Physical effects in pure continuum-based laminar micro-convection due to variation of gas properties

摘要

The governing continuum-based conservation equations for laminar 2D (with axisymmetry) convective micro-tube-flow of gas are numerically solved. These equations comprehensively incorporate the physical effects of variations of gas density with pressure and temperature, and gas viscosity and thermal conductivity with temperature. Their non-dimensionalization reveals the significance of variations in gas properties in convective micro-flows, and the role of the dimensionless groups, especially the Brinkman number/s. Even at very low Mach numbers, gas density variation is induced due to the significance of density-temperature sensitivity of gas, in micro-convection. The induced radial flow due to gas density and viscosity variations are numerically captured and results are generated considering different combinations of variable properties. Results indicate that laminar micro-convection characteristics are significantly affected in both quality and quantity, by physical effects induced by variations in gas properties.