Laminar Flow and Heat Transfer to a Non-Newtonian Fluid in an Entrance Region of a Square Duct with Prescribed Constant Axial Wall Heat Flux

Abstract

Forced-convection heat transfer information asa function of the pertinent nondimemional numbers is obtained numerically for laminar incompressible non-Newtonian fluid flow in the entrance region of a square duct with simultaneously developing temperature and velocity profiles for constant axial wall heat flux with uniform peripheral wall temperature. The power-law model chomcterizes the non-Newtonion behavior. Finite-difference representotions are developed for the equations of fhe mothematical model, and numerical solutions are obtoined assuming uniform inlet velocity and tempemture distributions. Results are presented for local and mean Nusselt numbers 0s functions of the Groetz number and the Pmndtl number in the entrance region Comparisons are made with previous atwlytical work for Newtonian fluiak The results show a strong effect of the Prondtl number on the Nusselt numbers with fully developed and uniform velocity prcfZes representing the lower and upper limits, respectively. The results provide a new insight into the m e three-dimemional character of the pseudoplastic fluid flow in the entrance region of a square duct and are occwate.

Analysis of Multilayer Mini- and Microchannel Heat Sinks in Single-Phase Flow Using One- and Two-Equation Porous Media Models

“…where the value of Nu as a function of the thermal entry length has been given by Chandrupatla and Sastri [14].…”

Experimental Study of Heat Transfer to Pseudoplastic Fluids in Square and Circular Pipes

“…Entrance region effects in circular pipes have been analytically studied by McKillop (1964) while Chandrupatla and Sastri's (1978a) work was concerned with square ducts. Mizushina et al (1967) conducted an experimental study of heat transfer to methocel solutions flowing in a circular pipe whose walls were subjected to uniform heat flux.…”