Prediction of Thermal Transport in Nonmetallic Materials at Ultra-high Temperatures

University Of Utah, Salt Lake City UT

Investigators

Abstract

The development of many cutting-edge technologies requires an ultra-high-temperature working environment. For example, the next-generation gas turbines need to be able to work at 1300 degrees Celsius, to boost efficiency and save energy. The next-generation hypersonic passenger aircraft and re-entry vehicles need to withstand 1000-3000 degrees Celsius at the leading edges without material loss. The next-generation nuclear fission plant and other thermal power plants are desired to work at higher temperatures for higher energy-conversion efficiency and lower greenhouse gas emissions. The development of future fusion plants requires even higher temperatures. All these technologies require effective management of heat flow at ultra-high temperatures. However, the fundamental thermal transport processes in materials at ultra-high temperatures remain unclear. It is therefore necessary to develop theories to gain a deep understanding and conduct simulations to accurately predict thermal transport at ultra-high temperatures in order to realize technology revolutions. This project addresses a critical issue in thermal transport: state-of-the-art theories significantly underpredict the thermal conductivity of most crystals at room temperature and further worsen as the temperature increases. The goal of this project is to unveil the fundamental thermal transport mechanisms and accurately predict the thermal conductivity of nonmetallic materials from low to ultra-high temperatures. The proposal envisions three major foci: (i) incorporate the fully temperature-dependent interatomic interaction into the predictions and validate the proof-of-concept finding that such effort can generally solve the universal thermal conductivity under-prediction problem at high temperatures; (ii) develop formalisms for five-heat carrier interaction processes, which can be important at high temperatures; (iii) develop a method that can fully predict the photon contribution to thermal transport in solids through accurate prediction of the dielectric function. The project will enable five-heat carrier interaction predictions, which will be potentially transformative because they are intrinsic thermal transport mechanisms in all solids and have been elusive to scientists for decades. It will answer two pressing questions: In general solids, at what temperatures is the five-heat carrier interaction important? At low temperatures, in which systems is the five-heat carrier interaction important? This project will also rigorously predict and validate the thermal radiation contribution to thermal conductivity at high temperatures. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.