بررسي آزمايشگاهي عوامل موثر بر ميزان تخليه رسوبات در رسوب شويي تحت فشار

The Experimental investigation of the effects of pressure flushing on flushed sediment through storage reservoir

In the pressure flushing the amount of the flushed sediments depend on many parameters such as water depth in the reservoir, outflow discharge through bottom outlets, kind and particle size of the deposited sediments. In this study the effects of these parameters was investigated. In this research, laboratory experiments were performed to investigate the flushing process during pressure flushing. Therefore a physical model was constructed at Shahid Chamran university, Ahvaz. The overall dimensions of the flume were, 7m long, 1.5in wide and height. The experiments were carried out with 5 outflow discharge, 3 water depths, and 3 size of sediment. In general 45 experiments were carried out. The results of these experiments show that when outlet was opened, sediments near outlet released under the water pressure and a after some minutes a scour cone was developed around the outlet. The results of this study show that for a constant water depth, the increasing of the outflow discharge would cause the scour cone volume and its length was increased. Also the decreasing of the particle sediments has positive effect on the increasing of the scour cone volume and its length. Based on the non-dimensional analysis and statistical analysis with SPSS software, relations as linear multiple regression are offered for determining of the scour cone volume and its length with R2=0.87 and R =0.90, respectively. According to the coefficients of correlation indices, multiple regression models have a high prediction performance.