Numerical test of scale relations for modelling coastal sandbar migration and inspiration to physical model design  

作　　者：Yuan Li Chi Zhang Shan-hang Chi Yun-han Yang Jian Shi Ti-ti Sui 

机构地区：[1]State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210024,China [2]College of Harbour,Coastal and Offshore Engineering,Hohai University,Nanjing 210024,China [3]State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai 200241,China

出　　处：《Journal of Hydrodynamics》2022年第4期700-711,共12页水动力学研究与进展B辑（英文版）

基　　金：the National Natural Science Foundation ofChina(Grant Nos.41930538,51879096and51909076);the Open Research Fund of State Key Laboratory of Estuarine and Coastal Research,East China Normal University(Grant No.SKLEC-KF202203);the China Postdoctoral Science Foundation(Grant No.2022M711023);the Fundamental Research Funds for the Central Universities(Grant Nos.B220201040,B220203004);the Jiangsu Funding Program for Excellent Postdoctoral Talent.

摘　　要：Physical model experiments on sandbar migration are widely conducted in the wave flume to reveal its hydro-sediment dynamic mechanisms.Selecting an appropriate scale relation is an important part of designing a laboratory experiment.However,evaluating the scale effect is complicated since it is impractical to design wave flume experiments based on strict geometry scales derived from the prototype beach or other laboratory beaches.Here,a process-based numerical model is used to test the Dean and Shields similitudes by comparing sandbar migration and sediment transport in different undistorted model scales using natural sediments.The numerical model provides excellent predictions for both offshore sandbar migration on a real-world beach and onshore sandbar migration in the wave flume.Consistent with previous studies,sandbar offshore migration and suspended sediment transport are similar when the Dean similitude is fulfilled.Sandbar onshore migration and bedload transport can be well reproduced only if the Shields similitude is achieved.Although previous laboratory experiments of sandbar migration generally used the Dean similitude,it is found that the Shields similitude is effective and indispensable for modelling sandbar onshore migration,which will be underestimated if the Dean similitude is only considered.Each scale relation cannot be used simultaneously for modelling both onshore and offshore sandbar migration in physical models.

关 键 词：Coastal sandbar migration sediment transport scale relations numerical modelling 

分 类 号：P641[天文地球—地质矿产勘探]