2025 Volume 81 Issue 16 Article ID: 24-16201
Numerical computations that consider more detailed conditions are necessary to predict flood flow phenomenon. The Average Component Acceleration (ACA) method, developed by the authors, enables accelerated analysis by shortening the time scale of discharge hydrographs and adding averaged component terms to the time evolution equation for water depth. In this study, we clarified that the reason of the numerical oscillations appearing in the ACA methods with high acceleration rates is partly due to the riverbed gradient. Additionally, we successfully eliminate oscillations by weighting the averaged component terms. When the ACA method was applied to the GBVC3 method, it represented differences in water levels between left and right banks. Furthermore, the turbulence kinetic energy calculated from the analysis results closely matched that of the original analysis. Thus, the ACA method demonstrates the potential to accelerate analysis while maintaining the accuracy of quasi-three-dimensional analysis methods.
