Hollow Core Airfoil Wall Thickness Measurement via Conical Mold Core
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
It is challenging to accurately check the wall thickness of hollow airfoils in gas turbine engines, particularly at complex and hard-to-reach locations, due to the intricate design and internal cooling channels.
Innovation Solution
Incorporating a cone-shaped mold core that leaves a wall thickness indicator in the airfoil after the mold core is leached away, allowing inspectors to assess the opening size to ensure proper wall thickness, with varying cone shapes and designs to indicate whether the wall is too thick or too thin based on the opening diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If traditional mold cores are used without wall thickness indicators, then the airfoil can be formed with complex internal cooling channels, but it becomes difficult to check the wall thickness at hard-to-reach locations
Solution Approach 1:
The mold core is designed with a conical indicator feature that extends into the airfoil wall during casting. This preliminary inclusion of the measurement indicator allows for easy wall thickness verification after the airfoil is formed, eliminating the need for complex post-processing measurements at hard-to-reach locations.
Solution Approach 2:
The conical indicator on the mold core serves as an intermediary measurement feature. It translates the internal wall thickness (which is difficult to measure) into an external opening dimension (which is easy to measure). The diameter of the conical opening directly corresponds to the wall thickness, providing a simple visual and physical indicator.
2Productivity
If the airfoil wall thickness is not properly controlled, then manufacturing can proceed without additional inspection steps, but the wall may be too thin or too thick affecting performance and safety
Solution Approach 1:
The mold core with the conical indicator makes the airfoil self-indicating regarding wall thickness. The casting process itself creates the measurement feature, and the finished airfoil contains its own wall thickness indicator in the form of the conical opening. This eliminates the need for separate, time-consuming inspection procedures while maintaining precision.
Solution Approach 2:
The conical opening provides a visual indication of wall thickness through its diameter. Inspectors can visually assess whether the opening (and thus the wall thickness) is within acceptable ranges, providing immediate feedback without requiring complex measurement instruments or time-consuming procedures.
3Object-affected harmful factors
If conventional inspection methods are used, then non-invasive measurement is maintained, but accurate wall thickness checking at complex locations is not achieved
Solution Approach 1:
The conical indicator acts as an intermediary that transforms the internal wall thickness measurement problem into an external dimension measurement. Inspectors measure the diameter of the conical opening from the outside, which directly correlates to the internal wall thickness, achieving accurate measurement without invasive procedures.
Solution Approach 2:
The solution transitions the measurement from one dimension (internal wall thickness) to another dimension (external opening diameter). By measuring the diameter of the conical opening on the external surface, inspectors indirectly but accurately determine the internal wall thickness without needing to access or measure the internal geometry directly.
Data Source
AI summary
A molding technique is utilized to form the cooling channels in an airfoil for a gas turbine engine. The cooling channels are formed by lost core mold cores, which are leached away after metal has been molded around them. At least one of the mold cores is provided with a cone which will extend into the airfoil. The cone forms an opening in a wall of the airfoil, and the size of this opening is indicative of the thickness of the wall. By comparing the size to expected sizes, a determination can be made of whether the wall is of an acceptable thickness at locations where it is difficult to otherwise measure the wall.