Laboratory study of frazil distribution in a flow

Abstract

Laboratory experiments were conducted in a circular flume to study the formation, flocculation, and distribution of frazil in a turbulent flow from a Lagrangian frame of reference. The evolution of frazil was studied with video taping and frazil concentrations were measured at multiple points under different hydrothermal conditions. The experiments showed that the average vertical distribution of frazil could be approximated with a functional relationship of the error function type. The empirical equation contains three parameters, which specify the maximum concentration gradient of frazil, the position where it takes place, and the depth gap over which significant changes in frazil concentration occur. These parameters were found to be well-defined functions of the total frazil content in the water column, the flow Reynolds number, and the relative boundary roughness. Frazil accumulated mainly within a thin surface layer. Continued production of frazil contributed more to a higher concentration than a thicker surface layer. Key words: frazil, vertical distribution, laboratory experiments.