Computational Fluid Dynamics Simulation of Clearance Effect in High Solid Loading Polydisperse Solid-Liquid Mixing

A high solid loading concentration of solid-liquid mixing was investigated to observe the effect of ratio C, Clearance, and T, diameter tank, with C/T 0.33; C/T 0.25 and C/T 0.17 on local volume of hydrodynamic and spatial distribution of polydisperse solid suspension using CFD, Computational Fluid Dynamics. The 45o pitch blade turbine, diameter 0.5T, with down pumping flow simulation was used to remove solid particle from bottom of the tank. The tank is also equipped with four baffle with the size of 0.1T.. A solid-liquid mixing consists of five fractions of glass beads with equal proportion (X1=X2=X3=X4=X5=0.2X) have 40% wt total solid concentration with liquid fraction is aqueous solution of NaCl. The effect of ratio C/T at impeller speed 612 rpm create a flow pattern in the tank different. Effect ratio C / T also indicated the distribution on solid had a good uniformity index when N≥ Njs, just suspended speed. The highest uniformity was obtained on C/T 0.17. it also made difference power consumption on each geometry with C/T 0.17, 0.25, and 0.33 respectively are 251.18, 238.13, and 270.65watt

Computational fluid dynamics based analysis of a closed thermo-siphon hot water solar system.

One of the alternative sources of energy is solar energy which is available in abundance throughout the world. The energy contained within the solar rays is capable of starting natural convection within closed mechanical systems containing a suitable working fluid. One such system is commonly known as a Thermo-Siphon which transfers solar energy into internal energy of the working fluid, commonly water. In the present study, an attempt has been made towards better understanding of the flow structure within a thermo-siphon by analysing the natural convection phenomenon using Computational Fluid Dynamics techniques. A commercial CFD package has been used to create a virtual domain of the working fluid within the thermo-siphon, operating under no-load condition. The effects of the length to diameter ratio of the pipes connecting the condenser and the evaporator, number of connecting pipes, angle of inclination of the thermo-siphon and the heat flux from the solar rays to the working fluid, on the performance of the thermo-siphon, have been critically analysed in this study. The results depict that the heat flux and the length to diameter ratio of the pipes have significant effects on the performance of a thermo-siphon, whereas, the angle of inclination has negligibly small effect. Furthermore, an increase in the number of connecting pipes increases the temperature of the working fluid by absorbing more solar energy. Hence, CFD can be used as a tool to analyse, design and optimise the performance output of a thermo-siphon with reasonable accuracy

Supersymmetric Fluid Dynamics

Recently Navier-Stokes (NS) equations have been derived from the duality between the black branes and a conformal fluid on the boundary of AdS_5. Nevertheless, the full correspondence has to be established between solutions of supergravity in AdS_5 and supersymmetric field theories on the boundary. That prompts the construction of NS equations for a supersymmetric fluid. In the framework of rigid susy, there are several possibilities and we propose one candidate. We deduce the equations of motion in two ways: both from the divergenless condition on the energy-momentum tensor and by a suitable parametrization of the auxiliary fields. We give the complete component expansion and a very preliminary analysis of the physics of this supersymmetric fluid.Comment: 24 pages, Latex2