Heat Transfer and Pressure Drop Measurements of Rotating Rib-Roughened Parallelogram Channel

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 ReynoldsRe, rotationRo, 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 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 factors are in the range of 0.979–1.575 for the present test conditions.