Chi-Tzung WangCHIN-CHOU CHUCHIEN-CHENG CHANG2023-01-312023-01-311994-01-01https://scholars.lib.ntu.edu.tw/handle/123456789/627483The behaviour of a viscous vortex ring is examined by a matched asymptotic analysis up to three orders. This study aims at investigating how much the location of maximum vorticity deviates from the centroid of the vortex ring, defined by P.G. Saffman (1970). All the results are presented in dimensionless form. Only in the limit of Re right arrow infinity , the values of H"SUB m" and H"SUB c" are found to coincide with each other, while the deviation of H"SUB m" from the constant H"SUB c" is getting significant with decreasing the Reynolds number. Also of interest is that the radial motion is shown to exist for the trajectory of maximum vorticity at finite Reynolds numbers. The present analysis clarifies the earlier discrepancy between Saffman's result and that obtained by C. Tung and L. Ting (1967). (from Authors)journal article2-s2.0-0028083912https://api.elsevier.com/content/abstract/scopus_id/0028083912