Journal ArticleDOI
Effects of shear intensity and aspect ratio on three-dimensional wake characteristics of flow past surface mounted circular cylinder
TLDR
In this article, three-dimensional numerical computations have been carried out for flow past a surface mounted finite height circular cylinder using Open Source Field Operation and Manipulation (OFOM).Abstract:
Three-dimensional numerical computations have been carried out for flow past a surface mounted finite height circular cylinder using Open Source Field Operation and Manipulation. Flow field characteristics have been investigated for fixed Reynolds number equal to 300 and varying aspect ratios (AR being the ratio of height to diameter of the cylinder) from 1 to 5. The effect of nonuniform flow (linear shear) with shear intensity (K) ranging from 0 to 0.3 on flow field characteristics has been examined using iso-Q surfaces and streamline plots. Three different flow regimes are reported based on the values of AR and K: steady flow, symmetric mode, and antisymmetric mode of vortex shedding. The formation of critical points (impingement point, source, and spiral node) has been explained using the time-averaged flow field in the longitudinal plane of symmetry. Surface flow topology has been presented with the help of limiting streamlines on the surface of the cylinder. Variation in mean drag coefficient with a change in K has also been reported. Unsteady periodic and aperiodic wake flows have been characterized using the Hilbert spectra of the transverse velocity signal at a point in the wake. The extent of nonlinear interaction in the wake and its influence on frequency distribution have been analyzed using marginal spectra and quantified in terms of degree of stationarity.read more
Citations
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Journal Article
Large Eddy Simulation of Turbulent Flow for Wall Mounted Cantilever Cylinders of Aspect Ratio 6 and 10
TL;DR: The flow structure around wall mounted circular cylinders of finite heights is numerically investigated via large eddy simulation (LES) and regular vortex shedding is found in the wake of the higher aspect ratio case as was anticipated, along with a strong downwash originating from the flow over the free end of the cylinder.
Journal ArticleDOI
Three-dimensional spectral proper orthogonal decomposition analyses of the turbulent flow around a seal-vibrissa-shaped cylinder
Journal ArticleDOI
Turbulent boundary layer perturbation by two wall-mounted cylindrical roughness elements arranged in tandem: Effects of spacing and height ratio
TL;DR: In this paper, the effects of roughness elements in close proximity on the wake of a turbulent boundary layer were investigated in a water channel using planar particle image velocimetry.
Journal ArticleDOI
Effect of incoming shear on unsteady wake in flow past surface mounted polygonal prism
Prashant Kumar,Shaligram Tiwari +1 more
TL;DR: In this paper, the effect of impinging shear at the inlet (shear intensity, K) on three-dimensional vortex structures has been explored using iso-Q surfaces for the varying Reynolds number (Re) ranging from 60 to 200 and fixed aspect ratio equal to 5.
Journal ArticleDOI
Turbulent structures and characteristics of flows past a vertical surface-piercing finite circular cylinder
TL;DR: In this article , the velocity profile, separation angle, vorticity, and turbulent kinematic energy at different spanwise positions exhibit strong three-dimensionalality, including the outward-spreading trend at the interface and the fluctuation induced by the upwash flow near the free end.
References
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On Dynamic Mode Decomposition: Theory and Applications
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