Experimental investigation on flow-induced vibration of the flexible cylinder with attached flexible splitter plate

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(1)

Published: Jan. 1, 2025

This experimental study investigates a flexible circular cylinder's flow-induced vibrations (FIV) with an attached splitter plate. The system's dynamic response was analyzed for three plate widths: 1D, 2D, and 3D, where D is the diameter, compared to bare cylinder. At low reduced velocities, cylinder exhibited oscillations in its first two bending modes, presence of resulted up 70% reduction oscillation amplitudes. higher amplitude 1D remained below that In contrast, amplitudes increased monotonically 2D 3D plates, reaching four times cylinder, respectively. Multi-frequency were observed wider plates. Flow field analysis, incorporating both quantitative qualitative methods, along proper orthogonal decomposition flow field, identified distinct FIV types: experienced galloping type widths vortex-induced vibration

Language: Английский

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Energy evolution in the Kármán vortex street of compressible flow around a circular cylinder

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(2)

Published: Feb. 1, 2025

In this study, compressible flow around a circular cylinder is investigated at Reynolds number (Re = 50, 100, 150, 200) and Mach (Ma 0.1, 0.3, 0.5, 0.6) using direct numerical simulation. The energy evolution vortex dynamics within the Kármán street are discussed, with case of Re 150 Ma 0.5 serving as representative example. kinetic involves three key regions: region E supplies to vortices, I causes vortices deflection expansion, S promotes separation, transport dominating variation in energy. Through time-averaged statistical results, we divide near wake into several zones, each revealing impact non-uniformity, unsteady effects, viscous forces on redistribution. Unsteady effects predominant main passage, while non-uniformity prevails areas swept by head tail. Furthermore, numbers further explored. results reveal that increases, strength vortex-shedding frequency enlarged, leading an enhanced However, variations have minimal these processes. At higher Re, become more pronounced, low-energy regions shift closer cylinder.

Language: Английский

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Near-wall effect on vortex dynamics in the flow around a rectangular cylinder

Journal of Fluid Mechanics, Journal Year: 2025, Volume and Issue: 1011

Published: May 13, 2025

This study presents a novel investigation into the vortex dynamics of flow around near-wall rectangular cylinder based on direct numerical simulation at $Re=1000$ , marking first in-depth exploration these phenomena. By varying aspect ratios ( $L/D = 5$ $10$ $15$ ) and gap $G/D 0.1$ $0.3$ $0.9$ ), reveals influenced by effect, considering incoming laminar boundary layer flow. Both $L/D$ $G/D$ significantly influence dynamics, leading to behaviours not observed in previous bluff body flows. As increases, streamwise scale upper edge (ULE) recirculation grows, delaying reattachment. At smaller lower (LLE) is suppressed, with Kelvin–Helmholtz vortices merging form ULE vortex, followed instability, differing from conventional dynamics. Larger promotes formation an LLE shear layer. An intriguing finding backward fluid downstream region side cylinder. 0.3$ double-trailing-edge emerge for larger two distinct associated interactions between wall recirculation. These lead different multiple separations. For 0.9$ secondary (SV) plate induces tertiary Double-SVs are . Frequency locking most cases, but suppressed 10$ where competing shedding modes evolutions SV.

Language: Английский

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Experimental and numerical study on smoke bifurcation in L-shaped passage fire under stack effect

International Communications in Heat and Mass Transfer, Journal Year: 2025, Volume and Issue: 165, P. 109075 - 109075

Published: May 14, 2025

Language: Английский

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Vortex dynamics induced by a finite wall-mounted cylinder with various corner shapes

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(7)

Published: July 1, 2024

The flow around a finite wall-mounted cylinder with four different corner shapes (R/D=0,1/6,1/3,1/2) is numerically investigated at Reynolds number of 1000 and height-to-diameter ratio 4. For the vortex dynamics, structures in wake undergo series complex evolution processes, namely, shear layer separation, C vortex, Reverse hairpin breakdown. influence R/D on characteristics has been studied. results indicate that mean hydrodynamic coefficients (C¯d C¯l) reattachment distance (LP/D) decrease increasing R/D. Moreover, separation for R/D=1/2 delayed by 0.49D compared to R/D=0. probability density function reverse-flow area exhibits symmetrical distribution, suggesting balanced enlargement contraction. Numerous vortices far exhibit clear periodic oscillation behavior resembling Kármán-like pattern. Furthermore, as increases, frequency rises gradually well forward shift high-strength interaction, while width near narrows. spanwise vorticity over time proper orthogonal decomposition modes confirm alternating shedding pattern akin Kármán streets.

Language: Английский

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The height ratio effects on the flow characteristics of a wall-mounted hemisphere immersed in the turbulent boundary layer

Ocean Engineering, Journal Year: 2024, Volume and Issue: 310, P. 118592 - 118592

Published: July 3, 2024

Language: Английский

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A novel approach to the control of vortex shedding downstream of a circular cylinder by control rod

Ocean Engineering, Journal Year: 2024, Volume and Issue: 317, P. 120010 - 120010

Published: Dec. 16, 2024

Language: Английский

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