In this research, effect of nanoparticles dimeter on free convection of aluminum oxide-water was investigated in a cavity by single phase and two phase models. The range of Rayleigh number is considered 105-107 in volume fractions of 0.01 to 0.03 for nanoparticles with various diameters (25, 33, 50 and 100 nm). Given that the two phase nature of nanofluids, necessity of modeling by this method ...

rayleigh-taylor (rt) instability has a growing importance in many fields including aircraft industry and astrophysics. the development and the growth of rt instability were investigated using sinusoidal disturbances with different wavelength at the interface of two fluids. numerical simulations were performed by solving navier-stokes unsteady equations with the vof formulation. results of the 2...

a two dimensional finite difference lattice boltzmann method (fdlbm) for computing single phase flow problems is developed here. temporal term is discretized with low dissipation-low dispersion. discretization of convective term is implemented with third order upwind method. it will be explained governing equations and numerical method. methodology of imposing boundary conditions in fdlbm is de...

In some case of laboratory and industrial applications, various kind of measurement instruments must be placed in a conduit, in which multiphase fluid flows. Vortex shedding for any immersed body in flow field is created with a frequency, which according to flow conditions such as flow rates, geometry of body, etc. may be constant or variable. Failure may happen, if this frequency is close to o...

We report a three-phase bone scintigraphy for the diagnosis of a peripheral bone lesion caused by systemic sarcoidosis. A 32-year-old man with suspected osteomyelitis of the right forefinger underwent three-phase bone scintigraphy with Tc-99m hydroxymethylene diphosphonate (HMDP) and single-photon emission computed tomography/computed tomography (SPECT/CT). The lesion was rich in blood flow acc...

in this paper, a new approach is proposed for the optimum design of single-phase induction motor. by using the classical design equations and the evolutionary algorithms such as genetic algorithms (ga), particle swarm optimization (pso) and modified particle swarm optimization (mpso), a single phase induction motor (spim) was designed with the maximum efficiency. the finite element method (fem)...

This paper proposes a Flexible Power Electronic Transformer (FPET) for the application in the micro-grids. The low frequency transformer is usually used at the Point of Common Coupling (PCC) to connect the low voltage grid and utility network to each other. The conventional 50Hz transformer results in enhanced low voltage-grid power management system during grid-connected operation. In this pap...