TY - GEN
T1 - Laminar forced convection in axisymmetric ducts with streamwise variation in radius for materials processing applications
AU - Lee, S. H.K.
AU - Jaluria, Y.
PY - 1992
Y1 - 1992
N2 - A numerical study of laminar forced convection in an axisymmetric duct with streamwise variation in radius has been carried out. Such transport circumstances are of interest in many practical processes such as injection molding, glass molding, fiber drawing and extrusion, where the flow rates are generally small enough to give rise to a laminar flow. Developing flow and thermal fields in straight ducts and converging ducts with wall conditions of constant temperature and constant external heat transfer coefficient were investigated as well as flow in a sinusoidally converging-diverging duct with constant wall temperature. The time-dependent conservation equations for streamfunction, vorticity and energy were transformed and solved on a non-uniform mesh using a pseudo-transient numerical scheme. For both the straight and converging-diverging ducts, the results were in good agreement with those in the literature. For the converging duct subjected to an external heat transfer with constant heat transfer coefficient, a local increase in Nusselt number is achieved along with a sharp rise in the wall temperature. This increase in Nusselt number is not significantly affected by changes in the Reynolds number and differences in diameters, but is largely due to the actual converging process. For the converging duct with a constant wall temperature, the mechanism of increasing the Nusselt number is different from the constant heat transfer coefficient case, in that it is due to the narrowing of the thermal region. The results obtained indicate the relevant variations of the flow and thermal fields in the ducts as well as the heat transfer rates.
AB - A numerical study of laminar forced convection in an axisymmetric duct with streamwise variation in radius has been carried out. Such transport circumstances are of interest in many practical processes such as injection molding, glass molding, fiber drawing and extrusion, where the flow rates are generally small enough to give rise to a laminar flow. Developing flow and thermal fields in straight ducts and converging ducts with wall conditions of constant temperature and constant external heat transfer coefficient were investigated as well as flow in a sinusoidally converging-diverging duct with constant wall temperature. The time-dependent conservation equations for streamfunction, vorticity and energy were transformed and solved on a non-uniform mesh using a pseudo-transient numerical scheme. For both the straight and converging-diverging ducts, the results were in good agreement with those in the literature. For the converging duct subjected to an external heat transfer with constant heat transfer coefficient, a local increase in Nusselt number is achieved along with a sharp rise in the wall temperature. This increase in Nusselt number is not significantly affected by changes in the Reynolds number and differences in diameters, but is largely due to the actual converging process. For the converging duct with a constant wall temperature, the mechanism of increasing the Nusselt number is different from the constant heat transfer coefficient case, in that it is due to the narrowing of the thermal region. The results obtained indicate the relevant variations of the flow and thermal fields in the ducts as well as the heat transfer rates.
UR - http://www.scopus.com/inward/record.url?scp=0026999358&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026999358&partnerID=8YFLogxK
M3 - Conference contribution
SN - 079181050X
T3 - American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD
SP - 27
EP - 34
BT - Fundamentals of Forced Convection Heat Transfer
PB - Publ by ASME
T2 - Winter Annual Meeting of the American Society of Mechanical Engineers
Y2 - 8 November 1992 through 13 November 1992
ER -