Search

The mutual influences of the electric field, rotation, and heat transmission find applications in controlled drug delivery systems, precise microfluidic manipulation, and advanced materials' processing techniques due to their ability to tailor fluid behavior and surface morphology with enhanced precision and efficiency. Capillary instability has widespread relevance in various natural and industrial processes, ranging from the breakup of liquid jets and the formation of droplets in inkjet printing to the dynamics of thin liquid films and the behavior of liquid bridges in microgravity environments. This study examines the swirling impact on the instability arising from the capillary effects at the boundary of Rivlin–Ericksen and viscous liquids, influenced by an axial electric field, heat, and mass transmission. Capillary instability arises when the cohesive forces at the interface between two fluids are disrupted by perturbations, leading to the formation of characteristic patterns such as waves or droplets. The influence of gravity and fluid flow velocity is disregarded in the context of capillary instability analyses. The annular region is formed by two cylinders: one containing a viscous fluid and the other a Rivlin–Ericksen viscoelastic fluid. The Rivlin–Ericksen model is pivotal for comprehending the characteristics of viscoelastic fluids, widely utilized in industrial and biological contexts. It precisely characterizes their rheological complexities, encompassing elasticity and viscosity, critical for forecasting flow dynamics in polymer processing, food production, and drug delivery. Moreover, its applications extend to biomedical engineering, offering insights crucial for medical device design and understanding biological phenomena like blood flow. The inside cylinder remains stationary, and the outside cylinder rotates at a steady pace. A numerically analyzed quadratic growth rate is obtained from perturbed equations using potential flow theory and the Rivlin–Ericksen fluid model. The findings demonstrate enhanced stability due to the heat and mass transfer and increased stability from swirling. Notably, the heat transfer stabilizes the interface, while the density ratio and centrifuge number also impact stability. An axial electric field exhibits a dual effect, with certain permittivity and conductivity ratios causing perturbation growth decay or expansion. [ABSTRACT FROM AUTHOR]

The multifaceted applications of swirling interfaces featuring heat and mass transfer extend across diverse industries, encompassing energy, manufacturing, healthcare, and environmental protection. The present study is concerned with examining the swirling impact on the capillary instability occurring at the interface between a Walter's B viscoelastic fluid and a viscous fluid, under the influence of heat and mass transfer. The setup consists of two rigid cylinders that form an annular region filled with viscous fluid on the inner side and Walter's B viscoelastic fluid on the outer side. The outer cylinder rotates at a constant angular velocity, while the inner cylinder remains stationary. The study employs the Walter's B viscoelastic model, which conforms to the potential flow theory for viscoelastic fluids. The proposed flow theory disregards tangential stresses and balances the difference in normal viscous stresses with the surface force at the free boundary. The perturbed equations yield a quadratic equation in growth rate, which is numerically analyzed. The results show that heat and mass transfer enhance the interface's stability and swirling makes it more stable. Moreover, it is noteworthy that the Weber number exerts a stabilizing influence on the interface, while the density ratio also plays a role in promoting its stability. The centrifuge number exhibits a counteractive effect by impeding interface growth, thus contributing to its stabilization. [ABSTRACT FROM AUTHOR]

In this inspection, the control of the magnetic power on the onset of Casson fluid convection formed by purely inner warming in a porous medium layer is examined. The modified Darcy model is employed to designate the rheological arrival of Casson liquid flow in a porous matrix. Two types of thermal boundaries are exploited, namely, type (I) both isothermal and type (II) lower insulated and top isothermal boundaries. Using the linear stability inspection and Galerkin technique, the approximate analytical solution and numerical solution correct to one decimal place are offered. It is detected that for type (I) boundary conditions, the convective wave concentrates in the upper layer if it occurs, whereas for type (II) boundary conditions, it emphases in the whole layer. The magnetic Chandrasekhar number postpones the convection movement while the Casson constraint accelerates it. The facet of the convective cells drops with enhancing the magnetic strength and the Casson constraint. In the absenteeism of magnetic field, the Casson constraint has no regulation on the dimension of convective cells. It is also found that the presented analytical result with two term Galerkin process has overall 5% error, while with one term Galerkin process the error was overall 19%. [ABSTRACT FROM AUTHOR]

The interface of a viscous fluid and A l 2 O 3 -water nanofluid is analyzed through linear instability analysis in a spherical configuration. The viscous fluid lies inside the sphere while the outside region contains nanofluid. In this model, the viscosity of the nanofluid is considered a function of the base fluid viscosity, nanoparticles volume fraction, fractal aggregates, and nanoparticles shape. The perturbed flow is taken as irrotational, and the linear perturbation equations are solved through viscous irrotational theory. The perturbations growth rate can be computed through a 2-degree polynomial and the coefficients of this polynomial are the functions of the Atwood number, Richardson number, Weber number, Reynolds number, etc. The nanofluid interface is found more stable than the viscous fluid interface. The density of nanofluids raises the amplitude of disturbances while the nanofluid's viscosity has a reverse effect. [ABSTRACT FROM AUTHOR]

