Detailed Heat Transfer Distributions and Pressure Drop Measurements for a Rotating Parallelogram Channel With Radially Outward Flow

This experimental study examines the pressure drop coefficients (f) and the detailed Nusselt numbers (Nu) distributions over two opposite leading and trailing walls roughened by 45° 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≤15000, 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 Nu 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 of the stationary levels; while the η factors are in the range of 0.979–1.575 for the present test conditions.