Unsteady flow simulation using the curvilinear multiple-relaxation-time lattice Boltzmann method: Danube River case study

Abstract

© 2019, © 2019 International Association for Hydro-Environment Engineering and Research. In order to introduce the lattice Boltzmann method as a competitive approach compared to traditionally based mathematical models when river and coastal hydraulics are considered, the innovative curvilinear multi-relaxation-time lattice Boltzmann method for solving 2D flow equations transformed in curvilinear coordinate system is utilized. The curvilinear approach implemented in the multi-relaxation-time lattice Boltzmann method is tested on a geometrically simple non-prismatic channel and on a section of the Danube River. Steady flow tangential velocity measurements are used in case of the channel model verification, while in case of the Danube unsteady flow is examined. Corresponding velocity and water level measurements acquired during a period of five days are used for calibration and verification of the Danube model, while an alternative mathematical model based on the traditional fractional-step approach has been exploited for comparison. The presented results confirm the aptness of the proposed model to simulate flow in natural water bodies effectively and accurately, therefore it is fully competitive with the classic computational fluid dynamics models.