The thermohydraulic performance (THP) of a solar air heater (SAH) duct with staggered D‐shaped ribs as roughness geometry is examined in this work using three‐dimensional numerical investigation. The investigation is carried out at roughness parameters of radius of rib to transverse pitch (r/Ptv) ratios of 0.1–0.35 and longitudinal pitch to radius of rib (Plg/r) ratios of 4–10 under varied operating circumstances of Reynolds number (Re) from 10,200 to 20,200. The maximum Nusselt number (Nu) is obtained to be 81.3 at Re of 20,200, r/Ptv as 0.1, and Plg/r as 4. In contrast, the maximum friction factor (f) is obtained to be 0.0169 at Re of 10,200, r/Ptv as 0.35, and Plg/r as 4. In the range of parameters examined, the maximum enhancement in Nusselt number (Nu/Nus) is observed to be 1.35 at an optimal parameter of r/Ptv as 0.1, Plg/r as 4, and Re as 10,200. Correspondingly, the enhancement in the friction factor (f/fs) at this optimum parameter is 1.87. The maximum value of the THP parameter is found to be 1.1 at the same optimum range of parameters. In further analysis, correlations were developed for Nusselt number (Nu) and friction factor (f) in terms of r/Ptv, Plg/r, and Re with a deviation of ±2% and ±1.5%, respectively. [ABSTRACT FROM AUTHOR]

This article investigates the effects of Atwood numbers on the flow physics of shock-driven elliptical gas inhomogeneity based on numerical simulations. We examine five different gases--He, Ne, Ar, Kr, and SF6--that are filled inside an elliptical bubble and surrounded by N2 in order to study flow physics. A high-order modal discontinuous Galerkin finite element approach is used to solve compressible Euler equations for all numerical simulations. In terms of validation studies, the numerical outcomes match the existing experimental data quite well. The findings show that the Atwood number has a significant impact on the characteristics of flow, including wave patterns, the development of vortices, the generation of vorticity, and bubble deformation. When the value of At is greater than zero i.e. At > 0, there is a notable divergence between the incident wave outside the bubble and the transmitted shock wave inside the bubble. Complex wave patterns, including reflected and newly transmitted shock, are seen during the encounter. Interestingly, the transmitted shock and incident shock waves move with the same rates at At = 0. While, compared to the incident shock wave, the transmitted shock wave moves more quickly for At < 0. The influence of Atwood number is then investigated in depth by looking at the vorticity production at the elliptical interface. Furthermore, in the analysis of vorticity production processes, the important spatial integrated domains of average vorticity, dilatational and baroclinic vorticity production terms, and evolution of enstrophy are extended. Finally, a quantitative research based on the interface qualities delves deeply into the influence of the Atwood number on the flow mechanics. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of viscous fluids and a Rivlin–Ericksen (R‐E) viscoelastic fluid interface under the influence of heat and mass transfer, while both fluids are exposed to an axial electric field. The fluids are restricted within an annular region that is enclosed by two rigid cylinders. The outer section of the annular region holds the R‐E viscoelastic fluid, while the inner section is filled with the viscous fluid. To ascertain the correlation between perturbation growth and wavenumber, the theory of potential flow on viscoelastic–viscous fluids is applied, and the result is represented as a second‐order polynomial. This correlation is numerically solved using the Newton–Raphson method. Variables of viscous flow, such as electric field strength, heat transfer coefficient, viscoelasticity, viscosity, and so forth, are numerically studied. With an increase in electric field strength, the perturbation growth decays and expands for the particular combinations of permittivity and conductivity ratio, showing the dual effect of the axial electric field. [ABSTRACT FROM AUTHOR]

The anaerobic digestion (AD) disposal of stover and cattle manure is of great significance to the development of lowcarbon economy and green energy in China, but it will also have an impact on the environment, and the degree of influence is different for various raw materials. In this study, life cycle assessment (LCA) methods were applied to analyze and compare the impact of corn stovers biogas projects (CSBP) and dairy manure biogas projects (DMBP) on the environment during the whole operation stage. The results of inventory analysis were evaluated by ReCiPe2016 Hierarchy(H) mid-point (problem-oriented) and end-point (destruction-oriented) method, respectively. The results showed that the net energy efficiency of CSBP was higher (763.903 kW·h/FU) and the greenhouse gas (GHG) emission reduction of DMBP was more (5541.418 kg CO2-eq/FU). The anaerobic digestion (AD) units have the greatest environmental impacts, and human carcinogenic toxicity is the largest environmental impact category (1.16-1.43 PE). The key to reducing environmental impact is reducing the input of chemical substances and the waste of electric energy. Both CSBP and DMBP have a favorable impact on ecosystem quality and resources, and CSBP is more beneficial to the environment (-10.297 Pt). Co-digestion is an important measure to reduce the environmental damage from biogas projects. These research results provide theoretical support for the selection of raw materials for large-scale biogas projects in China, provide technical basis for reducing the impact of actual operation on the environment, and promote the resource utilization of agricultural waste and carbon dioxide emission reduction and sequestration. [ABSTRACT FROM AUTHOR]