Fluidized bed is widely used in chemical processing industries and heat transfer operations because of high heat transfer and mass transfer rates due to intermixing. This work deals with estimation of the force imparted by the bed material on the tube assemblies in a fluidized bed by CFD technique. The gas-solid flow was simulated by means of a multi-fluid Eulerian model incorporating the kinetic theory for solid particles. The pulsating forces were compared to experimental data of Kennedy et al. A good approximation was observed in force exerted over different tubes. However minor differences were observed in interval duration of the peak forces.

The testing of physical turbine models is costly, time consuming and subject to limitations of laboratory setup to meet International Electro technical Commission (IEC) standards. Computational fluid dynamics (CFD) has emerged as a powerful tool for funding numerical solutions of wide range of flow equations whose analytical solutions are not feasible. CFD also minimizes the requirement of model testing. The present work deals with simulation of 3D flow in mixed flow (Francis) turbine passage; i.e., stay vane, guide vane, runner and draft tube using ANSYS CFX 10 software for study of flow pattern within turbine space and computation of various losses and efficiency at different operating regimes. The computed values and variation of performance parameters are found to bear close comparison with experimental results.Key words: Hydraulic turbine; Performance; Computational fluid dynamics; Efficiency; LossesDOI: 10.3126/hn.v7i0.4239Hydro Nepal Journal of Water, Energy and EnvironmentVol. 7, July, 2010Page: 60-64Uploaded date: 31 January, 2011

Hydrodynamic journal bearings are critical power transmission components that are carrying increasingly high loads because of the increasing power density in various machines. Therefore, knowing the true operating conditions of hydrodynamic journal bearings is essential to machine design.Oil film pressure is one of the key operating parameters describing the operating conditions in hydrodynamic journal bearings.Hydrodynamic journal bearings are analyzed by using Computational fluid dynamics (CFD) and fluid structure interaction (FSI) approach in order to find deformation of the bearing. Journal bearing models are to be developed for eccentricity ratios to study the interaction between the fluid and elastic behaviour of the bearing.The deformations of the bearing is significant and should be considered in order to predict accurate performance of the hydrodynamic journal bearings.The work focused onto the modeling of journal bearing by using pro-e for different eccentricity ratios and similations are carried out to determine the pressure,stress and deformation of plain journal bearing by CFD fluid structure interaction approach. It is observed that CFD-FSI method provides a useful platform to study the combined effect of hydrodynamics and elastic behaviour of the bearing. It is observed that the deformations of the bearing are significant and should be considered in order to predict accurate performance of the hydrodynamic journal bearings.