Sharif Digital Repository

In this study, a three-dimensional mathematical model, based on a nonuniform droplet concentration distribution, has been developed to simulate gas absorption in a venturi scrubber. The mass transfer process was illustrated by assuming the liquid phase as a combination of droplets and film. The flow, just as the annular two-phase flow, includes a flow of liquid film layer on the walls and a flow of gas and liquid drops in the core. Peclet number was determined using experimental data reported by Viswanathan et al. (1984) for distribution of droplets across the cross section of the scrubber. The mathematical model for gas absorption was justified by comparing the theoretical predictions with... 

In this work, thermo-mechanical behavior of an aluminum alloy during gas tungsten arc welding (GTAW) is studied using a three-dimensional mathematical model. The model can be employed to determine residual stresses and their distribution after the welding operation. The effects of the strain hardening and the temperature dependency of material properties have also been considered in the calculations. Model validation has been performed using experimental measurements of residual stress by means of hole-drilling technique. The measurements have been carried out at the heat affected zone (HAZ) and base metal next to the welding line. In addition, microstructural observations have been made to...