Anamorphic Laser Drilling for Controlled Shaped Cooling Holes
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Solution Overview
Problem
Current methods for drilling shaped cooling holes in gas turbine engine components are costly, particularly when using machining processes like EDM, which can lead to component design avoiding such holes due to high costs compared to laser hole drilling.
Innovation Solution
A laser hole drilling system employing an anamorphic optical train with a cylindrical lens and a spherical lens offset from the optical axis, generating an asymmetric teardrop-shaped energy distribution to drill shaped cooling holes efficiently, allowing controlled breakthrough only at specific portions of the hole.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If machining processes like EDM are used to drill shaped cooling holes, then manufacturing precision and hole shape control are improved, but manufacturing cost increases significantly
Solution Approach 1:
The patent replaces the mechanical EDM machining process with a laser-based drilling system. The laser beam, shaped into an asymmetric teardrop profile through optical elements (cylindrical lens and spherical lens), directly drills the cooling holes without mechanical contact, thereby eliminating the high costs associated with EDM while maintaining precise hole shape control.
Solution Approach 2:
The patent changes the energy distribution parameters of the laser beam by using an anamorphic optical system. The cylindrical lens focuses the laser into a line, and the spherical lens transforms it into an asymmetric teardrop shape. By controlling laser parameters (power, pulse duration, focal position) and optical parameters (lens positioning, curvature), the system achieves precise control over hole shape and breakthrough characteristics without requiring expensive machining processes.
2Ease of manufacture
If laser hole drilling is used instead of machining processes, then manufacturing cost is reduced, but the ability to create shaped cooling holes with controlled breakthrough is limited
Solution Approach 1:
The patent introduces asymmetry into the laser beam energy distribution by positioning a spherical lens offset from the optical axis of the cylindrical lens. This asymmetric configuration creates a teardrop-shaped energy distribution with higher intensity on one side and lower intensity on the other, enabling controlled breakthrough at specific locations while maintaining the desired hole shape. The asymmetric optical arrangement allows the laser to mimic the capabilities of shaped charge drilling at a lower cost.
Solution Approach 2:
The patent transitions from conventional circular or symmetric laser beam profiles to a two-dimensional asymmetric teardrop profile by combining cylindrical and spherical lenses. This dimensional transformation of the energy distribution allows precise control over both the lateral dimensions (hole shape) and the depth dimension (breakthrough control), enabling shaped cooling holes to be drilled with a laser system rather than requiring mechanical machining.
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
Enables cost-effective laser drilling of shaped cooling holes, reducing manufacturing costs and allowing for the incorporation of complex cooling designs in gas turbine engine components without the need for expensive machining processes.
Implementation Method 1
a cylindrical lens along the optical axis downstream of the laser source
Implementation Method 2
a spherical lens downstream of the cylindrical lens to provide an anamorphic optical train, the spherical lens offset from the optical axis to generate an asymmetric teardrop shaped energy distribution at a focal plane
Implementation Method 3
Laser hole drilling is performed by focusing a laser (typically 1026 nm) onto the gas turbine component
Data Source
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AI summary
A laser hole drilling system. The system includes a laser source that generates a laser beam along an optical axis, a cylindrical lens along the optical axis downstream of the laser source, and a spherical lens downstream of the cylindrical lens, the spherical lens offset from the optical axis to provide an anamorphic optical train to generate an asymmetric teardrop shaped energy distribution at a focal plane.