A study on free convective flow through porous medium

Abstract

A substance that flows is called as fluid. Fluids are treated as continuous media newlineand their motion and state generally specified in terms of the velocity, pressure, and newlinedensity. All liquid and gaseous substances are considered to be fluids. Water, oil, and newlineothers are very important in our day-to-day life as they are used for generation of newlineelectricity in hydroelectric power plants and thermal power plants, water is also used newlineas the coolant in nuclear power plants, oil is used for the lubrication of automobiles newlineetc. In fluid dynamics, the study of individual molecules is neither necessary nor newlineappropriate for the mathematical models. Therefore, we consider the microscopic newlinebehavior of fluid by supposing it to be continuously distributed in a given space. This newlineassumption is known as the continuum hypothesis. A fluid is said to be viscous or real newlinewhen the normal as well as shearing stresses exist. On the contrary, a fluid is said to newlinebe inviscid when it does not exert any shearing stress, whether at rest or in motion. newlineThe tangential or frictional forces in the viscous fluids are concerned with a quality newlinewhich is called the viscosity of the fluid. Fluid flows obey the laws of conservation of newlinemass, momentum, the thermal energy, and the concentration. Heat transfer is energy newlinetransfer due to a temperature difference between the system and its surroundings. The newlinemost efficient way of transferring heat in fluids is by convection (free, forced and newlinemixed convection). Also, mass transfer is acquired as the transfer of matter by newlinecharacteristic of species concentration variance in a system. The variance in the newlineconcentration provides a driving force for the transfer of mass. Mass transfer always newlinehappens in the direction of reducing concentration gradient. newline