A Numerical Study of Flow and Heat Transfer in a Smooth and Ribbed U-Duct With and Without Rotation

摘要

Computations were performed to study the three-dimensional flow and heat transfer in a U-shaped duct of square cross section under rotating and non-rotating conditions. The Parameters investigated were two rotation numbers (0,0.24) and smooth versus ribbed Wall at a Reynolds number of 25,000, a density ratio of 0.13, and an inlet Mach number Of 0.05. results are presented for streamlines, velocity vector fields, and contours of Mach number, pressure, temperature, and Nusselt numbers. These results show how fluid flow in A U-duct evolves form a unidirectional one to one with convoluted secondary flows be- Cause of Coriolis force, centrifugal buoyancy, staggered inclined ribs, and a 180 deg Bend.