Journal of the Japan Society of Erosion Control Engineering, Vol.55,No.6,p.40-51,2003

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Numerical simulation and similarity of debris flow

Kuniaki MIYAMOTO, Takahiro ITOH

Abstract

Numerical simulation and hydraulic model test are conducted to estimate and evaluate the phenomena of debris flows such as inundation process and the effect of countermeasure facilities. These two methods are based on different principle. Therefore we wonder that they may not give same results. This leads us to consider the similarity of numerical simulation results and Froude similarity of debris flow. We discuss the similarity of debris flow based on a constitutive equation for a debris flow simulation, and examine Froude similarity of typical examples of numerical simulation results in this paper. We found, as results, 1) The Reynolds similarity of the debris flow is explained as same as Froude similarity. 2) When we scale the finite differential distance so as to match the model scale and give the finite differential time according to Froude similarity, Courant Number in a calculation at each step is the same as one in another scale calculation at the same step.

Key words:hydraulic model test, numerical simulation, debris flow, similarity