Abstract:
Thermal mixing behavior of shear-thinning fluids with the specified heat flux boundary condition
at mixing zone walls is studied numerically to investigate the effect of Reynolds number
(10 to 50), power-law index (0.6161 to 1), Nusselt number (104 to 106) for external air
flows and dimensionless ambient temperature ( 2.7 to 1.3). The temperature is a passive
tracer that quantifies the degree of mixing in this study. Detailed kinematics shows the formation
of recirculation zones at the mixing channel walls. Length required to achieve the
well mixed condition (i.e., a flat temperature profile across the channel height) is shorter at
low Reynolds number, convective heat transfer coefficient and ambient temperature, and
high power-law index values. In the impingement zone, a faster reduction in mixing index
has been observed with respect to mixing length at high power-law index and low
Reynolds numbers, while Nusselt number and ambient temperature exert only a weak influence.
Under appropriate conditions, significant energy exchange between the system and
surroundings can occur and has been analyzed in detail in this work. This work finds its
applications in the improved mixing as practiced in the processing and production of foodstuffs,
fine chemicals, personal care products, etc.
