Turbulence in Uniform Openchannel Flow Second Report:Turbulent Structures in Uniform Openchannel Flow varing with Bed Roughness

摘要

In contrast to large quantity of data available from the measurement of turbulence in air there is a significant lack of information on the detailed structure of turbulence in water. Especially, few knowledge on open channel turbulent flow which has non-isotropic and homogeneous turbulent structures are clarified. The objective of this paper is to present some results obtained in uniform openchannel turbulent flow･varing with bed roughness. By neans of computer analysis of the lengitudinal component turbulent velocity measured by hot film flowmeter, several turbulent statistical characteristics which are important elements to explain the structure of turbulence such as probability distribution, auto-correlation co-efficient, one-dimensional spectral function, macro-scale, dissipation-scale, energy dissipation, are caliculated.