DOI: 10.1615/TSFP4
LARGE-EDDY SIMULATION OF STRAIGHT COMPOUND OPEN-CHANNEL FLOWS
ABSTRAKT
We perform large-eddy simulations of incompressible fully developed turbulent flow in a straight open channel with one flood plain using a dynamic two-parameter model, for depth ratios Dr (≡ h/H) equal to 1/2 and 1/4. The Reynolds numbers based on the hydraulic radius and bulk mean velocity, Rem, are 5470 (for Dr = 1/2) and 4670 (for Dr = 1/4). Particular emphasis is placed on a case of low depth ratio; Dr = 1/4, where interaction between the main channel and the flood plain is significant and is therefore of practical interest. Overall, the computational results agree quite well with laboratory measurements by Tominaga and Nezu [J. Hydr. Engrg. ASCE 117(1991) 21] in spite of difference in their Reynolds numbers and show that the LES code using a sophisticated SGS model is a promising tool for natural river predictions.