Channel Contraction Research Articles

Financial Sector Reforms and Inflation-Growth Nexus

In the 1980s, Pakistan's financial reforms reduced central bank borrowing, raising government debt and tax collection needs. In this context, the conventional approach to evaluating the costs and benefits of low inflation proves inadequate. The sacrifice ratio (SR) focuses on demand contraction's impact on economic activity and fails to capture the true costs of inflation by overlooking the supply-side effects of reduced fiscal space. This study re-evaluates the SR, accounting for both the demand contraction channel and the long-term supply side impact of diminished fiscal space. We hypothesize that the cumulative costs outweigh the long-term benefits of price stability. By incorporating fiscal space scenarios into the time-series model for SR estimation; our results indicate an SR approximately double that found in earlier studies. These findings highlight the importance of incorporating fiscal implications into monetary policy decisions to support sustainable economic growth.

Numerical Analysis of Shockwave Dynamics in Contraction Channels

Numerical Analysis of Shockwave Dynamics in Contraction Channels

Energy Characteristics in the Flow Channel of the Shaft-Type Tubular Pumping Station Considering Tides

The shaft-type tubular pumping station has the remarkable characteristics of a large flow rate and high efficiency. It can realize the functions of irrigation, pumping, and drainage through pumping and generating conditions considering tides. Moreover, it is widely used in the plain area of eastern China and the tidal area along the marine region. Due to the different topological features of the airfoil of the impeller, the energy evolution characteristics of the shaft-type tubular pumping station during pumping and generating conditions remain unclear. The entropy generation theory was introduced to numerically simulate the flow pattern and energy characteristics in the shaft-type channel, impeller, and straight channel in operation conditions. The results show that the flow pattern is stable when the shaft-type channel and the straight-type channel are used as the inlet channel under pumping and generating conditions, and a low-pressure region occurs in the contraction section of the shaft-type channel. The velocity of sections of the inlet and outlet and the middle section of the impeller in the generating condition is larger than that in the pumping condition. In addition, the difference in the static pressure on the blade surface nearby the hub is large. With a change in the position of the wingspan, the difference gradually decreases from the small flow condition to the large flow condition. There is a high-entropy production rate zone in the channel contraction section and the shaft-type wall surface of the shaft-type flow channel. When the straight-type channel is used as the outlet flow channel, a high-entropy production region appears near the inlet water surface. In the pumping condition, a high-entropy production area is found at the inlet of the impeller, the blade groove channel, and the inlet of the guide vane. In the generating condition, a high-entropy production area is found at the out-of-impeller outlet, the blade groove channel, and the outlet of the guide vane. These research achievements have some reference value for the design of the shaft-type tubular pumping station considering tides and the study of hydraulic performance, along with the energy characteristics of the channels.

Meteotsunamis in the Tamsui River estuary, Taiwan

This study presents meteotsunami evolution and statistics in the Tamsui River estuarine system from 12 years observations. In the tide-dominated estuary, a strong correlation is observed between high tidal levels and the upstream propagation of meteotsunami waves. Such long waves travel the Tamsui River at an average speed of 6 m/s, while their speed slightly decreases to 4 m/s in the upstream rivers. The propagation changes are likely due to the contraction channel and shallow depth of the upstream rivers. During the upstream propagation, low-frequency waves (an average period of 44.5 min) have the significantly low reduction of wave height compared to high-frequency waves (an average period of 21.5 min). Findings suggest that low-frequency waves are capable of propagating over longer distances within the river estuary than high-frequency waves. In terms of long-term statistical analysis in 2014–2020, meteotsunamis predominantly occur in late winter and early spring. These events are primarily triggered by cluster and frontal convective storms, which are predominant atmospheric forcings responsible for initiating meteotsunami waves. These convective storms are often associated with incoming cold surges or cold fronts crossing the Taiwan Strait, which has implications on the role of pressure and wind disturbances, as well as the resonance mechanism in meteotsunami initiation. Furthermore, the study assesses the probability of meteotsunami occurrences, revealing that an annual prediction of wave height can reach up to 0.3 m. This finding raises concerns regarding potential hazards in Taipei City, where the population exceeds 6.8 million people. Of particular concern is the vulnerability of the Keelung River, which flows through the city center. In summary, the potential hazards posed by meteotsunamis in the Tamsui River estuary underscore the importance of risk management and preparedness measures.

