On the streamwise vorticity generation and distribution in an angular particle wake

Article Engineering, Chemical

High fidelity adaptive Cartesian octree grid computations of the flow past a Platonic to a number of 200

Guodong Gai et al.

Summary: In this study, a high fidelity non-boundary fitted Distributed Lagrange Multiplier/Fictitious Domain method is used on an adaptive Cartesian octree grid to investigate the unbounded flow of a Newtonian fluid past a stationary Platonic polyhedron. The impact of angularity on the drag and lift coefficients is explored for a range of Reynolds numbers, and the effects of different angular positions of the polyhedron on these coefficients are discussed. The study also evaluates the accuracy of various non-spherical particle drag coefficient correlations available in the literature and provides new insights into the understanding of unbounded laminar flows past a non-spherical angular particle.

POWDER TECHNOLOGY (2023)

Add to Collection

Article Mechanics

Vorticity generation and conservation on generalised interfaces in three-dimensional flows

S. J. Terrington et al.

Summary: This article presents a three-dimensional theory of vorticity creation on generalised interfaces, including both non-slip and free-slip boundaries. Vorticity can be created on a boundary by the inviscid relative acceleration between fluid elements on each side of the boundary, driven by either tangential pressure gradients or body forces. Viscosity acts to transfer circulation between the vortex sheet representing the slip velocity on the interface, and the fluid interior, but is not responsible for the creation of vorticity on the interface. This formulation also describes a principle of vorticity conservation for interfacial and free-surface flows.

JOURNAL OF FLUID MECHANICS (2022)

Add to Collection

Article Computer Science, Interdisciplinary Applications

A fictitious domain method with distributed Lagrange multipliers on adaptive quad/octrees for the direct numerical simulation of particle-laden flows

Can Selcuk et al.

Summary: This article extends the DLM/FD method to quadtree/octree adaptive grids, aiming to improve accuracy and efficiency through dynamic local mesh refinement. The adaptive algorithm is implemented on the Basilisk platform and tested on various flow configurations for validation.

JOURNAL OF COMPUTATIONAL PHYSICS (2021)

Add to Collection

Article Mechanics

The generation and diffusion of vorticity in three-dimensional flows: Lyman's flux

S. J. Terrington et al.

Summary: Lyman's proposed definition of the boundary vorticity flux offers conceptual benefits in describing the transfer of circulation across a boundary, extending to three-dimensional flows, and enabling control-surface analysis. The definition also illustrates how the kinematic condition of vortex lines not ending in the fluid is maintained, providing an elegant description of viscous processes like vortex reconnection. The examination of flow over a sphere using Lyman's definition demonstrates the benefits of the proposed framework in understanding vortical flow dynamics.

JOURNAL OF FLUID MECHANICS (2021)

Add to Collection

Article Mechanics

Wake transitions behind a cube at low and moderate Reynolds numbers

Qingrui Meng et al.

Summary: Numerical investigation on wake transitions behind an isolated cube revealed four different flow regimes and their evolution patterns. The study also identified the transition mechanisms between vortex shedding states and the critical Reynolds numbers for bifurcations to different regimes.

JOURNAL OF FLUID MECHANICS (2021)

Add to Collection

Review Mechanics