Sediment transport in pure acceleration-skewed oscillatory sheet flow  

作　　者：Xin Chen Fu-jun Wang Gen-fa Chen Liu-chao Qiu 陈鑫;王福军;陈根发;邱流潮

机构地区：[1]College of Water Resources and Civil Engineering, China Agricultural University [2]Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University [3]China Institute of Water Resources and Hydropower Research

出　　处：《Journal of Hydrodynamics》2018年第6期1045-1054,共10页水动力学研究与进展B辑（英文版）

基　　金：Project supported by the National Naturel Science Foundation of China(Grant Nos.51836010,51609244);the National Science-Technology Support Plan of China(Grant No.2015BAD20B01)

摘　　要：In the present study, an analytical concept model is built, using a two-phase model for the sediment transport in a pure acceleration-skewed oscillatory sheet flow. The analytical model is based on the asymmetric wave theory, the irregular boundary layer theory and the exponential concentration distribution theory, to be used for analyzing the phase lag and the boundary layer development related to the acceleration skewness. The two-phase model is applied for the calculations of the instantaneous erosion depth, the sediment flux, the boundary layer thickness and the sediment transport rate, as well as the differences between the positive acceleration stage and the negative acceleration stage caused by the acceleration skewness, as very important in the net current and sediment transport. The effects of the sediment diameter and the phase lag are explained by a comparison with the instantaneous type empirical formula, as is closely related to the acceleration skewness. With the analytical concept model and the two-phase model, the generation of the net sediment transport in the pure acceleration-skewed flows is clearly explained. The phase lag effect is important for the instantaneous sediment transport in the pure acceleration-skewed flow, whereas the boundary layer development difference between the positive acceleration stage and the negative acceleration stage plays a major role in the determination of the net sediment transport.In the present study, an analytical concept model is built, using a two-phase model for the sediment transport in a pure acceleration-skewed oscillatory sheet flow. The analytical model is based on the asymmetric wave theory, the irregular boundary layer theory and the exponential concentration distribution theory, to be used for analyzing the phase lag and the boundary layer development related to the acceleration skewness. The two-phase model is applied for the calculations of the instantaneous erosion depth, the sediment flux, the boundary layer thickness and the sediment transport rate, as well as the differences between the positive acceleration stage and the negative acceleration stage caused by the acceleration skewness, as very important in the net current and sediment transport. The effects of the sediment diameter and the phase lag are explained by a comparison with the instantaneous type empirical formula, as is closely related to the acceleration skewness. With the analytical concept model and the two-phase model, the generation of the net sediment transport in the pure acceleration-skewed flows is clearly explained. The phase lag effect is important for the instantaneous sediment transport in the pure acceleration-skewed flow, whereas the boundary layer development difference between the positive acceleration stage and the negative acceleration stage plays a major role in the determination of the net sediment transport.

关 键 词：Acceleration skewness analytical concept model boundary layer thickness two-phase model sediment transport rate 

分 类 号：O3[理学—力学]