This study gives insights into the interfacial instabilities of a ventilation cavity by injecting gas vertically horizontal liquid crossflow through both numerical and experimental investigations. We identified four distinct regimes based on their topological characteristics: (I) discrete bubble, (II) continuous cavity, (III) bifurcated (IV) bubble plume. The boundaries for these are delineated within parameter space velocity jet speed. A comprehensive analysis flow characteristics...

The present study employs a two-way coupled multi-scale method to simulate and analyze the cloud cavitation flow around hydrofoil, based on which distribution of erosion risk hydrofoil is evaluated. numerical results demonstrate that can capture not only overall evolution characteristics but also generation, growth, collapse small-scale bubbles. Throughout majority cycle, scale Lagrange bubbles roughly follows logarithmic Gaussian distribution. However, it shows double-peak characteristic as...

Two-dimensional direct numerical simulation and Floquet stability analysis have been performed at moderate Keulegan–Carpenter number ( $KC$ ) low Reynolds $Re$ for a square cross-section cylinder with its face normal to the oscillatory flow. Based on simulations map of flow regimes is formed compared around an oscillating circular by Tatsuno & Bearman J. Fluid Mech. , vol. 211, 1990, pp. 157–182). Two new observed, namely A $^{\prime }$ F . The regime found characterised transverse...

This study investigates the influence of rheological parameters on unyielded zone, pressure drop, and secondary flow pattern non-Newtonian fluid like fresh cement mortar through a pipe bend with different curvatures. The regularized Herschel–Bulkley model is employed in framework lattice Boltzmann method to effects visco-plastic shear-thickening/thinning characteristics variations yielding stress σ0 power-law index n. sharper curvature, higher contributes smaller more asymmetric zone even...

The flow-induced vibration of a two-degree-of-freedom cylinder near free surface at low Reynolds number (Re = 200) is numerically investigated using the lattice Boltzmann method and free-surface model. effects Froude submergence depth on characteristics flow field are discussed. With approach surface, wake behind interacts with resulting in switch vortex shedding mode fluctuation which turn affects cylinder. Additionally, decrease normalized h ∗ results transverse amplitude an increase...

Three-dimensional (3-D) wake transitions of a steady flow past two side-by-side circular cylinders are investigated through Floquet analysis and direct numerical simulations (DNS) over the gap-to-diameter ratio $g^*$ up to 3.5 Reynolds number ${\textit {Re}}$ 400. When flows behind form in-phase anti-phase wakes at large , transition is similar isolated cylinder counterpart, with critical for onset 3-D ( {Re}}_{cr-1}$ ) happens around 180. At small becomes interestingly complex due distinct...

Oscillatory flow around a circular cylinder close to plane boundary is numerically investigated at low-to-intermediate Keulegan–Carpenter ( $KC$ ) and Stokes numbers $\unicode[STIX]{x1D6FD}$ for different gap-to-diameter ratios $e/D$ ). A set of unique regimes observed classified based on the established nomenclature in $KC,\unicode[STIX]{x1D6FD}$ )-space. It found that not only influenced by but also ratio thickness layer $\unicode[STIX]{x1D6FF}$ gap size e At relatively large...

Oscillatory flow around a cluster of four circular cylinders in diamond arrangement is investigated using two-dimensional direct numerical simulation over Keulegan–Carpenter numbers ( KC ) ranging from 4 to 12 and Reynolds Re 40 230 at gap-to-diameter ratios G 0.5, 1, 2 4. Three types flows, namely synchronous, quasi-periodic desynchronized flows (along with 14 regimes) are mapped out the , )-parameter space. The observed characteristics show few unique features that absent square reported...

The present work experimentally studied the coupled interaction between fracture of an ice plate floating on water surface, induced by pulsation a high-pressure bubble, and associated deformation vertically submerged aluminum plate. dynamic behaviors bubbles fractured were concurrently recorded using two high-speed cameras, plastic was measured ultra-depth three-dimensional microscope. results indicated that jet direction collapsed bubble is heavily influenced position to generate due...

This paper focuses on the characteristics of regime C flow (Tatsuno & Bearman, J. Fluid Mech. , vol. 211, 1990, pp. 157–182) around an oscillating circular cylinder in still water. The is characterised by formation large-scale vortex cores arranged as opposed von Kármán streets, resulting from a regular switching shedding directions with respect to axis oscillation. Both Floquet analysis and direct numerical simulations (DNS) are performed investigate two- (2-D) three-dimensional (3-D)...

Bistabilities of two equilibrium states discovered in the coupled side-by-side Kármán wakes are investigated through Floquet analysis and direct numerical simulation (DNS) with different initial conditions over a range gap-to-diameter ratio ( $g^*= 0.2\text {--}3.5$ ) Reynolds number $Re = 47\text {--}100$ ). Two bistabilities found transitional $g^*-Re$ regions from in-phase (IP) to anti-phase (AP) vortex shedding states. By initialising flow DNS zero conditions, first bistable region (i.e....

This paper presents a numerical investigation of oscillatory flow around circular cylinder that is placed in proximity to plane boundary parallel the axis. The onset and development Honji instability are studied over range Stokes numbers ( $\unicode[STIX]{x1D6FD}$ ) gap-to-diameter ratios $e/D$ at fixed Keulegan–Carpenter number $KC=2$ ). Four regimes identified $e/D,\unicode[STIX]{x1D6FD}$ )-plane: (I) featureless two-dimensional flow, (II) stable vortex, (III) unstable vortex (IV) chaotic...

Impulse waves generated by subaerial landslides of a block model along frictionless surface are investigated numerically based on combination immersed boundary method and lattice Boltzmann method. A wave propagation is proposed through machine learning. The observed impulse classified into Stokes-like waves, solitary-like cnoidal-like bore-like waves. influence the slope angle slide front generation from perspectives quantitative analyses primary amplitude energy transformation. release,...

The coexistence of density stratification and surface tension alters the dynamic behaviors two-phase immiscible wake jet flows in complex interfacial instability modes. Building on framework established by Schmidt et al. [“Global stability nonlinear dynamics with a two-fluid interface,” J. Fluid Mech. 915, A96 (2021)], we conduct global analysis to investigate effects ratio instabilities planar flows. Surface tension, acting counterintuitively as either stabilizer or destabilizer, enhances...