The method of matched asymptotic expansions, which has been used in previous studies of steady natural convection flow, is extended here to transient natural convection flow at high Prandtl number (Pr). Second-order expansion solutions, valid for large Prandtl numbers, are presented for the transient natural convection flow near a vertical surface which undergoes a step change in temperature. T...

In this paper a transient free convection flow around a sphere with variable surface temperature and embedded in a porous medium has been considered. The temperature of the sphere is suddenly raised and subsequently maintained at values that varies with position on surface. The method of asymptotic expansions is applied for small Rayleigh numbers and then a finite-difference scheme is used to s...

facts technology has considerable applications in power systems, such as; improving the steady stateperformance, damping the power system oscillations, controlling the power flow, and etc. statcom is oneof the most important facts devices used in the parallel compensation, enhancing transient stability andetc. since three phase fault is widespread in power systems, in this paper statcom is used...

FACTS technology has considerable applications in power systems, such as; improving the steady stateperformance, damping the power system oscillations, controlling the power flow, and etc. STATCOM is oneof the most important FACTS devices used in the parallel compensation, enhancing transient stability andetc. Since three phase fault is widespread in power systems, in this paper STATCOM is used...

Subcooled flow boiling in multi-microchannels can be used as an efficient thermal management approach in compact electrical devices. Highly subcooled flow boiling of HFE 7100 is studied in two microchannel heat sinks to choose a proper numerical model for simulating boiling flows in microchannels. Results of five different numerical models, including Volume of Fluid (VOF), Eulerian boiling, Eul...

evaluating drainage systems, exploring their strengths and weaknesses, provides a comprehensive perspective to designers and organizers for optimum design and implementation of guidelines for the future. this study was conducted at an experimental site consisting of three plots on a subsurface drainage network under operation in behshahr, a coastal region in northern iran. to evaluate system pe...