately address varying physical and temperature resistance needs across different areas of the airfoil, leading to insufficient protection against physical impacts and erosion.
Innovation Solution
The airfoil features a thermal barrier coating with a varying base layer thickness, with maximum thickness at the leading edge to enhance physical resistance in high-impact zones and a possible top coat, allowing for tailored protection across the aerodynamic surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a uniform thermal barrier coating is applied across the entire airfoil surface, then the manufacturing process is simple and consistent, but the physical resistance and erosion protection are insufficient in high-impact zones such as the leading edge
Solution Approach 1:
The patent applies local quality by varying the base layer thickness according to the specific functional requirements of different airfoil regions. The leading edge receives a thicker base layer (0.5-2.0 mm) for enhanced erosion and impact resistance, while the trailing edge receives a thinner base layer (0.1-0.5 mm). This localized differentiation optimizes protection where needed while maintaining manufacturing feasibility.
Solution Approach 2:
The thermal barrier coating is segmented into distinct functional layers with different thicknesses and properties. The base layer is divided into zones with varying thicknesses (thicker at leading edge, thinner at trailing edge), and a separate top coat layer provides additional protection. This segmentation allows each layer to be optimized for its specific protective function.
2Reliability
If the base layer thickness is increased at the leading edge to enhance physical resistance, then the erosion protection is improved, but the overall coating mass and potential stress on the substrate increase
Solution Approach 1:
The patent implements local quality by concentrating the thicker base layer (0.5-2.0 mm) specifically at the leading edge where erosion and impact risks are highest, while reducing the base layer thickness at the trailing edge (0.1-0.5 mm). This localized thickness variation provides maximum erosion protection where needed while minimizing unnecessary coating mass in lower-risk areas.
Solution Approach 2:
The patent applies partial action by providing excessive thickness (0.5-2.0 mm) of the base layer only at the leading edge where erosion protection is critical, rather than uniformly across the entire airfoil. This partial application of excessive thickness optimizes protection efficiency by concentrating material where it provides the most benefit.
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 solution provides improved resistance to physical impacts and erosion by maximizing base layer thickness at the leading edge, while maintaining a balanced mass distribution and overall coating thickness, enhancing the airfoil's durability in high-temperature environments.
Implementation Method 1
a thermal barrier coating on the pressure side surface and the suction side surface. The thermal barrier coating includes a base layer and a top coat
Implementation Method 2
A thickness of the base layer varies across each of the pressure side surface and the suction side surface with a maximum thickness of the base layer at the leading edge
Data Source
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AI summary
An airfoil (100) includes a root (102) and a tip (104), which define a span (128) of the airfoil (100) therebetween. The airfoil (100) also includes a leading edge (124) and a trailing edge (126) downstream of the leading edge (124) along a flow direction. The leading edge (124) and the trailing edge (126) each extend across the span (128) of the airfoil (100) from the root (102) to the tip (104). The airfoil (100) further includes a pressure side surface (120) and a suction side surface (122). The airfoil (100) also includes a thermal barrier coating (108) on the pressure side surface (120) and the suction side surface (122). The thermal barrier coating (108) includes a base layer (110) and a top coat (112). A thickness of the base layer (110) varies across each of the pressure side surface (120) and the suction side surface (122) with a maximum thickness of the base layer (110) at the leading edge (124).