Narrow Results

A new numerical multiphase model is presented to study wave propagation over arbitrary shaped submerged obstacles. The high order space accurate weighted essentially non-oscillatory (WENO) method is adopted along with relatively coarse Cartesian uniform grids. Viscosity effects are included and the free surface is tracked using the level set method. The model is validated via application to solitary and progressive wave motion over rectangular, trapezoidal and semicircular obstacles. The complex flow field features induced near a large sized obstacle, including separation vortices and large free surface deformations, are accurately reproduced. Compared to other relatively complicated models, the present model is efficient and produces enhanced results.

In this paper we address the problem of producing an enlarged picture from a given digital image. We propose a zooming technique based on ENO and WENO schemes that are high order accurate finite difference schemes designed for problems with piecewise smooth solutions containing discontinuities. ENO and WENO schemes have been quite successful in applications, especially for problems containing both shocks and complicated smooth solution structures, such as compressible turbulence simulations and aeroacoustics. The algorithm works both on monochromatic images and RGB color pictures. Our experiments show that the proposed method is better than classical simple zooming techniques (e.g. pixel replication, bilinear interpolation). Moreover our algorithm is competitive both for quality and efficiency with bicubic interpolation.