Laboratory observations on internal solitary wave evolution on steep and inverse uniform slopes

Laboratory experiments were conducted to investigate the evolution of internal solitary waves of depression or elevation type reflecting from steep slope in a stratified two-layer fluid system. Environmental settings considered in these experiments included the upper and lower layer thickness, the difference in interface levels and inclination of uniform slope, etc. Physical phenomenon and dynamic mechanism of wave fluctuations are discussed in the course of wave breaking and evolution on the slope. Based on the experimental results available, criteria governing wave evolutions are proposed for an internal wave of depression or elevation encountering uniform slope from normal to inverse configuration. A mirror-image model is hypothesized to provide a generic description of the physical consequences leading to wave breaking and mixing on a wide range of uniform slopes. In addition, mixing efficiency resulting from wave breaking was found to approach a maximum value of 25% when the characteristic length ratio was around 0.5, with a reduction in efficiency for slopes on either side of this peak. (C) 2006 Elsevier Ltd. All rights reserved.