Repeatability in performance of micro cooling geometries manufactured with laser powder bed fusion

Stringent regulations on aircraft engine emissions introduce a series restrictions on weight, size, and durability of all engine components to increase efficiency. In the hot section of a gas turbine engine, for example, airfoil internal cooling schemes must provide more efficient cooling with minimal mass flow. Such a requirement drives the cooling channels' size to the micro scale. One new tool currently being explored to achieve industry-required efficiencies can be found in advanced manufacturing techniques, such as laser powder bed fusion. However, as with all new technologies, the laser powder bed fusion process must be thoroughly investigated, fully understood, and achieve reliable and repeatable results before the process is widely implemented for gas turbine airfoils. This paper provides experimental results on the dimensions, as well as pressure loss and heat transfer performance, of microchannels manufactured using laser powder bed fusion; the microchannels mimic those suitable for airfoil internal cooling. Variability in the performance will be quantified for different builds, as well as for different materials.