Physical effects in laminar microconvection due to variations in incompressible fluid properties

摘要

In this investigation we report the identification of laminar microconvection physical effects due to the variation of viscosity and thermal-conductivity of liquid. Viscosity variation significantly distorts the axial velocity profile and varies this distortion along the microflow, thereby inducing radial flow due to flow continuity. The resulting induced radial heat convection can be a significant percentage of the axial heat convection, especially in microconvection. Also, axial conduction is induced due to fluid thermal-conductivity variation along the flow. The effect of distorted axial velocity profile and the induced radial flow on microconvection due to fluid viscosity variation are opposite. However, fluid thermal-conductivity variation along and across the flow have the same effect on microconvection. Thus, a deviation in convection due to thermal-conductivity variation exceeds the deviation due to viscosity variation, although the dimensionless temperature sensitivity of viscosity is higher. (c) 2006 American Institute of Physics.