Discussion on a general formula of sediment diffusion coefficient and sediment fluctuating intensities in the sediment-laden flow

Abstract

According to the research achievement of velocity fluctuating intensities, the formula of sediment fluctuating intensities is raised analogically and is verified with the experimental data. The results show that the formula structure could preferably conform to the distribution tendency. A general expression about SDC (sediment diffusion coefficient) is deduced to describe the three types of SDC. Meanwhile, a simple-structure SSC (suspended sediment concentration) profile formula is obtained for depicting the situation largest SSC absent from the bottom. The classic field data as well as experimental results of three types SDC and the measured data in the hyper concentration flow are applied to calibrate the SDC profile formula, and the data of flume experiments and pipeline tests are utilized to validate the SSC profile formula. With a discussion of the value range of relevant parameters of the SDC and SSC equations in different water-sediment environments, the conclusion is gained that the parameters in higher concentration flow are relatively steady while the mutative amplitude of the ones in lower concentration is comparative larger.