Barbosa, Tiago M.Ramos, Rui J.Silva, A.J.Marinho, D.A.2017-12-152017-12-152018Barbosa, Tiago M.; Ramos, Rui; Silva, A.J.; Marinho, D.A. (2018). Assessment of passive drag in swimming by numerical simulation and analytical procedure. Journal of Sports Sciences. ISSN 0264-0414. 36:5, p. 492-4980264-0414http://hdl.handle.net/10198/14735The aim was to compare the passive drag-gliding underwater by a numerical simulation and an analytical procedure. An Olympic swimmer was scanned by computer tomography and modelled gliding at a 0.75-m depth in the streamlined position. Steady-state computer fluid dynamics (CFD) analyses were performed on Fluent. A set of analytical procedures was selected concurrently. Friction drag (Df), pressure drag (Dpr), total passive drag force (Df +pr) and drag coefficient (CD) were computed between 1.3 and 2.5 m · s−1 by both techniques. Df +pr ranged from 45.44 to 144.06 N with CFD, from 46.03 to 167.06 N with the analytical procedure (differences: from 1.28% to 13.77%). CD ranged between 0.698 and 0.622 by CFD, 0.657 and 0.644 by analytical procedures (differences: 0.40–6.30%). Linear regression models showed a very high association for Df +pr plotted in absolute values (R2 = 0.98) and after log–log transformation (R2 = 0.99). The CD also obtained a very high adjustment for both absolute (R2 = 0.97) and log–log plots (R2 = 0.97). The bias for the Df +pr was 8.37 N and 0.076 N after logarithmic transformation. Df represented between 15.97% and 18.82% of the Df +pr by the CFD, 14.66% and 16.21% by the analytical procedures. Therefore, despite the bias, analytical procedures offer a feasible way of gathering insight on one’s hydrodynamics characteristicengDrag coefficientFriction dragGliding pressureDrag swimmingjournal article10.1080/02640414.2017.1321774