Buoyant high-pressure transcritical fluid duct flows

Abstract

In this work, direct numerical simulations of a high-pressure transcritical square duct flow with distinct gravity directions in the cross-stream plane are performed. The buoyancy effects on the instantaneous and mean fields are analyzed. Significant differences are highlighted in the distributions of Prandtl’s second-kind motions due to a strong coupling effect between the high-pressure transcritical phenomena and the buoyancy effects. The observed phenomena indicate that prior characterizations of secondary flows and their contribution to heat and mass transfer (commonly considered as independent from the Reynolds number) do not apply in cases above the critical regime where strong variations in thermophysical properties are found. Furthermore, the number and dynamics of these secondary flows are significantly affected by the gravity direction.

Peer Reviewed

Postprint (published version)