Nonlinear Phenomena of Fluid Flow in a Bioinspired Two-Dimensional Geometric Symmetric Channel with Sudden Expansion and Contraction

Inspired by the airway for phonation, fluid flow in an idealized model within a sudden expansion and contraction channel with a geometrically symmetric structure is investigated, and the nonlinear behaviors of the flow therein are explored via numerical simulations. Numerical simulation results show that, as the Reynolds number (Re = U0H/ν) increases, the numerical solution undergoes a pitchfork bifurcation, an inverse pitchfork bifurcation and a Hopf bifurcation. There are symmetric solutions, asymmetric solutions and oscillatory solutions for flows. When the sudden expansion ratio (Er) = 6.00, aspect ratio (Ar) = 1.78 and Re ≤ Rec1 (≈185), the numerical solution is unique, symmetric and stable. When Rec1 < Re ≤ Rec2 (≈213), two stable asymmetric solutions and one symmetric unstable solution are reached. When Rec2 < Re ≤ Rec3 (≈355), the number of numerical solution returns one, which is stable and symmetric. When Re > Rec3, the numerical solution is oscillatory. With increasing Re, the numerical solution develops from periodic and multiple periodic solutions to chaos. The critical Reynolds numbers (Rec1, Rec2 and Rec3) and the maximum return velocity, at which reflux occurs in the channel, change significantly under conditions with different geometry. In this paper, the variation rules of Rec1, Rec2 and Rec3 are investigated, as well as the maximum return velocity with the sudden expansion ratio Er and the aspect ratio Ar.

Phenotyping of single plant cells on a microfluidic cytometry platform with fluorescent, mechanical, and electrical modules.

Compared to animal cells, phenotypic characterization of single plant cells on microfluidic platforms is still rare. In this work, we collated population statistics on the morphological, biochemical, physical and electrical properties of Arabidopsis protoplasts under different external and internal conditions, using progressively improved microfluidic platforms. First, we analyzed the different effects of three phytohormones (auxin, cytokinin and gibberellin) on the primary cell wall (PCW) regeneration process using a microfluidic flow cytometry platform equipped with a single-channel fluorescence sensor. Second, we correlated the intracellular reactive oxygen species (ROS) level induced by heavy metal stress with the concurrent PCW regeneration process by using a dual-channel fluorescence sensor. Third, by integrating contraction channels, we were able to effectively discriminate variations in cell size while monitoring the intensity of intracellular ROS signaling. Fourth, by combining an electrical impedance electrode with the contraction channel, we analyzed the differences in electrical and mechanical properties of wild-type and mutant plant cells before and after primary cell wall regeneration. Overall, our work demonstrates the feasibility and sensitivity of microfluidic flow cytometry in high-throughput phenotyping of plant cells and provides a reference for assessing metabolic and physiological indicators of individual plant cells in multiple dimensions.

Verification of Three-dimensional Numerical Study of Scour in Channel, Sudden and Gradual Contractions using Experimental Data

Verification of Three-dimensional Numerical Study of Scour in Channel, Sudden and Gradual Contractions using Experimental Data

BKCa channels are involved in spontaneous and lipopolysaccharide-stimulated uterine contraction in late gestation mice†.

