Wall heating effect on local heat transfer in a rotating two-pass square channel with 90° rib turbulators

• Published in: International journal of heat and mass transfer Vol. 37; no. 9; pp. 1411 - 1420
• Main Authors: Parsons, James A., Je-Chin, Han, Yuming, Zhang
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1994; Elsevier
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Cooling by air; Turbulence generator; Nusselt number; Cooling system; Turbine blade; Gas turbine; Experimental study; Heat transfer
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/0017-9310(94)90187-2

The influence of wall heating condition on the local heat transfer coefficient in a rotating, two-pass, square channel with 90° transverse ribs on the leading and trailing walls was investigated for Reynolds numbers from 2500 to 25000 and rotation numbers from 0 to 0.352. Three thermal boundary condition cases were studied: (A) all four walls at the same temperature, (B) all four walls at the same heat flux, and (C) trailing wall hotter than leading with side walls unheated and insulated. The results for case A show that the ribbed wall heat transfer coefficients with rotation increase by a factor of two to three over the smooth wall data with rotation. As rotation number (or buoyancy parameter) increases, the heat transfer coefficients on the first pass (outflow) trailing wall increase and on the first pass leading wall decrease. The reverse is true for the second pass (inflow). The heat transfer coefficients on the first pass leading and second pass trailing walls for cases B and C are 50% higher than those for case A.