Author(s): Manasa Ranjan Behera; K. Murali; V. Sundar
Linked Author(s): Madhu Krishna Murali, Kantharaj Murali
Keywords: Tsunami; Runup; Grid size; Spherical shallow water equation
Abstract: A numerical investigation has been carried out to obtain a suitable grid size (dx) for the near shore discretisation of computational domains for long wave modelling. A two-dimensional domain has been considered in which the flow has been solved by two-dimensional spherical shallow water equations with depth averaged flow variables. The considered domain with very large length and limited width, acting as a channel, has been imposed with open boundary at one end and shelf boundary at the other end. A typical tsunami wave, with initial perturbation of width (B) and height (h), has been simulated in the domain and the runup height (R) at the shelf break end has been computed and compared for different grid sizes. The grid size varying from 1000m to 10m is considered for the landfall height computation and their respective consumed computational time were studied. The initial perturbation width of tsunami (B) has also been taken into account for optimising the grid size. The nondimensional parameter dx/B was optimised by comparing the non-dimensional runup (R/h) and a threshold value of 5.0e-4 was obtained.
Year: 2010