2010 年 38 巻 1 号 p. 9-16
In order to investigate the secondary flow patterns of viscoelastic swirling flows in a cylindrical casing with a partially rotating disc, the numerical simulation of the confined swirling flow was performed at low Reynolds numbers, in which the Giesekus model was used as a constitutive equation. The Giesekus model parameters were obtained for polyacrylamide solutions whose concentrations were from 0.025 wt% to 0.2 wt%. The aspect ratio of the distance H between the casing end wall and the rotating disk to the container radius Rc was fixed to H/Rc = 2.0. The ratio of rotating disc radius Rd to Rc, s = Rd /Rc, was 0.4, 0.6 and 1.0. Five kinds of secondary flow patterns, which were classified using the Reynolds and elastic numbers, were observed, which was almost independent of the s.