The large-conductance, voltage-gated, calcium (Ca2+)-activated potassium channel (BKCa) is one of the most abundant potassium channels in the myometrium. Previous work conducted by our group has identified a link between inflammation, BKCa channels and excitability of myometrial smooth muscle cells. Here, we investigate the role of BKCa channels in spontaneous and lipopolysaccharide (LPS)-stimulated uterine contraction to gain a better understanding of the relationship between the BKCa channel and uterine contraction in basal and inflammatory states. Uteri of C57BL/6J mice on gestational day 18.5 (GD18.5) were obtained and either fixed in formalin or used immediately for tension recording or isolation of primary myocytes for patch-clamp. Paraffin sections were used for immunofluorescenctdetection of BKCa and Toll-like receptor (TLR4). For tension recordings, LPS was administered to determine its effect on uterine contractions. Paxilline, a BKCa inhibitor, was used to dissect the role of BKCa in uterine contraction in basal and inflammatory states. Finally, patch-clamp recordings were performed to investigate the relationship between LPS, the BKCa channel and membrane currents in mouse myometrial smooth muscle cells (mMSMCs). We confirmed the expression of BKCa and TLR4 in the myometrium of GD18.5 mice and found that inhibiting BKCa channels with paxilline suppressed both spontaneous and LPS-stimulated uterine contractions. Furthermore, application of BKCa inhibitors (paxilline or iberiotoxin) after LPS inhibited BKCa channel activity in mMSMCs. Moreover, pretreatment with BKCa inhibitor or the TLR4 inhibitor suppressed LPS-activated BKCa currents. Our study demonstrates that BKCa channels are involved in both basal and LPS-stimulated uterine contraction in pregnant mice.

MicroRNA-1 Deficiency Is a Primary Etiological Factor Disrupting Cardiac Contractility and Electrophysiological Homeostasis.

MicroRNA-1 (miR1), encoded by the genes miR1-1 and miR1-2, is the most abundant microRNA in the heart and plays a critical role in heart development and physiology. Dysregulation of miR1 has been associated with various heart diseases, where a significant reduction (>75%) in miR1 expression has been observed in patient hearts with atrial fibrillation or acute myocardial infarction. However, it remains uncertain whether miR1-deficiency acts as a primary etiological factor of cardiac remodeling. miR1-1 or miR1-2 knockout mice were crossbred to produce 75%-miR1-knockdown (75%KD; miR1-1+/-:miR1-2-/- or miR1-1-/-:miR1-2+/-) mice. Cardiac pathology of 75%KD cardiomyocytes/hearts was investigated by ECG, patch clamping, optical mapping, transcriptomic, and proteomic assays. In adult 75%KD hearts, the overall miR1 expression was reduced to ≈25% of the normal wild-type level. These adult 75%KD hearts displayed decreased ejection fraction and fractional shortening, prolonged QRS and QT intervals, and high susceptibility to arrhythmias. Adult 75%KD cardiomyocytes exhibited prolonged action potentials with impaired repolarization and excitation-contraction coupling. Comparatively, 75%KD cardiomyocytes showcased reduced Na+ current and transient outward potassium current, coupled with elevated L-type Ca2+ current, as opposed to wild-type cells. RNA sequencing and proteomics assays indicated negative regulation of cardiac muscle contraction and ion channel activities, along with a positive enrichment of smooth muscle contraction genes in 75%KD cardiomyocytes/hearts. miR1 deficiency led to dysregulation of a wide gene network, with miR1's RNA interference-direct targets influencing many indirectly regulated genes. Furthermore, after 6 weeks of bi-weekly intravenous tail-vein injection of miR1 mimics, the ejection fraction and fractional shortening of 75%KD hearts showed significant improvement but remained susceptible to arrhythmias. miR1 deficiency acts as a primary etiological factor in inducing cardiac remodeling via disrupting heart regulatory homeostasis. Achieving stable and appropriate microRNA expression levels in the heart is critical for effective microRNA-based therapy in cardiovascular diseases.

