開水路流れにおける乱れの空間構造について(3)

Abstract

The time-space structure of the turbulence field in a two-dimensional free surface shear flow wastreated by means of the technique of time-space correlation coefficient, with and without filtering, for the longitudinal component of turbulent velocity.The characteristics of time-space correlation coefficient of filtered turbulent velocity are describ-ed by the characteristies of auto- and optimum-correlation coefficients and optimum lag-times atwhich the time-space correlation coefficients reach the maximum values. Furthermore, the charac-teristics of auto-correlation coefficient of filtered turbulent velocity are described by the continuationtime which represents the damping characteristins of the auto-correlation coefficient, and that ofoptimum-correlation coefficient are described by its integral scale.Turbulence measurement were carried out in a laboratory channel using two hot-film flowmetersto investigate the characteristics of the tinse-space structure of the turbulence field, and some in-teresting results about the continuation time, optimum integral scales and optimum lag-times, inlongitudinal, lateral and vertical derections, were obtained.