Interpenetrating spiral vortices and other coexisting states in suspension Taylor-Couette flow

Particle-laden Taylor–Couette flows: higher-order transitions and evidence for azimuthally localized wavy vortices

“…2018; Ramesh et al. 2019; Ramesh & Alam 2020), including the present work, is that particles are homogeneously distributed.…”

“…circumvent this conundrum altogether by sticking to a ramp-down protocol, as they observed migration of particles towards the axial boundaries (see § 3.2 of their article) in the event of following a ramp-up protocol. Moreover, a common assumption in all relevant experiments Ramesh et al 2019;Ramesh & Alam 2020), including the present work, is that particles are homogeneously distributed. Shown in figure 8 is a contour plot of times needed for a homogeneous suspension to settle/rise by one gap width of the annulus, in a finite container.…”

“…Similar observations are visible in the experiments of Ramesh et al (2019), where their ramp-up experiments yielded the coexisting states, while the ramp-down experiments did not (see figures 5, 12-14 in their article). An exception to this trend was found in the experiments of Ramesh & Alam (2020) who reported axially segregated states in their ramp-down experiments too. circumvent this conundrum altogether by sticking to a ramp-down protocol, as they observed migration of particles towards the axial boundaries (see § 3.2 of their article) in the event of following a ramp-up protocol.…”

“…(2019) extended on this by also considering an experimental protocol with increasing inertia, which gave rise to the so-called ‘coexisting states’ (presence of axially segregated flow states, such as the combination of wavy and Taylor vortices or Taylor and spiral vortices). More recently, Ramesh & Alam (2020) also reported the existence of interpenetrating spiral vortices in such flows.…”

Symmetry-breaking bifurcations and hysteresis in compressible Taylor–Couette flow of a dense gas: a molecular dynamics study

“…More recently, experiments on suspension TCF (Majji, Banerjee & Morris 2018; Ramesh, Bharadwaj & Alam 2019; Ramesh & Alam 2020) have unveiled a variety of new patterns in addition to WTVs. Ramesh et al (2019) showed that the radial segregation of particles led to shear-band-type profiles for the azimuthal velocity, which are responsible for the non-monotonic variations of the angular momentum along the radial direction.…”