Mentor: Jayanta Kapat
Description: Recent advances of additive manufacturing for high-temperature materials can enable novel design for advanced cooling technologies for hot-section components such as turbine blades, vanes or endwalls in a gas turbine engine or liners for rocket nozzles. This module is focused on one such technology for turbine airfoils – transpiration cooling. The current state-of-the-art for manufacturing of turbine airfoils is investment casting, followed by laser/EDM/waterjet drilling of film holes and deposition of bond coat and thermal barrier coating. During investment coating, a ceramic core is used to represent the internal cooling circuits and a ceramic shell is used to represent the external aerodynamic shape of the airfoil. Thus, a porous structure for the airfoil outer layer with controlled porosity and tortuosity cannot be created in the current state-of-the-art. In a recent study performed in this group, it was shown that laser additive manufacturing (LAM) can be successfully used in both a porous structure for transpiration cooling and an internal impingement sleeve. The objective of this research module is to characterize and quantify the cooling effectiveness for transpiration cooling and heat transfer coefficient distribution for impingement cooling for structures fabricated through LAM, in a fashion similar to the study of porous internal structure for turbine internal cooling undertaken earlier. The effectiveness of transpiration cooling will be studied with the help of temperature sensitive paint (TSP) or pressure sensitive paint, where the results will be presented. The heat transfer coefficient for the impingement heat transfer will be studied using the custom-fabricated heating foil attached to the target surface with TSP.
The graduate student and faculty mentor will guide the student very closely. The REU student will be tasked with quantifying the cooling effectiveness structures fabricated through LAM. A mix of experiments will be performed. The student’s summer training in ANSYS will be leveraged.
LAM-fabricated airfoil leading edge section from superalloy powder