彎曲水路における乱れの特性について

Abstract

This paper describes the turbulence characteristies of curved flows on the basis ofthe results of velocity measurements by a small propeller type current-meter. Themeasurements were conducted in two kinds of 1800 curved open channels with 50 cm inwidth and different central radii of 50cm and 150cm each other under conditions ofsupercritical flows. The turbulence characteristics obtained from the statistical analysisof longitudinal velocity component are summarized as follows.The intensity and the length scale of turbulence decrease in the curved and thedownstream straight reaches except the outer part of the inlet region of the curved reachwith the smaller central radius. In the outer part of the region, the turbulence intensityincrease, but the r. m. a. of the velocity fluctuation are no more than that of the upperstraight reach and the turbulence scale also decrease. The decrease of turbulence inte-nsity and scale is due to the decrease of energy spectral density in the lower frequencyrange.