  In this study, we performed highly resolved large-eddy simulations (LES) to
investigate the influence of variable properties on the forced turbulent
convection in a channel. The constant heat flux boundary condition permits wall
temperature fluctuations and thus induces variations of fluid properties. Since
the effect of viscosity on the flow exhibits $Re_\tau^{-1}$ scaling, we only
considered $Re_\tau = 180$ in the present study. Compared to the flow with
constant properties, results indicate that the variable properties have trivial
effects on the mean velocity and temperature profiles, Reynolds shear stress,
wall-normal heat flux, as well as the small-scale turbulence characteristics.
However, we also observed that the turbulence intensities, low-speed streaks,
burst motions, and budgets for temperature variance and wall-normal heat flux
are modified by the variable properties in a perceptible way. In addition, we
showed that the classic wall scaling is a good choice for flow with small and
moderate variations of fluid properties.
