Development of Experimental Methodology to Determine the Heat Transfer of Additively Manufactured Airfoil Channels in a High-Speed Linear Cascade Rig

Résumé du livre

A developed methodology for determining the internal heat transfer coefficient within a high speed linear cascade rig at steady state conditions is proposed. The methodology outlined in this study is essential to an end goal of rapid concept selection of internal cooling schemes for gas turbine engine applications. Additive manufacturing played an important role in the development and complex instrumentation of linear cascade, airfoil hardware. Additionally, additive manufacturing methods support the goal of rapid concept selection due to the advantage of having a quick turnaround time in comparison to traditional airfoil manufacturing methods. The multiple cascade hardware sets that were developed each implement a different internal cooling channel design scheme. The complex instrumentation that was designed into the hardware, via additive manufacturing, was utilized to evaluate and compare heat transfer and friction factor effects. A computational analysis tool was used to produce mock test data of the cascade hardware, which allowed for the development of the heat transfer methodology via data reduction. The heat transfer and friction factor results from CFD were compared to the methodology data reduction and an agreement between the two was identified; a 0.2% difference in internal heat transfer coefficient was found. The validation of the methodology via computational means is an essential step toward linear cascade testing validation. Testing of a baseline, empty microchannel cascade hardware is underway to achieve full-fledged validation of the proposed methodology. Preliminary friction factor results indicate agreement with literature for channels that have similar hydraulic diameters, whereas heat transfer results indicate the need for further development due to obstacles impacting repeatability.