Common Questions About Cooling Holes in Turbine Blades

Professionals in the aerospace industry often inquire about the significance and measurement of cooling holes. Here are some frequently asked questions and the quick and dirty answers to help you understand the importance of these tiny holes. Some of these questions we already answered in this blog post. 

Accurately measuring these cooling holes presents significant challenges due to their complex geometries and diminutive sizes, often ranging from 0.3 to 1.2 mm in diameter. Traditional measurement techniques, such as tactile or fiber-probing systems, often fall short in capturing the intricate details required for thorough cooling hole inspection. Factors like irregular shapes, varying angles, and the need for high precision make conventional methods inadequate for ensuring the stringent quality standards demanded in aerospace applications.

Addressing these challenges, Bruker Alicona offers the µCMM, an optical high-precision coordinate measuring system that combines advanced Focus-Variation technology with Vertical Focus Probing. This innovative approach enables the measurement of vertical surfaces with inclination angles equal to or greater than 90°, capturing high-resolution, 3D data with approximately one million measurement points. Such detailed analysis ensures that every aspect of the cooling hole's geometry is accurately assessed.

By utilizing Bruker Alicona's µCMM and the specialized Cooling Hole Plug-in, manufacturers can achieve precise measurements of cooling hole parameters, including position relative to the datum system, diameter, funnel geometry, and minimum cylinder length. This level of precision ensures that each turbine blade meets the exacting standards required for optimal performance. Accurate measurement of cooling holes not only enhances turbine efficiency but also plays a crucial role in ensuring the safety and longevity of aerospace components.