Coastal pollutant transport modeling using smoothed particle hydrodynamics with diffusive flux. (December 2020)

• Record Type: Journal Article
• Authors: Liu, Wanying; Hou, Qingzhi; Lian, Jijian; Zhang, Anmin; Dang, Jianwu
• Is Part Of: Advances in water resources. Volume 146(2020)
• Publication Date: 2020-12
• Subjects: Pollutant transport -- Lagrangian particle model -- Advection-diffusion equation -- MTVDLF-Superbee -- SPH; Hydrology -- Periodicals; Hydrodynamics -- Periodicals; Hydraulic engineering -- Periodicals; 551.48
• DOI: 10.1016/j.advwatres.2020.103764
• Languages: English
• ISSNs: 0309-1708

Abstract

Highlights: A Lagrangian particle model based on smoothed particle hydrodynamics is proposed for the simulation of pollutant transport in coastal water. By incorporating the diffusive flux, the model approximates two first-order derivatives instead of the second-order diffusion term directly. The developed model is validated against advection dominated pollutant transport problems with discontinuity, pure advection, grid anisotropy and large deforming flow. Abstract: The Smoothed Particle Hydrodynamics (SPH) method is used in this paper to simulate the transport process of coastal pollutant by solving the two-dimensional (2D) depth averaged advection-diffusion equation in Lagrangian framework. To avoid directly discretizing the second-order derivatives, the diffusion terms are decomposed into two first-order derivatives by introducing the diffusive flux. To verify the proposed Lagrangian particle model, numerical experiments on four typical tests are performed, including the discontinuity, pure advection, grid anisotropy and large deforming flow. The high-resolution Total Variation Diminishing (TVD) scheme - the modified TVD Lax–Friedrichs method with Superbee limiter (MTVDLF-Superbee) - is also implemented for detailed comparison. The simulation results indicated that the present SPH-based model has better performance than MTVDLF-Superbee. In addition, the stability, convergence and efficiency of the proposed model are numerically analyzed. The Lagrangian particle model with diffusive flux gives satisfactory results with big time step and hence allows large Courant number, guaranteeing the computational efficiency.