Narrow Results

The present study carries out the comparison of the water level associated with the numerical methods: Finite Difference Method (FDM) and Finite Volume Method (FVM) and the simulation considered on the present climate condition along the coast of Bangladesh. The governing equations of the first model are discretized through FDM and solved by a conditionally stable semi implicit manner on an Arakawa C-grid system. For the second model, α-coordinate is used for the irrational bottom slope representation and the mesh grid of the study domain is generated by the unstructured triangular cells. The feasible study domain with coast and island boundaries are approximated through proper stair steps for the FDM and the unstructured mesh representation for FVM. A one-way nested scheme technique is applied to the first model to include coastal intricacies as well as to preserve computational cost. Both the models are applied to extrapolate sea-surface elevation associated with the catastrophic cyclone 1991(BOB 01) along the seashore of Bangladesh. The simulation results from both the models are statistically copacetic and make a good acquiescent with some observed and reported data. In the statistical viewpoint, both the method has a good acceptance in storm surge simulation, but this study ensures the strong positive reconciliation with observed data and FVM simulation data. In Bangladesh region, it will be wise decision to use Finite Volume Methods for simulating the storm surge.

Numerical simulation of thermal stress during casting solidification process can predict crack, residual stress concentration, deformation. Though stress simulation involves too many complex problems such as numerical model, mechanical boundary condition and high thermo-mechanical parameters, it still retains as a difficult hotspot of macro-simulation of casting nowadays. Based on finite difference method (FDM), a 3D FDM/FDM numerical simulation system for temperature and stress analysis during casting solidification process was developed. To verify the system, a standard stress frame model and a practical casting were simulated. Pouring experiments have been carried out in the laboratory. The results of simulation coincided with those obtained from experiment and practical results. When adopting FDM to calculate casting thermal stress, thermal analysis and stress analysis can use the same FD model, which can avoid matching between different models and reduce the errors of temperature load transferring. It makes the simulation of fluid-flow, temperature and stress unify into one model.