Publication: Two-dimensional depth-averaged Simulation of Mudflow Propagation With Gate-lifting effects.
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Date
2025-04
Authors
Tan, Jeff Fei
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Abstract
In dam-break experiments with water, the gate-lifting process significantly influences flow propagation. However, in mudflow dam-break experiments, the impact of the gate-lifting effect remains underexplored. This study presents a twodimensional depth-averaged mudflow simulation model using the Constrained Interpolation Profile (CIP) scheme, incorporating the Herschel-Bulkley rheological model to capture mudflow behaviour. One of the objectives is to investigate the gatelifting effect on mudflow propagation. Before analysing mudflow behaviour, the numerical model is first validated for inviscid fluid simulation. The developed model demonstrates its reliability by qualitatively replicating the flow depth profile and
velocity variations of Akoh’s third-order model, validating its capability to accurately simulate inviscid fluid flow. Further validation is conducted for mudflow simulation, where similar propagation results such as matching gradients during the viscous phase produced by both the developed model and Puay’s integral model validate the reliability of the developed model in mudflow simulation. To examine the gate-lifting effect, dam-break mudflow simulations are performed and compared with experimental data from previous research. Simulations revealed that neglecting the gate mechanism led to faster initial flow propagation, but this effect weakened as rheological properties began to dominate the flow behaviour. However, the gate-lifting effect has a permanent impact on flow spreading and the surge profile. Additionally, one of the objectives in this study examines the influence of rheological parameters on mudflow propagation, showing that within the yield stress range of 78-109 Pa and plastic viscosity range of 32.10-75.84 Pa·s⁻ⁿ, higher yield stress and plastic viscosity
result in shorter flow propagation due to increased flow resistance. The results align well with theoretical predictions, indicating that the developed model can reproduce mudflow behaviour across a range of rheological parameters. These findings contribute to a better understanding of mudflow dynamics in dam-break scenarios and enhance numerical modelling method for hazard assessment and mitigation in mudflow-prone regions.