Two-dimensional space-time finite-element simulations are carried out to study the free vibrations of a rigid elliptic cylinder of aspect ratio 1.11 and low non-dimensional mass of unity. Undamped transverse-only as well as two-degrees-of-freedom oscillations are considered. The effect of damping is investigated on transverse-only motion. For all three cases, results for cylinder response are presented for 50≤Re≤180. In the absence of damping, transverse oscillations are mostly periodic except for a very narrow region near the end of lock-in. In contrast, a damping of 0.044 removes quasi-periodicity as well as secondary hysteresis from flow and body motion. For undamped motion, inclusion of in-line oscillations excites high amplitude oscillations, widens the range of synchronization and delays phase shift between lift and cross-stream response. In each case, synchronization between cylinder oscillations and vortex-shedding is 1:1. In addition, drag-lift phase plots are symmetric about mean lift (= 0) line. Thus, symmetrical shedding of two equally strong alternate vortices per oscillation cycle forms 2S, CNW(2S) or C(2S) modes. For each case, the lower branch initiates at Re = 65 where the oscillation or shedding frequency is found to be locally maximum.
Sourav, K., & Sen, S. (2017). On the Response of a Freely Vibrating Thick Elliptic Cylinder of Low Mass Ratio. Journal of Applied Fluid Mechanics, 10(3), 899-913. doi: 10.18869/acadpub.jafm.73.240.26946
MLA
K. Sourav; S. Sen. "On the Response of a Freely Vibrating Thick Elliptic Cylinder of Low Mass Ratio", Journal of Applied Fluid Mechanics, 10, 3, 2017, 899-913. doi: 10.18869/acadpub.jafm.73.240.26946
HARVARD
Sourav, K., Sen, S. (2017). 'On the Response of a Freely Vibrating Thick Elliptic Cylinder of Low Mass Ratio', Journal of Applied Fluid Mechanics, 10(3), pp. 899-913. doi: 10.18869/acadpub.jafm.73.240.26946
VANCOUVER
Sourav, K., Sen, S. On the Response of a Freely Vibrating Thick Elliptic Cylinder of Low Mass Ratio. Journal of Applied Fluid Mechanics, 2017; 10(3): 899-913. doi: 10.18869/acadpub.jafm.73.240.26946