ISSN Online: 2377-424X
ISBN Print: 0-89116-299-2
International Heat Transfer Conference 7
EFFECT OF WEISSENBERG NUMBER ON TURBULENT HEAT TRANSFER OF AQUEOUS POLYACRYLAMIDE SOLUTIONS
Resumo
Simultaneous measurements of friction and heat transfer coefficients for drag-reducing polyacrylamide solutions flowing turbulently in circular pipes were conducted in two different modes: 1) a once-through system in which fluid degradaion was kept to a minimum and 2) a recirculating flow system in which the fluid was allowed to deqrade. In the analysis of the resulting friction
and heat transfer data, the characteristic time of
each test solution was calculated using the Powell-Eyring
model so that both friction and heat transfer
results could be expressed as functions of the
Reynolds and Weissenberg numbers.
The critical Weissenberg number for heat transfer for aqueous polyacrylamide solutions is found to be of the order of 200-250, above which the turbulent heat transfer lies on the minimum heat transfer asymptotic line. For these same solutions, the critical Weissenberg number for friction is of the order of 5-10, above which the turbulent friction lies on the minimum friction asymptotic line.
The critical Weissenberg number for heat transfer for aqueous polyacrylamide solutions is found to be of the order of 200-250, above which the turbulent heat transfer lies on the minimum heat transfer asymptotic line. For these same solutions, the critical Weissenberg number for friction is of the order of 5-10, above which the turbulent friction lies on the minimum friction asymptotic line.