Скачать или смотреть Open channel flow over a step

This is an animation from the book, "Fundamentals of Open Channel Flow", by author Glenn E. Moglen, published by the CRC Press (2015). The animation shows an upstream subcritical flow as it encounters an upward step. The top subplot shows a side view of the channel and water surface. The lower subplot shows the E-y diagram that applies to the illustrated flow. As the animation evolves, the top plot shows a growing step height and the water surface dipping down at the step. The lower subplot shows the initial energy and the energy over the step that is reduced by the step height “dz”. When the step height is great enough that the initial upstream energy is insufficient to pass the entire discharge, a choke results and the animation shows the steady-state result of the flow backing up upstream of the step and dashed lines in the water surface downstream of the step indicate that the downstream condition after the step may be either subcritical or supercritical. This is also reflected on the E-y diagram by the diamond points. Color codes are as follows: blue is subcritical, magenta is supercritical, cyan is critical. Green indicated initially specified depth (a subcritical depth).
o Conditions modeled: Q=100 ft3/s, initial depth is 2.8 ft, channel width is 10 feet. Step height increases from 0 ft to 1.77 ft. The flume is frictionless and rectangular in cross-section.