A Lagrangian particle model on GPU for contaminant transport in groundwater

To simulate contaminant transport in groundwater, this paper proposes a parallelized Lagrangian particle model using compute unified device architecture (CUDA) on graphics processing unit (GPU) based on smoothed particle hydrodynamics (SPH) method. The solved governing equation is the advection–diffusion equations (ADEs) with retardation factor for given typical flow fields. To solve the inherent particle inconsistency problem of traditional SPH method, the corrective smoothed particle method (CSPM) is applied. The speedup ratio of the parallelized SPH solver for ADEs is analyzed. The consistency and convergence of the proposed model are theoretically analyzed and numerically tested. The reduction of its computational cost and storage requirement is discussed. Numerical examples including one-dimensional (1D) and two-dimensional (2D) cases are simulated, and the results are compared with the analytical solutions and those obtained by the high-resolution monotonic upstream schemes for conservation laws (MUSCL) scheme. To further verify the practicality of the model, two engineering cases of contaminant transport through soil into groundwater are investigated. It is shown that the solutions of the developed model are in good agreement with measured data.