Ocean waves contain tremendous energy potential. Wave power devices, which extract energy directly from the surface motion of ocean waves, have received considerable attention in both academic and industrial societies in the past few decades. There are multiple different technologies used for wave energy, including absorbers, attenuators, oscillation water columns, overtopping and inverted-pendulum devices. The operation of Wave Energy Converters (WECs) in real ocean environments involves a myriad of complex wave and fluid-structure interaction (FSI) phenomena, including nonlinear and steep waves, wave breaking, flow separation, vortex shedding, and turbulent wake. In our group, we use the high-fidelity computational fluid dynamics (CFD) tool to model and study the WECs.