The frictional dynamics, during this stage of transition, are largely unaffected by the contribution of secondary flows. The aim of attaining efficient mixing at low drag, and at a low but finite Reynolds number, is anticipated to generate considerable interest. This theme issue's second installment, dedicated to Taylor-Couette and related flows, marks a century since Taylor's pivotal Philosophical Transactions paper.
Noise is incorporated into numerical simulations and experiments on axisymmetric, wide-gap spherical Couette flow. These types of studies are crucial since the majority of natural processes are subject to random fluctuations. Noise is a consequence of introducing time-random fluctuations with zero mean into the rotational motion of the inner sphere, thus affecting the flow. Incompressible, viscous fluid movement results from either the rotation of the inner sphere alone, or from the simultaneous rotation of both spheres. Mean flow generation was observed as a consequence of the presence of additive noise. A disproportionately higher relative amplification of meridional kinetic energy, compared to the azimuthal component, was also observed under specific conditions. Measurements from a laser Doppler anemometer corroborated the predicted flow velocities. A model is presented to clarify the swift increase in meridional kinetic energy observed in flows that result from altering the co-rotation of the spheres. The linear stability analysis of the flows generated by the inner sphere's rotation unveiled a reduction in the critical Reynolds number, coinciding with the start of the first instability. As the Reynolds number approached its critical value, a local minimum in mean flow generation was noted, harmonizing with the existing theoretical framework. The 'Taylor-Couette and related flows' theme issue, part 2, features this article, which commemorates the centennial of Taylor's landmark Philosophical Transactions paper.
A review of Taylor-Couette flow, based on astrophysical considerations, encompassing both experimental and theoretical approaches, is provided. Interest flows display differing rotational speeds; the inner cylinder's speed exceeds that of the outer, ensuring linear stability against Rayleigh's inviscid centrifugal instability. At shear Reynolds numbers reaching [Formula see text], the hydrodynamic flows of this quasi-Keplerian type demonstrate nonlinear stability; no turbulence is observed that cannot be attributed to interactions with the axial boundaries, rather than the inherent radial shear. INDY inhibitor datasheet Direct numerical simulations, though in agreement, are currently limited in their capacity to reach these exceptionally high Reynolds numbers. This outcome points to the non-exclusively hydrodynamic nature of accretion disc turbulence, especially as influenced by radial shear. Astrophysical discs, according to theory, are prone to linear magnetohydrodynamic (MHD) instabilities, most notably the standard magnetorotational instability (SMRI). Liquid metal MHD Taylor-Couette experiments targeted at SMRI are hampered by the low magnetic Prandtl numbers. The achievement of high fluid Reynolds numbers, along with meticulous control of axial boundaries, is paramount. The ongoing efforts in the field of laboratory SMRI research have led to the identification of some intriguing non-inductive analogs of SMRI, and the successful implementation of SMRI utilizing conducting axial boundaries, as recently reported. Astrophysics' significant unanswered questions and upcoming potential, particularly their close relationships, are meticulously discussed. The 'Taylor-Couette and related flows' theme issue, part 2, features this article, which commemorates the centennial of Taylor's landmark Philosophical Transactions paper.
This study, approached from a chemical engineering viewpoint, used experimental and numerical methods to examine the thermo-fluid dynamics of Taylor-Couette flow under an axial temperature gradient. The Taylor-Couette apparatus, incorporating a jacket split vertically into two parts, was instrumental in the experiments. Glycerol aqueous solutions of varying concentrations, as observed through flow visualization and temperature measurements, exhibit six distinct flow patterns: Case I (heat convection dominant), Case II (alternating heat convection-Taylor vortex), Case III (Taylor vortex dominant), Case IV (fluctuating Taylor cell structure), Case V (segregation of Couette and Taylor vortex flows), and Case VI (upward motion). The Reynolds and Grashof numbers were used to categorize these flow modes. The concentration-dependent flow patterns observed in Cases II, IV, V, and VI mark a transition zone between Cases I and III. Case II numerical simulations highlighted that heat convection within the altered Taylor-Couette flow facilitated enhanced heat transfer. The alternative flow demonstrated a higher average Nusselt number compared to the stable Taylor vortex flow. Ultimately, the correlation between heat convection and Taylor-Couette flow constitutes a remarkable approach to improve heat transfer. This article is included in the 'Taylor-Couette and related flows' centennial theme issue, part 2, and honours the centennial of Taylor's pivotal work in Philosophical Transactions.
