Non-linear turbulence models for multiphase recirculating free-surface flow over stepped spillways

作者：Tongkratoke Amarin; Chinnarasri Chaiyuth; Pornprommin Adichai; Dechaumphai Pramote; Juntasaro Varangrat^*

来源：International Journal of Computational Fluid Dynamics, 2009, 23(5): 401-409.

DOI：10.1080/10618560902886882

• non-linear turbulence model
• large eddy simulation
• multiphase flow
• recirculating flow
• turbulent flow
• free-surface flow
• stepped spillway

The flow over a stepped spillway is free surface, multiphase and turbulent. Moreover, a recirculation region occurs at each step of the spillway. The flow characteristic is hence complicated and difficult to predict. In previous work on stepped spillways (Chen et al. Journal of Hydraulic Engineering, ASCE, 128 (7), 683-688 and Xiangju et al. Science in China Series E: Technological Sciences, 49 (3), 674-684), only the linear turbulence model was applied which gave low accuracy. Furthermore, there are still no optimised model constants for this kind of flow. The present work therefore aims to apply the large eddy simulation (LES), the non-linear and the modified non-linear turbulence models to simulate the flow over the spillways with various slopes and step heights. It is found that the modified model is able to predict the flow close to the LES but requires less computational time by a factor of up to 4. Moreover, the modified model gives higher accuracy than the LES for the cases of the spillways with higher slopes and step heights.

• 出版日期2009