Secondary flow's influence on the comprehensive frictional interactions is negligible during this period of transition. The attainment of efficient mixing, characterized by low drag and a low, yet non-zero, Reynolds number, is anticipated to hold substantial interest. Part 2 of the Taylor-Couette and related flows theme issue is dedicated to this article; it also marks the centennial of Taylor's seminal Philosophical Transactions paper.
Numerical studies and experimental analyses of the axisymmetric, wide-gap spherical Couette flow include noise considerations. 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. Flows of viscous, incompressible fluids are a result of either the rotation of only the interior sphere, or of both spheres rotating together. Additive noise was found to be instrumental in the generation of mean flow. Under specific circumstances, a greater relative amplification of meridional kinetic energy was detected in comparison to its azimuthal counterpart. Laser Doppler anemometer readings were used to verify the calculated flow velocities. For a deeper understanding of the swift growth of meridional kinetic energy in flows influenced by altering the co-rotation of the spheres, a model is presented. 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. Approaching the critical Reynolds number, a local minimum in the mean flow generation was demonstrably seen, corroborating theoretical predictions. This article within the theme issue 'Taylor-Couette and related flows' (part 2) marks the one-hundredth anniversary of Taylor's distinguished Philosophical Transactions paper.
The experimental and theoretical research on Taylor-Couette flow, which is driven by astrophysical interests, is reviewed succinctly. Differential rotation of interest flows, faster in the inner cylinder than the outer, safeguards against Rayleigh's inviscid centrifugal instability, exhibiting linear stability. Nonlinear stability is observed in quasi-Keplerian hydrodynamic flows at shear Reynolds numbers exceeding [Formula see text], wherein any turbulence is solely a result of interactions with the axial boundaries, not the radial shear. learn more While direct numerical simulations concur, they are presently unable to achieve such high Reynolds numbers. Radial shear-driven turbulence in accretion disks does not appear to derive solely from hydrodynamic mechanisms. The theory postulates linear magnetohydrodynamic (MHD) instabilities, chief among them the standard magnetorotational instability (SMRI), present in astrophysical discs. The low magnetic Prandtl numbers of liquid metals create a significant impediment to the successful execution of MHD Taylor-Couette experiments designed for SMRI. Maintaining high fluid Reynolds numbers, while carefully managing axial boundaries, is vital. 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. Outstanding inquiries within astrophysics, along with foreseen future trajectories, are evaluated, particularly concerning their mutual impact. Part 2 of the theme issue, 'Taylor-Couette and related flows on the centennial of Taylor's seminal Philosophical Transactions paper', contains this article.
From the perspective of chemical engineering, this study undertook a combined numerical and experimental investigation of the thermo-fluid dynamics of Taylor-Couette flow, considering an axial temperature gradient. An experimental Taylor-Couette apparatus was employed, characterized by a jacket that was divided vertically into two halves. A flow visualization and temperature measurement analysis of glycerol aqueous solutions at differing concentrations yielded a classification of flow patterns into six modes: heat convection dominant (Case I), alternating heat convection-Taylor vortex flow (Case II), Taylor vortex dominant (Case III), fluctuating Taylor cell structure maintenance (Case IV), Couette flow and Taylor vortex flow segregation (Case V), and upward motion (Case VI). 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. Furthermore, numerical simulations indicated that, in Case II, the introduction of heat convection into the Taylor-Couette flow resulted in enhanced heat transfer. Subsequently, the average Nusselt number achieved with the alternative flow exceeded that observed with the stable Taylor vortex flow. Consequently, the interplay of heat convection and Taylor-Couette flow proves a potent mechanism for boosting 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.
Our approach utilizes direct numerical simulation to model the Taylor-Couette flow within a dilute polymer solution, focusing on moderate system curvature and the rotational motion of only the inner cylinder. This particular configuration is elaborated in [Formula see text]. Modeling polymer dynamics relies on the finitely extensible nonlinear elastic-Peterlin closure. Rotating waves, revealed by simulations, exhibit novel elasto-inertial properties, displaying arrow-shaped polymer stretch patterns aligned with the streamwise direction. high-biomass economic plants The rotating wave pattern is investigated in depth, and its dependence on the dimensionless Reynolds and Weissenberg numbers is explicitly analyzed. Newly identified within this study are diverse flow states showcasing arrow-shaped structures in tandem with other structural forms, a summary of which follows. Part 2 of the special issue on Taylor-Couette and related flows, in celebration of the centennial of Taylor's original Philosophical Transactions article, includes this article.
Taylor's 1923 paper, appearing in the Philosophical Transactions, offered profound insights into the stability of the flow pattern now termed Taylor-Couette flow. Taylor's seminal linear stability analysis of fluid flow between rotating cylinders, published a century ago, has profoundly shaped the field of fluid mechanics. The paper's impact has been felt across general rotating flows, encompassing geophysical and astrophysical flows, as well as its critical role in securing the acceptance of several fundamental fluid mechanics concepts. This two-part publication features a compilation of review and research articles, exploring an extensive spectrum of contemporary research topics, all deeply rooted in Taylor's landmark paper. Within the broader context of the 'Taylor-Couette and related flows on the centennial of Taylor's seminal Philosophical Transactions paper (Part 2)' theme issue, this article is situated.
Taylor-Couette flow instability research, stemming from G. I. Taylor's seminal 1923 study, has profoundly impacted subsequent endeavors, thereby laying the groundwork for exploring and characterizing complex fluid systems that demand a precisely managed hydrodynamics setting. To examine the mixing dynamics of intricate oil-in-water emulsions, a TC flow system with radial fluid injection is used in this work. A concentrated emulsion, mimicking oily bilgewater, is injected radially into the annulus between the rotating inner and outer cylinders, allowing it to disperse within the flow field. Through the investigation of the mixing dynamics resultant from the process, effective intermixing coefficients are established by assessing changes in the intensity of light reflected from emulsion droplets in fresh and saltwater samples. Emulsion stability's response to the flow field and mixing conditions is documented by observing changes in droplet size distribution (DSD); further, the employment of emulsified droplets as tracer particles is discussed concerning alterations in the dispersive Peclet, capillary, and Weber numbers. For oily wastewater systems, the formation of larger droplets, a key factor in efficient separation, is observed to be correlated with water treatment processes, and the final droplet size distribution (DSD) is demonstrably adjustable by varying salt concentration, observation duration, and mixing regime within the TC 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. The subjects, and.
The ICF-TINI, consisting of 15 items derived from the ICF's body function and activity domains, was utilized in this cross-sectional study. Chronic tinnitus affected 137 participants in our study. Using confirmatory factor analysis, the two-structure framework including body function, activities, and participation received validation. Assessment of model fit involved a comparison of chi-square (df), root mean square error of approximation, comparative fit index, incremental fit index, and Tucker-Lewis index fit values against the recommended fit criteria. Avian biodiversity Internal consistency reliability was evaluated using Cronbach's alpha.
Two structures within the ICF-TINI were supported by the fit indices, and the factor loading values further corroborated the appropriate fit of each individual 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.