A numerical investigation of the near-wake structure in the variable frequency forced oscillation of a circular cylinder

Atluri, Sampath; Rao, V.V. Bapeswara; Dalton, Charles

doi:10.1016/j.jfluidstructs.2008.06.012

Cited by 24 publications

(14 citation statements)

References 25 publications

(27 reference statements)

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“…They suggested that πD as the minimum spanwise length is enough to capture the main wake parameters at high Reynolds number. [13] performed extensive 2-D LES of forced oscillating cylinder with a range of modulated excitation frequencies from Re=500 to 6000 and found good agreements with experimental results of wake modes. Recently,…”

Section: Introductionsupporting

confidence: 52%

Large Eddy Simulation of Flow Past a Stationary and Controlled Oscillating Circular Cylinder at Re=5500

Kim

Wilson

Chen

2013

Volume 7: CFD and VIV

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Vortex shedding from a stationary cylinder and transversely oscillating circular cylinder in a uniform flow at a Reynolds number of 5500 is numerically studied by three-dimensional Large Eddy Simulation (LES). The filtered equations are discretised using the finite volume method with an O-type structured grid and a second-order accurate method in both time and space. Firstly, the main wake parameters of a stationary cylinder are examined and compared for different grid resolutions. Secondly, a transversely oscillating cylinder with a constant amplitude in a uniform flow is investigated. The cylinder oscillation frequency ranges between 0.75 and 0.95 of the natural Kármán frequency, and the excitation amplitude is 50% of the cylinder diameter. Comparisons with the available experimental data indicate that the present study has properly predicted the flow statistics of the cylinder wake for both the fixed and oscillating cylinder case, and numerically captured the vortex switching phenomenon, which is characterized by changes in forces and wake mode of shedding observed in the previous experiments at high values of Reynolds number.

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Section: Introductionsupporting

confidence: 52%

Large Eddy Simulation of Flow Past a Stationary and Controlled Oscillating Circular Cylinder at Re=5500

Kim

Wilson

Chen

2013

Volume 7: CFD and VIV

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“…The input variable is the lift coefficient C L because this is the only term on Equation (24) that changes with the time. The lift coefficient has a sinusoidal time waveform as it is shown in Atluri et al [50].…”

Section: Piezoelectric Power Controlmentioning

confidence: 98%

Power Control Optimization of an Underwater Piezoelectric Energy Harvester

et al. 2018

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Abstract:Over the past few years, it has been established that vibration energy harvesters with intentionally designed components can be used for frequency bandwidth enhancement under excitation for sufficiently high vibration amplitudes. Pipelines are often necessary means of transporting important resources such as water, gas, and oil. A self-powered wireless sensor network could be a sustainable alternative for in-pipe monitoring applications. A new control algorithm has been developed and implemented into an underwater energy harvester. Firstly, a computational study of a piezoelectric energy harvester for underwater applications has been studied for using the kinetic energy of water flow at four different Reynolds numbers Re = 3000, 6000, 9000, and 12,000. The device consists of a piezoelectric beam assembled to an oscillating cylinder inside the water of pipes from 2 to 5 inches in diameter. Therefore, unsteady simulations have been performed to study the dynamic forces under different water speeds. Secondly, a new control law strategy based on the computational results has been developed to extract as much energy as possible from the energy harvester. The results show that the harvester can efficiently extract the power from the kinetic energy of the fluid. The maximum power output is 996.25 µW and corresponds to the case with Re = 12,000.

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“…A method for controlling vortex shedding is to attach a plate at the back of a circular cylinder or to control wakes by using another cylinder, to disturb the inflow or absorb and spout fluid on the cylinder surface, to periodically oscillate the cylinder, etc. Accordingly, flow around an oscillating circular cylinder has been studied and it is yet an object of important numerical computation [1,2,3].…”

Section: Introductionmentioning

confidence: 99%

“…The circular cylinder has its characteristic Karman vortex shedding frequency which is dependent on the Reynold's number. The lock-on happens when the oscillation frequency of the cylinder is approximately same or similar to the Karman vortex shedding frequency [1,2,3].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Analysis of Unsteady Flow around a Transversely Oscillating Circular Cylinder

Moon¹,

Kim²

2012

International Journal of Aeronautical and Space Sciences

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The relationship between the excitation frequency and the vortex shedding frequency is analyzed during the oscillation of the circular cylinder. Two-dimension unsteady Navier-Stoke's equation is calculated by using the Optimized High Order Compact (OHOC) scheme. The flow condition is Mach number 0.3 and Reynold's number 1000. From the results acquired by calculation, it can be inferred that, when the excitation frequency is near the vortex shedding frequency at the fixed cylinder wake, the oscillation frequency of lift and drag coefficients appears to lock-on. The lock-on refers to a phenomenon in which the aerodynamic coefficient appears as one primary oscillation frequency through excitation and its amplitude is amplified. In the non-lock-on zone, the excitation frequency is not in the lock-on mode anymore and beat is formed in which two or more primary oscillation frequencies of the aerodynamic coefficient are mixed together.

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A numerical investigation of the near-wake structure in the variable frequency forced oscillation of a circular cylinder

Cited by 24 publications

References 25 publications

Large Eddy Simulation of Flow Past a Stationary and Controlled Oscillating Circular Cylinder at Re=5500

Large Eddy Simulation of Flow Past a Stationary and Controlled Oscillating Circular Cylinder at Re=5500

Power Control Optimization of an Underwater Piezoelectric Energy Harvester

Numerical Analysis of Unsteady Flow around a Transversely Oscillating Circular Cylinder

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