The National Science Foundation (NSF) awarded a $498,290 Project Grant through its Mathematical and Physical Sciences (CFDA 47.049) federal grant program to North Carolina State University (NC State) for the "MATH-DT: GRADIENT-ENHANCED DEEP GAUSSIAN PROCESSES FOR OPTIMIZATION OF DIFFUSIVE HIGH-SPEED UNSTEADY MIXERS" research project. The project aims to develop advanced mathematical models and a digital twin simulation to optimize the design of rotating detonation combustors coupled with highly diffusive mixers, which hold promise for compact, efficient, and environmentally-friendly energy production systems. The research will leverage a three-pronged approach featuring a gradient-enhanced Bayesian deep Gaussian process surrogate model, a reduced-cost digital twin simulation, and a physical wind tunnel experiment to enable the optimization of these mixer systems. The project period runs from January 1, 2025 through December 31, 2027. No sub-awards are planned under this grant.