FREE-SURFACE SYNTHETIC SCHLIEREN IMPLEMENTATION ON A WAVE FLUME

Many applications of fluid mechanics involve the presence of interfaces between different fluids. In particular, the dynamics of the water-air free surface is of interest. The most used instruments to measure the height of a wave are the capacitive and resistive gauges. This type of instrument measures the water free surface elevation at a given location and is easy to implement in flumes or tanks. These probes provide measurements at a single point and must be used in line or array configuration to access spatial information. However, this type of instrument is intrusive and can significantly affect the surface, precluding the measurement of smaller scales, such as reflection of waves. Free Surface Synthetic Schlieren (FS-SS) is within the latter, developed by Moisy et al., (2009) and draws attention as no sophisticated equipment is required to reconstruct the free surface.