MASS-TRANSFER ENTRANCE LENGTHS IN DILUTE POLYMER-SOLUTIONS

The aim of this study is to investigate the effect of dilute polymer solutions, frequently used as drag-reducing agents, on mass transfer entrance lengths. transfer This work presents firsthand experimental evidence on the variation of local mass transfer coefficients which clearly indicates that in fully developed flows at high Schmidt numbers the mass transfer entrance lengths are only of the order of one to two tube diameters for both Newtonian fluids, with or without drag-reducing agents. We cannot conclusively comment on the apparent difference between heat and mass transfer entry lengths.