- Wave interactions with a fixed rectangular structure were investigated experimentally using particle image velocimetry (PIV) to simulate the condition of a barge in a beam sea. The structure was mounted in a two-dimensional wave tank while regular waves were used. No overtopping occurred on the deck. Two-dimensional spatial velocity maps on both sides of the structure were measured at eight different phases. Phase average was used to extract the mean flow and turbulence property from the repeated instantaneous PIV velocity measurements. The mean velocity field was demonstrated along with the generation and evolution of vortices and turbulent kinetic energy on both sides of the structure. Each term in the turbulent kinetic energy budget was measured or estimated and the balance was discussed. Clear differences between the flow pattern and the turbulent structure at the two sides were also illustrated. 2004 Elsevier Ltd. All rights reserved.