The experiments discussed in this paper involve the motion of discrete solid particles on a plane slope under spilling breaking wave conditions. Particle Image Velocimetry was used to capture images of seeder particles in water so the motion of the fluid particles and solid particles could be traced. The images produced from the experiments have two phases. Since the behavior of the water and the sediment particles must be studied individually, the two phases of the image must be separated. A series of functions in MATLAB allows the two-phase image to be separated into two images—one containing only the sediment particles and one with the background seeder particles which represent the fluid phase. The ultimate goal of this study was to determine how the sediment particles behave under spilling breaker wave conditions. MATLAB was used to fit a fourth order polynomial to seven data points from which the sediment particle velocities and accelerations could be found. Three situations of interest were investigated: (1) no large-scale turbulence in the field of view, (2) a turbulence burst landing shoreward of a sediment particle, and (3) a turbulence burst occurring seaward of a sediment particle. It was found that regardless of which of the above three situations occurred, the net transport of the sediment particles over one wave cycle was offshore for the spilling breaker case. The intensity and location of the downbursts determined only the magnitude of the net offshore transport.
"Particle Motion On A Plane Slope Under Spilling Breaking Waves,"
The Journal of Undergraduate Research: Vol. 6
, Article 10.
Available at: http://openprairie.sdstate.edu/jur/vol6/iss1/10