Effect of Wave and Current Interaction on Flow Hydrodynamics Around a Pier

The waves and currents can frequently be observed together near the coastal region such as estuaries. The presence of wave modifies the flow around the structures like bridge pier near the sea. A clear understanding of turbulent flow filed in such conditions will be very much helpful in the economical and optimal design of the pier. This study experimentally invested the effect of superposition of wave in the direction of current on the flow hydrodynamics around the vertical circular pier on the flat rigid bed. The experiments were conducted in a rectangular laboratory flume. The wave of 0.5 Hz frequency was imposed in the direction of current. The velocity was recorded using Particle Image Velocimetry (PIV). Turbulence characteristics such as mean velocity, intermittency factor with turbulent kinetic energy (TKE) and Reynolds shear stress (RSS) are investigated. The result showed that superposition of wave in the direction of current disturbed the mean velocity distribution on the plane bed and increased the turbulence strength measured in terms of TKE and RSS around the pier.