Relationship between surface velocity divergence and turbulence microscale in open-channel flows with submerged strip roughness

7th International Symposium on Gas Transfer at Water Surfaces

Okamoto, T.^1 ; Sanjou, M.^1 ; Nezu, I.^1

Department of Civil and Earth Resources Engineering, Kyoto University, Kyoto, Japan^1

关键词: Controlled laboratories;    Dissipation rates;    Empirical model;    Physical modelling;    Surface velocity;    Turbulence measurements;    Turbulent kinetic energy;    Water discharges;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/35/1/012015/pdf
DOI  :  10.1088/1755-1315/35/1/012015

来源: IOP

【 摘 要 】

The present study investigates the effects of strip roughness on surface velocity divergence (SD) to develop physical modelling of gas transfer mechanisms in natural rivers. Particularly, turbulence measurements were conducted by PIV in a computer-controlled laboratory flume with varying water discharge and roughness spacing systematically, in order to obtain the space and time distributions of surface velocity divergence, turbulent kinetic energy and dissipation rate on the horizontal plane. Finally, a new empirical model for the surface velocity divergence was proposed considering turbulence microscales.