Polymer solutions' Taylor-Couette flow, under the scenario of inner cylinder rotation in a moderately curved system, is numerically simulated directly. The specifics are detailed in [Formula see text]. Employing the finitely extensible nonlinear elastic-Peterlin closure, a model of polymer dynamics is constructed. The existence of a novel elasto-inertial rotating wave, exhibiting arrow-shaped polymer stretch field structures oriented in the streamwise direction, has been confirmed by the simulations. immune restoration A comprehensive analysis of the rotating wave pattern is presented, including its dependence on the dimensionless Reynolds and Weissenberg numbers. The initial discovery in this study of coexisting arrow-shaped structures in various flow states, along with other structures, warrants brief discussion. Marking the centennial of Taylor's groundbreaking Philosophical Transactions paper on Taylor-Couette and related flows, this article forms part two of the dedicated issue.
A significant contribution by G. I. Taylor, published in the Philosophical Transactions in 1923, elucidated the stability of the hydrodynamic configuration now identified as Taylor-Couette flow. Taylor's linear stability analysis of fluid flow between rotating cylinders, a landmark study published a century ago, has had an immense effect on the field of fluid mechanics. The paper's reach extends to encompass general rotating flows, along with geophysical and astrophysical flows, its importance further underlined by the firm establishment of several core concepts within fluid mechanics, now broadly accepted. The dual-part issue consolidates review and research articles, examining a broad spectrum of contemporary research topics, all underpinned by Taylor's groundbreaking publication. 'Taylor-Couette and related flows on the centennial of Taylor's seminal Philosophical Transactions paper (Part 2)' is the theme of this featured article.
Inspired by G. I. Taylor's 1923 research on Taylor-Couette flow, numerous studies have investigated and described these flow instabilities, thus establishing a robust foundation for investigations into the intricate mechanics of fluid systems requiring a strictly controlled hydrodynamic environment. A radial fluid injection method coupled with a TC flow system is employed in this study to examine the mixing characteristics of complex oil-in-water emulsions. Oily bilgewater-simulating concentrated emulsion is injected radially into the annulus formed by the rotating inner and outer cylinders, where it disperses throughout the flow field. The resultant mixing dynamics are explored thoroughly, and efficient intermixing coefficients are determined via the measurements of light reflection intensity from emulsion droplets in fresh and salty water solutions. Emulsion stability's response to flow field and mixing conditions is monitored by droplet size distribution (DSD) changes, and the use of emulsified droplets as tracers is examined in relation to modifications in dispersive Peclet, capillary, and Weber numbers. In the context of oily wastewater treatment, the formation of larger droplets promotes better separation, and the measured droplet size distribution is demonstrably affected by the salt concentration, the duration of observation, and the mixing flow conditions within the test cell. This article forms part two of the themed issue 'Taylor-Couette and related flows,' marking a century since Taylor's influential Philosophical Transactions paper.
This research documents the creation of an ICF-based tinnitus inventory (ICF-TINI), which measures the impact tinnitus has on a person's function, activities, and societal participation as per the International Classification of Functioning, Disability, and Health. Subjects and,.
A cross-sectional study design made use of the ICF-TINI, consisting of 15 items originating from the ICF's two domains: body function and activities. Within our study, a group of 137 respondents experienced persistent tinnitus. The two-structure framework (body function, activities, and participation) was validated through confirmatory factor analysis. To determine the model's fit, values for chi-square (df), root mean square error of approximation, comparative fit index, incremental fit index, and Tucker-Lewis index were assessed against the suggested fit criteria. immune priming To determine the internal consistency reliability, Cronbach's alpha was employed.
The fit indices corroborated the existence of two distinct structures within the ICF-TINI, whereas the factor loading values illuminated the suitability of each item. The internal TINI of the ICF demonstrated a high degree of consistency in its reliability, achieving a score of 0.93.
Tinnitus's influence on a person's physical abilities, daily activities, and social engagement is rigorously and accurately assessed via the ICFTINI, a reliable and valid tool.