Experimental Study on Backflow Patterns Induced by a Bilateral Groin Pair with Different Spacing

Groins are one of the popular manmade structures to modify hydraulic flow and sediment response in river training. The spacing between groins is a critical consideration balance channel-depth cost construction, which generally determined by backflow formed downstream from groins. A series experiments were conducted using Particle Image Velocimetry (PIV) observe influence groin on pattern two bilateral has significant effect behavior large-scale recirculation cell behind magnitude wake induced was similar that another other side, but direction opposite. spanwise velocity near tip dictates zone width due strong links contraction ratio channel cross-sections Based previous studies present experimental results, quantitative empirical relationships proposed calculate length alternately placed at different along riverbanks. This study provides better understanding robust formula assess extent alternate identify optimum array configuration.