A study of flow conditions near the substratum in an experimental channel [Translation from: Verhandlungen der Internationalen Vereinigung fur Theoretische und Angewandte Limnologie 18, 718-725, 1972]

In a slow flow, on a smooth uniform substratum, a limited bed allows the existence of currents slow enough for benthic invertebrates. These conditions rarely occur naturally. The investigations carried out in this work aimed, on an intermediary scale, to define the influence of irregularities in the substratum on flow near the bottom. The substrata used were made of glass marbles. The investigations were carried out in a transparent channel of 70 cm in length and a rectangular section 10 x 5 cm. The data was analysed to study the general evolution of flow in terms of average speeds and the appearance of the turbulence near the bottom.

Comparisons of open boundary conditions in a barotropic model of the northern Arabian Sea

These simulations are focused on the sensitivity of the barotropic ocean non-linear model to the various open boundary conditions (OBCs). Different OBCs from gradient to radiation condition are examined to determine the best result and help to choose the most appropriate OBCs. Since the interior points are changing with time both implicit and explicit forms are applied. The simulations showed that the interior flow is sensitive to changes in the OBCs and the results are highly dependent on the bathymetry of the area. When a constant depth (100m) is used, the circulation pattern with all OBCs is same. The best boundary conditions are Orlanski Radiation and its modified form. These boundary conditions produce identical adjustment in velocity and are determined to be satisfactory for both constant depth and actual bathymetry.