An experimental and numerical study of the influence of viscosity on the behavior of dam-break flow

International audienceIn this paper, experimental and numerical methods are presented to investigate the dam-break flow in a horizontal rectangular section flume. In the experimental part of the research, different configurations have been tested: dry flume and the presence of shallow ambient water downstream with varied depth. In addition, experiments with viscosity changes in the fluid have been conducted. Numerically, the volume of the fluid method associated with the shear-stress transport turbulence model was used to examine the dam-break flow dynamics. Based on a review of analytical models in the literature, formulas for free water surfaces and propagation fronts were detailed. Qualitatively, various experimental snapshots of free water surfaces were obtained from the digitized images and compared with numerical predictions. Typical jet-like and mushroom-like formations have been observed. Experimental free surface profiles have been plotted against analytical and numerical results for different flow stages. The simulation of high-viscous fluid was conducted to emphasize the role of viscosity in negative wavefront velocity. By the comparison of the dam-break front locations from analytical, experimental, and numerical data, the effects of viscosity on the dam-break flow have been examined. In line with this, the influence of ambient water depth on the front propagation's average velocity has been investigated. Finally, the air bubble characteristics, such as area, shape, and lifetime under the effects of fluid viscosity and surface tension, have been explored