An Experimental Investigation of the Rainfall on the Turbulence Properties of Overland Flow.

摘要

The principal turbulence characteristics of two-dimensional shallow water flow on a smooth boundary with and without rainfall were studied. The mean and fluctuating components of the longitudinal and vertical velocities,and the corresponding Reynolds stress were measured through the depth of the flow and the mean and fluctuating components of the bottom shear stress were obtained by means of a split hot film sensor and a shear stress sensor respectively. The flow conditions investigated were for a base flow of 546cc/sec without rainfall per foot of width at a depth of 0.678cm which corresponded to a Reynolds number of 7700. Rains falling at the rate of 12.7and 25.4cm/hr on the same base flow were used to estimate the degree of disturbance caused by the rainfall on the internal mechanism of the turbulent flow. The spectral density estimates and autocorrelation functions for each of the shear stresses and of the velocities are calculated and presented.