A nonlinear contraction channel design inspired by typical mathematical curves: Boosting net power and water discharge of PEM fuel cells

The next-generation fuel cell needs to fit high current density operating conditions, necessitating improved flow fields with superior capabilities in mass transfer and drainage. This study introduces four innovative nonlinear contraction channels aimed at enhancing net power and mitigating waterflooding under high current density. This design draws inspiration from classical mathematical curves, which can provide targeted mass transfer enhancement contingent upon species distribution. Multiple quantitative indicators are employed to evaluate the efficacy of nonlinear structures in cross-scale mass transfer, drainage, temperature uniformity, and power consumption. Numerical results indicate that the exponential-like curve channel exhibits notably superior overall performance. Its nonlinear contraction region induces purge airflow at the tail of channel, facilitating drainage and boosting the local mass transfer flux in oxygen-starved region by 48.75%. The utilization of nonlinear contraction structures alters the diffusion-convection distribution mechanism and increases the convective mass transfer proportion. Under conditions of high current density, there is a noticeable rise in the Peclet number. Considering the pumping power loss, the hyperbolic tangent, quarter-ellipse, parabolic, and exponential-like curve flow channels can enhance the net power by 3.10%, 6.82%, 8.57%, and 10.04% over straight channels. Additionally, the exponential-like curve channel enhances temperature uniformity in the catalyst layer under rated working conditions, whereas the hyperbolic tangent flow channel demonstrates superior uniformity in higher current density.

Patterns and processes of channel and floodout adjustment in a discontinuous dryland river, semi-arid eastern Australia

Alluvial rivers in semi-arid and arid landscapes are prone to episodic geomorphic adjustments related to long-term sediment accumulation and occasional reworking by flash floods. However, few studies document the rates, patterns and processes leading to channel breakdown, particularly avulsion and floodout. These intrinsically driven adjustments may pose a risk to water resource availability through redistribution of water and sediment on the floodplain. To address this knowledge gap, channel change associated with avulsion and flooding in the last ∼30 years were quantified for Little Faulkenhagen Creek, a dryland river of the Murray-Darling Basin, Australia. The semi-arid, low gradient catchment promotes transmission losses, which with loss of valley confinement leads to channel adjustment and contraction to occur where water, sediment and energy are spread across the floodplain. Pronounced downstream changes occur in channel capacity (i.e., reductions in bankfull width, depth and area) and hydrology (i.e., reductions in bankfull discharge and stream power) as the river enters the floodout zone. Vegetation roughness increases in and around the floodout, where shrubs and river redgum trees line and encroach upon the channel. Mapping and analysis of hydro-geomorphological parameters using cross sections from 1991 to 2021 reveal recent changes in channel capacity, discharge and stream power. The upper reach has experienced substantial channel widening from erosion, while the lower reach leading into the floodout has contracted because of sediment deposition within the channel. Unchannelised floodwaters are deflected around a raised alluvial ridge and over the floodout eventually dropping into several migrating upstream knickpoints (head-cutting gullies) with retreat rates up to 32 m a−1. Therefore, both the existing channel slope (i.e., decline) and potential avulsion courses (i.e., increase) are affected by reduced energy and enhanced sedimentation. The net result of upstream in-channel sedimentation and aggradation on the floodout and downstream incision and gullying is that the floodout has migrated ∼1 km upstream and the river is at risk of a secondary avulsion as gullies retreat towards the main channel, potentially circumventing the floodout within ∼11 years. An erosion cell conceptual model is suitable for this system, where sediment from the local upstream production (erosion) zone is transferred downstream to a sink (deposition) zone. Erosion and deposition will fluctuate over the long-term, leading to periods with dominantly incisional or aggradational processes. Cycles of erosion and deposition will vary over time and external forces may influence a wholesale shift to a new fluvial state. Understanding the context and patterns of recent dryland river adjustments, as well as the dominant processes and their variability, can assist water and land management.

Effect of entry geometry on droplet dynamics in contraction microchannel

In droplet-based microfluidic systems, the movement and control of liquid droplets are primarily governed by microchannel geometry. The aim of this study is to examine droplet dynamics in contraction microchannels by using three-dimensional simulation and theoretical modeling. This work specifically describes three regimes of the droplet dynamics, including the trap, squeeze, and breakup regimes, and investigates the effects of capillary number (Ca), entry angle (α), and contraction channel ratio (C). Additionally, a theoretical model is proposed to describe the transition between squeeze and trap regimes, which depends on the entry angle. The critical value of capillary number (Ca1c) for this transition is observed to be Ca1c=a(CM−b/α), where a and b are fitted parameters. Meanwhile, the entry angle is found to have no influence on the transition from squeeze to breakup regime. The droplet deformations, retraction, and/or breakup position are quantitatively investigated for a wide range of capillary number and entry angle. The aforementioned findings would provide valuable recommendations for designing contraction micro channels.

