Cj. Bolinder et B. Sunden, NUMERICAL PREDICTION OF LAMINAR-FLOW AND FORCED CONVECTIVE HEAT-TRANSFER IN A HELICAL SQUARE DUCT WITH A FINITE PITCH, International journal of heat and mass transfer, 39(15), 1996, pp. 3101-3115
Fully developed laminar forced convective heat transfer in helical squ
are duels is studied numerically using a finite-volume method. The H1
thermal boundary condition is applied. Dean numbers up to 510 and Pran
dtl numbers between 0.005 and 500 are considered. Correlations for the
mean Nusselt number are proposed. For a toroidally curved duel, two s
olution branches with a two-vortex secondary flow and one branch with
a four-vortex flow are detected. The four-vortex solutions give, for h
igh Pr, mean Nusselt numbers up to twice those of the two-vortex solut
ions. For ducts of small pitcher torsion, the flow and heat transfer c
haracteristics are similar to those of a toroidally curved duct with t
he same dimensionless curvature epsilon. Copyright (C) 1996 Elsevier S
cience Ltd.