Clear Resin Additive Manufacturing Methods for Experimental Measurements with Applications to Gas Turbine Blade Cooling

This work reports detailed heat transfer measurements on two high-fidelity realistic gas turbine blade models that are additively manufactured from a clear resin material. The manufacturing procedures the authors have developed for producing these highly optically transparent models are documented here in detail, including discussions of the major challenges such as preventing warpage of the printed parts. These procedures have proven capable of producing transparent parts for a wide range of thermal fluid applications. This work demonstrates that capability by reporting highly detailed heat transfer coefficient contours on the blade interior surfaces obtained using a transient liquid crystal technique. Data is even captured on the top surfaces of the cooling features, including the ribs and pin-fins. The two models feature multi-inlet designs, with jet impingement in the leading edge, two ribbed midchord regions, and a trailing edge featuring a pin-fin array. The models differ in that one has sharp-cornered square features while the other has smoothly rounded features. The models are tested using a constant inlet pressure condition. Both models are shown to have very similar heat transfer performance, despite the squared model operating at a lower coolant mass flow rate for the same inlet pressure condition.