Numerical Study on the Influence of Variable Section-Enhanced Mass Transfer Flow Field Design on PEMFC Performance Based on Underrib Convection Flow

The optimal design of variable section is a flow field optimization method that changes the pressure of the reacting gas in the flow channel by setting up a contraction surface in the flow channel, which is effective in improving many aspects of the proton exchange membrane fuel cell (PEMFC) performance. However, there are also problems such as uneven oxygen distribution in some of the flow channels, and the current density and net output power are not significantly improved. To find a balance among gas transfer efficiency, drainage capacity, uniformity of current density distribution, and output performance, this paper investigates the design of a variable cross-section-enhanced mass transfer flow field for PEMFC flow channel contraction by establishing a three-dimensional numerical model, starting from the sidewall width direction and the bottom height direction of the flow channel cross-section dimensions, in order to assess the effects of variable cross-section contraction at the bottom and sidewalls of the flow channel on the cell performance. The polarization curves, mass transfer capacity, current density distribution, and net output power of the variable cross-section contraction flow field are analyzed and compared with the straight flow field. On this basis, the optimum size parameters and operating parameter combinations are determined. Variable cross-sectional contraction flow field improves PEMFC output performance. The contraction of the variable cross-section contraction flow field at the sidewalls effectively improves reactive gas transfer efficiency and drainage capacity, improves current density distribution, and increases the net output power of the PEMFC. In particular, the sidewall contraction flow field has a 9.0% increase in power density, a 6.45% increase in the effective mass transfer coefficient (EMTC), a 6.52% increase in uniformity of current density distribution, and a 6.05% net power increment compared to the straight flow field, respectively. The best output performance, the highest oxygen concentration, and the lowest water concentration are achieved with a combination of parameters: number of sidewall contractions N = 6 , length L f = 6 mm , and width W f = 1.2 mm . And a wide range of air stoichiometry ratios are applied when the contraction of the variable cross-section contraction flow field is located at the sidewalls. Increasing the cathode stoichiometry ratio from 10 to 50 increased the cell power density by 25.5% and from 50 to 90 increased the cell power density by 9.5%. The simulation results can provide theoretical basis for the application of variable section flow field design for practical PEMFC.

Numerical study on the effect of tangential intake design and inflow discharge on vertical dropshaft assessment using pressure and velocity distributions

Tangential intake structures with vertical dropshafts are commonly employed in stormwater and urban drainage systems. Vortex and plunging flows are the two typical flow patterns observed in dropshafts, with the former being the desired due to its favourable drainage performance and enhanced safety. The transition between these flow patterns is primarily influenced by the structural design and rate of flow discharge. To investigate the interception performance and the transition criteria between vortex and plunging flows, a series of numerical simulations were conducted. The effects of the approach channel slope, contraction ratio, and flow discharge were analyzed by comparing the evolution of the water surface, pressure and velocity distributions, and swirling distance across various scenarios. With a higher flow rate of 20 L/s, obvious water congestion was observed in dropshafts with contraction ratios below 0.4 and horizontal approach channels. However, the inflow channel was not congested in cases with sloping approach channels, indicating higher drainage efficiency of intake structures with slopping channels. Two hydraulic factors, namely, the minimum to maximum wall pressure ratios (Pmin/Pmax) and the minimum Vr/Vz ratios (Vr/Vz)min, were employed to differentiate between vortex flow and nonrotational flow. These two factors consistently led to the same conclusions under both subcritical and supercritical inflow conditions, indicating their validity and their potential application in the design and optimization of intake structures. The criteria of Pmin/Pmax > 0.2 and (Vr/Vz)min > 0.2 can be used as criteria for the formation of stable vortex flow.

