浮遊現象に及ぼす粒度組成の影響に関する実験

Abstract

Some experiments on the influence of size frequency distributions of sediments on theirsuspension in water have been carried out by using a small water tank having several oscillatingholed plates like as used by H. Rouse in 1939. The purpose of the experiments is to clarifywhether the method of superposition such as Einstein's one to estimate the concentration ofgraded sediments in suspension is applicable or not in a turbulence field.After some experiments for uniform particles to verify the uniformity of the turbulencefield in the tank and the uniqueness of the suspension phenomena, the distributions of sedimentconcentrations of graded sediment in suspension and size frequency distributions of suspendedloads have been measured in various cases. It is concluded from the comparison betweenthe calculated distributions of sediment concentrations and the experimental results, andfrom the experimental results of coefficients of eddy viscosity that the method of superpositionis not applicable in turbulence fields; therefore, the mechanics of suspension of graded sedi-ments should be established in connection with turbulence spectra.