First principles Calculations of Optical Properties for Minimizing the Radiative Heat Flux in Thermal and Environmental Barrier Coating Materials
Abstract
In applications such as aviation jet engines, where temperatures as high as 1500C are common in the hottest sections, the total heat flux arises from the conductive and radiative heat transfer modes. The past decade witnessed tremendous advancement in theory, experiments, and metrology for understanding the contributions from the conductive term. Many novel thermal and environmental barrier coating (T/EBC) materials with low thermal conductivity at high-temperatures have been experimentally discovered. It is now well-acknowledged that we are fast approaching the physical limit, where further reduction in the total heat flux by lowering the thermal conductivity cannot be expected to yield transformative reduction. The attention has now shifted to the radiative term, where we have an exciting opportunity to minimize the total heat flux through defect engineering. The objectives of this work will be to calculate the optical properties, of promising T/EBC materials using first principles methods. The proposed computational work will uncover the hitherto unknown fundamental structure-property relationships needed for tailoring the optical properties of promising T/EBC materials to minimize the radiative heat flux at extreme environments. We will use density functional theory (DFT) and beyond-DFT methodsto accomplish the objectives. In addition, we will also develop a data analytics approach to rapidly down-select promising compounds with low thermal conductivity at high-temperatures and desired coefficient of thermal expansion values to minimize the elastic strain energy between the coating and the substrate.Approved for Public Release
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 05, 2021
- Source ID
- N000142112479
Entities
People
- Prasanna V Balachandran
Organizations
- Office of Naval Research
- United States Navy
- University of Virginia