Research on the numerical model for the routing of viscous debris flow considering the interface

Abstract

Based on the interface theory, taking the corresponding surface of the yielding depth of debris flows as the interface, the viscous debris flows can be divided into the ideal fluid and the Bingham fluid. Thus, a vertical layered numerical model and its relative algorithm are developed to simulate the routing of viscous debris flows. The model is based on the motion feature of the debris and takes the velocity differences of debris flows in different layers into account. Therefore, it reasonably describes the routing mechanism and its impact on the morphology of debris flow due to the flow velocity. In addition, the model fully considers the phenomena of ‘tongue-like’ and ‘debris flow head’ of actual viscous debris flows and thus accurately depicts the motion state of the debris flow during the routing. A series of model experiments are adopted to verify the proposed numerical model and the algorithm. Compared with the measured data, the relative errors of the inundation areas and maximum accumulation thicknesses are within ±5%. Then, the comparison between the proposed model and other models further testifies the rationality of the proposed model.

Keywords:

• Bingham fluid
• interface
• alternating direction implicit method
• finite volume method

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the National Key Research and Development Program of China (Grant No. 2017YFC0804605); the National Natural Science Foundation of China (NSFC) (Grant No. 51539006); The financial support from Nanjing Hydraulic Research Institute (NHRI) (Grant No. Y118013).