Abstract
This experimental study examines the pressure-drop coefficients f and the detailed Nusselt number Nu distributions over two opposite leading and trailing walls roughened by 45 deg ribs for a rotating parallelogram channel with radially outward flow. For the first time, the isolated effects of Reynolds Re, rotation Ro, and buoyancy Bu numbers on local and area-averaged Nusselt numbers Nu and Nu measured from the infrared thermography method were successfully examined at the parametric conditions of 5000 ≤ Re ≤ 15; 000, 0 ≤ Ro ≤0:3, and 0:001 ≤ Bu ≤ 0:23 for the single-pass parallelogram channel. A set of selected heat transfer data illustrates the Coriolis and rotating-buoyancy effects on the detailed Nusselt number distributions and the area-averaged heat transfer performances of the rotating parallelogram channel. With the consideration of the f data generated at the isothermal conditions, the thermal performance factors η for this radially rotating channel were evaluated. The Nusselt numbers obtained from the leading and trailing walls of the rotating test channel fall in the respective ranges of 0.78-1.34 and 1.09-1.38 times the stationary levels, whereas the η factors are in the range of 0.979-1.575 for the present test conditions. Copyright © 2011 by the American Institute of Aeronautics and Astronautics, Inc.