Flow over a cylinder subjected to combined translational and rotational oscillations

Nazarinia, Mehdi; Jacono, David Lo; Thompson, Mark C.; Sheridan, John

doi:10.1016/j.jfluidstructs.2011.05.005

Cited by 18 publications

(4 citation statements)

References 33 publications

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“…The majority of the aforementioned research focused on synchronisations with N = 1 for a transversely oscillatory cylinder and N = 2 for an in-line oscillatory cylinder, which is normally referred to as the primary synchronisation or 'lockon'. Although this synchronisation phenomenon is best known for the translational oscillation, similar wake synchronisation has also been observed for rotatory oscillation circular cylinders (Baek & Sung 2000;D'Adamo, Godoy-Diana & Wesfreid 2011) or the combined movements (Nazarinia et al 2012).…”

Section: Introductionsupporting

confidence: 57%

Modes of synchronisation in the wake of a streamwise oscillatory cylinder

et al. 2017

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A numerical analysis of flow around a circular cylinder oscillating in-line with a steady flow is carried out over a range of driving frequencies $(f_{d})$ at relatively low amplitudes $(A)$ and a constant Reynolds number of 175 (based on the free-stream velocity). The vortex shedding is investigated, especially when the shedding frequency $(f_{s})$ synchronises with the driving frequency. A series of modes of synchronisation are presented, which are referred to as the $p/q$ modes, where $p$ and $q$ are natural numbers. When a $p/q$ mode occurs, $f_{s}$ is detuned to $(p/q)f_{d}$, representing the shedding of $p$ pairs of vortices over $q$ cycles of cylinder oscillation. The $p/q$ modes are further characterised by the periodicity of the transverse force over every $q$ cycles of oscillation and a spatial–temporal symmetry possessed by the global wake. The synchronisation modes $(p/q)$ with relatively small natural numbers are less sensitive to the change of external control parameters than those with large natural numbers, while the latter is featured with a narrow space of occurrence. Although the mode of synchronisation can be almost any rational ratio (as shown for $p$ and $q$ smaller than 10), the probability of occurrence of synchronisation modes with $q$ being an even number is much higher than $q$ being an odd number, which is believed to be influenced by the natural even distribution of vortices in the wake of a stationary cylinder.

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Section: Introductionsupporting

confidence: 57%

Modes of synchronisation in the wake of a streamwise oscillatory cylinder

et al. 2017

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“…Experimental studies have been performed by Tokumaru & Dimotakis (1991), Fujisawa, Kawaji & Ikemoto (2001), Fujisawa, Tanahashi & Srinivas (2005), Lee & Lee (2006), Saad, Lee & Lee (2007), Lee & Lee (2008), Nazarinia et al (2012) and, most recently, Kumar et al (2013) 552 P. Sellappan and T. Pottebaum and Sellappan & Pottebaum (2014). Tokumaru & Dimotakis (1991) conducted an experimental study at Re = 15 000, performing flow visualization and wake profile measurements on circular cylinders undergoing forced rotary oscillations in a steady uniform flow and found that the drag forces on the cylinder were reduced at high oscillation frequencies while undergoing rotary forcing.…”

Section: Vortex Shedding From Cylindersmentioning

confidence: 99%

“…They also studied the possibility of forcing the wake to become two-dimensional through rotary forcing at Re = 185 and Re = 400 and identified forcing conditions under which it is possible to do so. One experimental study that looked at a slightly different forcing configuration was by Nazarinia et al (2012). They studied cylinders in a uniform flow at Re = 1322 undergoing combined rotary and translational forcing and found wake modes similar to those observed for cylinders undergoing rotary forcing only.…”

Section: Vortex Shedding From Cylindersmentioning

confidence: 99%

Vortex shedding and heat transfer in rotationally oscillating cylinders

Sellappan

Pottebaum

2014

J. Fluid Mech.

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Wake formation and heat transfer from a rotationally oscillating circular cylinder in cross-flow at Re = 750 are studied. Two aspects, the effect of cylinder forcing on vortex shedding and the effect of the wake structures on convective heat transfer, are studied. Cylinder forcing conditions range between 0.09 θ PP 2.09, where θ PP is the peak-to-peak oscillation amplitude in radians and 0.70 F R 3.16, where F R is the ratio of forcing frequency to natural shedding frequency. Digital particle image velocimetry (DPIV) is used to obtain quantitative wake structure information. Wake modes, and regions of the parameter space in which they occur, are identified for both heated and unheated cylinders. For the heated cylinder, cylinder forcing is found to affect the convective heat-transfer rate. Certain wake modes, including newly discovered wake modes synchronized over multiple oscillation cycles, are found to correlate with significant heat-transfer enhancement. Cylinder tangential velocity is also found to affect the heat-transfer rate in certain regions of the parameter space.

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“…They noted the potential for symmetry-breaking cases, which occur as the phase shift between rotary and translational oscillation is varied, but only observed a jet flow in the in-phase and opposing-phase cases. In two related studies, Nazarinia et al (2009aNazarinia et al ( , 2012 looked at the effects of phase shift, velocity ratios and motion frequency for a cylinder undergoing combined rotary and translational oscillation in a cross-flow. The free-stream velocity in both of these studies was more than 100 % of the maximum prescribed translational velocity.…”

Section: Introduction and Related Workmentioning

confidence: 99%

Flows produced by the combined oscillatory rotation and translation of a circular cylinder in a quiescent fluid

et al. 2014

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Flows produced by a circular cylinder undergoing oscillatory rotation and translation in a quiescent fluid have been studied via direct numerical simulations. The incompressible Navier-Stokes equations were solved for large dimensionless time windows using an immersed boundary method with adaptive Cartesian grid refinement. Parametric studies were conducted in two dimensions on the Reynolds number, Keulegan-Carpenter number and phase shift. In addition to the previously reported net thrust case (Blackburn et al., Phys. Fluids, vol. 11, 1999, pp. 4-6), the study catalogued the appearance of several streaming jet regimes with varying deflection angles, deflected and horizontal vortex shedding regimes, and a double mirrored jet regime with varying inter-jet angles, as well as several chaotic cases. Visualizations are presented to clarify each observed flow regime and to illustrate the parameter space. Connections are drawn between these canonical bluff-body deflected wakes and a similar phenomenon observed in aerofoils oscillating at high reduced frequencies in a cross-flow. Also, the discovery of the streaming jet regimes with varying deflection angles opens the door for using these flows as a low-Reynolds-number propulsive mechanism requiring only a two-degree-of-freedom actuator. Simulation results suggest that the flow phenomena observed in two dimensions persist in three dimensions, despite spanwise fluctuations.

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Flow over a cylinder subjected to combined translational and rotational oscillations

Cited by 18 publications

References 33 publications

Modes of synchronisation in the wake of a streamwise oscillatory cylinder

Modes of synchronisation in the wake of a streamwise oscillatory cylinder

Vortex shedding and heat transfer in rotationally oscillating cylinders

Flows produced by the combined oscillatory rotation and translation of a circular cylinder in a quiescent fluid

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