His research interests focus on both fundamental and applied CFD in multi-disciplines. Fundamental CFD research includes estimation of errors and uncertainties using quantitative solution verification and validation (V&V) methods and entropy generation for bypass transitional boundary layers. For V&V, he developed the "factor of safety method" for solution verification that was evaluated as one of the two most accurate uncertainty estimates for monotonically converged numerical solutions. He was invited to give 14 lectures including the keynote lecture on verification and validation in the 13th National Congress on Hydrodynamics & 26th Conference on Hydrodynamics in China. Applied CFD research covers a broad range of disciplines where CFD can be used to improve understanding of flow physics and optimize designs: onshore and offshore wind turbine designs, vehicle aerodynamics, pulmonary ventilation including fluid-structure interaction, ship hydrodynamics, and desalination, etc.