Modelling free surface incompressible flow around thin vertical wall incorporating hydrodynamic pressure on sigma-coordinate
Submerged thin walls are extreme case of submerged rectangular blocks, and could be used for many purposes at coastal zones or rivers, e.g.protecting tsunami.To understand flow characteristics including flow and pressure fields around a specific submerged thin wall a new algorithm in a numerical model, CST3D, is developed which includes computation of hydrodynamic pressure with solution procedure of a new divergence equation on moving sigma-coordinate.Sigma-coordinate is adequate for simulation of subcritical flow over mild-sloped beds.However sigma-coordinate is quite poor to simulate flows around sharp structures on the bed.Most sigma-coordinate approaches have adopted assumption of hydrostatic pressure.A few previous trials include hydrodynamic pressure by solving the Poisson equation on pressure.The other solution algorithm to treat hydrodynamic pressure was the divergence removing method, SOLA, developed by Los Alamos Lab., which is valid for fixed grid approaches only.The SOLA is modified here by including the flow unsteadiness within the divergence equation, so that accurate divergence is computed at every computational time step on sigma-coordinate.Computed flow field shows reasonable flow pattern including structure-scale vortices.Computed vorticity field reveals that the downstream vorticity is much stronger than the upstream one.The model was verified to laboratory experiments at a 2DV flume.Time-average flow vectors were measured by using one-dimensional electro-magnetic velocimeter.Computed horizontal velocity components of flow agree well with the measured ones within 6 cm/s error at5 sections.
submerged thin wall CST3D hydrodynamic pressure sigma-coordinate sola vorticity
H.Kim D.H.Hwang S.W.Baek H.J.Yoo C.Jang J.Jin
Department of Civil and Environmental Engineering, Kookmin University, Seoul, Korea Geosystem Research Corporation, Busan, Korea Korean Intellectual Property Office, Daejeon, Korea Korea Institute of Ocean Science and Technology (KIOST), Ansan, Korea
国际会议
the International Conference Vibroengineering-2014
贵阳
英文
318-323
2014-11-07（万方平台首次上网日期，不代表论文的发表时间）