Minimum Requirement for Debris Flow Modelling Using Smoothed Particle Hydrodynamics (SPH)
Indra A. Dinata (a, b*), Imam A. Sadisun (a, b), Prihadi Soemintadiredja (a), and Lambok M. Hutasoit (a)

a) Applied Geology Research Group, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Indonesia
*indraandradinata[at]gmail.com
b) Research Centre for Disaster Mitigation, Institut Teknologi Bandung, Indonesia

Abstract

The debris flow can be modeled using physical and mathematical modelling methods based on rheological property measurements and movement parameters. Some software commonly used for debris flow modelling include Debris2D, Flo-2D, Kanako 2D, RAMMS, Riverflow2D, and TRIGRS. This mentioned software have different analysis methods. The analysis used has a very good part for modeling debris flow. However, there are still parts of the analysis that still have shortcomings in modeling one of the debris flow parameters. The deficiency of the currently developed model (two phase debris flow) is the debris material segregation process. The debris material segregation process is approached by refining the volume changes behavior model in debris flow which erodes river geometry and maybe deposited when flowing.

The numerical simulation which may better to modelling the volume change behavior uses smoothed particle hydrodynamics (SPH) from the momentum and energy equation. The governing equations are continuity and momentum equations in Lagrangian form. The process for solid and liquid phases modeling simultaneously can be assisted by the Coulomb Grain Flow Equation which was developed into the Herschel-Bulkley-Papanastasiou model. The SPH implementation uses DualSPHysics open-source code which can be further developed according to needs with the C++ programming language and compute unified device architecture (CUDA). The lack aspect of SPH model need the most advance processing unit (CPU/GPU) to process it. In this research, the suitable processing unit to modelling debris flow using SPH is NVIDIA GeForce 4090.

Keywords: debris flow, deterministic modelling, smoothed particle hydrodynamics

Topic: Interdisciplinary Earth Science and Technology