LAMINAR-FLOW HEAT-TRANSFER TO VISCOUS POWER-LAW FLUIDS IN DOUBLE-SINEDUCTS

Fully developed, constant properly, laminar flows of viscous power-law fluids in double-sine shaped ducts are considered. The double-sine cr oss section represents a limiting inter-plate channel geometry in plat e heat exchangers with sinusoidally corrugated plates. The non-Newtoni an fluid rheology is described by the power-law or Ostwald-de Waele mo del, and shear thinning (n < I) as well as shear thickening (n > I) fl ows are considered. Both fluid flow and convective heat transfer probl ems under (T) and (HI) thermal boundary conditions are analyzed. Analy tical solutions based on the Galerkin integral method are presented fo r a; wide range of flow behavior index (0.15 less than or equal to n l ess than or equal to 2.5) and duct aspect ratio (0.25 less than or equ al to gamma less than or equal to 4.0). The effects of fluid rheology (pseudoplasticity or dilatancy), duct geometry, and thermal boundary c onditions on the velocity and temperature field, are delineated. Also, isothermal friction factor and Nusselt number results for various con ditions are presented, and strategies for predicting fRe and Nu are ev aluated. Copyright (C) 1996 Elsevier Science Ltd.