Investigation of dam-break induced shock waves impact on a vertical wall

- Impact of dam break flood wave on flume end wall causes wave reflection against the wall.
- A moving negative wave with undulations on free surface towards upstream, occurs.
- Tailwater levels effect on wave breaking, turbulence volume and feature of undulations.
- Stage hydrographs were determined via synchronous video images with virtual wave probe.
- RANS model provides good results in stage hydrographs with conpared to SWE model.

SummaryIn the present study, experimental tests and VOF-based CFD simulations concerning impact of dam-break induced shock waves on a vertical wall at downstream end were investigated. New laboratory experiments were carried out in a rectangular flume with a smooth horizontal wet bed for two different tailwater levels. Image processing was used for flow measurement and time evolutions of water levels were determined effectively by means of synchronous recorded video images of the flow. This study scrutinized formation and travelling of negative wave towards upstream direction, which was resulted from the reflection of flood wave against downstream end wall. In numerical simulation, two distinct approaches available in FLOW-3D were used: Reynolds- averaged Navier-Stokes equations (RANS) with the k-ε turbulence model and the Shallow Water Equations (SWEs). The measured results were then compared with those of numerical simulations and reasonable agreements were achieved. General agreement between laboratory measurements and RANS solution was better than that of SWE.