Particle image velocimetry measurements within a laboratory-generated swash zone

摘要: A particle image velocimetry (PIV) technique is used to make vertically resolved two-dimensional measurements in swash zone flows, which are notoriously recalcitrant quantitative measurement. The PIV implementation directs the light sheet into measurement region from beneath beach thus avoiding issues of free surface diffraction effects. Fluorescent particles and an optical filter ensure that only particles, not bubbles or anomalies, imaged. spatially temporally velocity fields measured a plunging spilling wave-driven investigate boundary layer structure mean turbulent quantities as well phase evolution bed shear stress, near-bed kinetic energy, dissipation. Results suggest vertical wave forced zones similar. uprush dominated by bore-generated bore-advected turbulence, evolves analogously grid while downrush ultimately generated compares with classic flat plate theory.