Transient Laminar Convection Induced by a Line Heat Source: A Numerical Study with Primitive Variables

The present work is addressed to the numerical study of transient laminar natural convectionin an open space and induced by a line heat source. the governing equations, full navierstokesand energy equations with primitive variables, are discretized in a staggered grid by acontrol volume approach. the equations for the fluid and solid (line heat source) phases aresolved simultaneously using a segregated technique. some of the physical and thermo-physicalproperties of the fluid (air), such as density, thermal conductivity and viscosity, were consideredto vary with temperature. the results show that the energy equation reaches the steady statecondition more rapidly than the momentum equations. hence, at that time, the distribution oftemperature does not show any change within the accuracy of the solution, while the distributionof the velocity still varies. the steady-state results obtained via the time-marching solution showgood agreement with the published steady-state, self-similar results in the vicinity of the centerlineof the plume. also, the steady-state streamlines compare well with the published experimentalresu its.