Analysis of heroin effects on calcium channels in rat cardiomyocytes based on transcriptomics and metabolomics.

Heroin can cause damage to many human organs, possibly leading to different types of arrhythmias and abnormal electrophysiological function of the heart muscle and the steady state of calcium-ion channels. We explored cardiomyocytes treated with heroin and the effect on calcium-ion channels. Transcriptomics and metabolomics were used to screen for differential genes and metabolite alterations after heroin administration to jointly analyze the effect of heroin on calcium channels in cardiomyocytes. Cardiomyocytes from primary neonatal rats were cultured in vitro and were treated with different concentrations of heroin to observe the changes in morphology and spontaneous beat frequency and rhythm by a patch clamp technique. Transcriptomic studies selected a total of 1,432 differentially expressed genes, 941 upregulated and 491 downregulated genes in rat cardiomyocytes from the control and drug intervention groups. Gene Ontology functional enrichment showed that 1,432 differential genes selected by the two groups were mainly involved in the regulation of the multicellular organismal process, response to external stimulus, myofibril, inflammatory response, muscle system process, cardiac muscle contraction, etc. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that these genes were mainly concentrated in cardiac muscle contraction, osteoclast differentiation, adrenergic signaling in cardiomyocytes, dilated cardiomyopathy, hypertrophic cardiomyopathy, and other important pathways. Metabolomic testing further suggested that cardiomyocyte metabolism was severely affected after heroin intervention. After the treatment with heroin, the L-type calcium channel current I-V curve was up-shifted, the peak value was significantly lower than that of the control group, action potential duration 90 was significantly increased in the action potential, resting potential negative value was lowered, and action potential amplitude was significantly decreased in cardiomyocytes. In this study, heroin could cause morphological changes in primary cardiomyocytes of neonatal rats and electrophysiological function. Heroin can cause myocardial contraction and calcium channel abnormalities, damage the myocardium, and change the action potential and L-type calcium channel.

Numerical Simulation of Contraction Flows of Newtonian Fluid Using Taylor Galerkin Pressure Correction Finite Element Method

In this study, numerical simulation of Newtonian fluids in contraction channels is performed based on the Taylor Galerkin-pressure correction finite element method (TGPC-FEM). Here, three different contraction channel geometries (4:1, 6:1, and 8:1) were simulated in this investigation. Usually, the continuity equation and momentum equation are governed this type of fluid. These equations are presented in our study in cylindrical coordinate system. This research examined the impact of varying Reynolds number and geometry area difference on the rate of convergence for solution components, as well as the influence of geometry area difference on level of velocity and pressure.

Characteristics of Viscoplastic Fluid Flow at Various Heat Transfer Regimes on the Walls of a Sudden Contraction Channel

Characteristics of Viscoplastic Fluid Flow at Various Heat Transfer Regimes on the Walls of a Sudden Contraction Channel

Lem2 is essential for cardiac development by maintaining nuclear integrity.

Nuclear envelope integrity is essential for the compartmentalization of the nucleus and cytoplasm. Importantly, mutations in genes encoding nuclear envelope (NE) and associated proteins are the second highest cause of familial dilated cardiomyopathy. One such NE protein that causes cardiomyopathy in humans and affects mouse heart development is Lem2. However, its role in the heart remains poorly understood. We generated mice in which Lem2 was specifically ablated either in embryonic cardiomyocytes (Lem2 cKO) or in adult cardiomyocytes (Lem2 iCKO) and carried out detailed physiological, tissue, and cellular analyses. High-resolution episcopic microscopy was used for three-dimensional reconstructions and detailed morphological analyses. RNA-sequencing and immunofluorescence identified altered pathways and cellular phenotypes, and cardiomyocytes were isolated to interrogate nuclear integrity in more detail. In addition, echocardiography provided a physiological assessment of Lem2 iCKO adult mice. We found that Lem2 was essential for cardiac development, and hearts from Lem2 cKO mice were morphologically and transcriptionally underdeveloped. Lem2 cKO hearts displayed high levels of DNA damage, nuclear rupture, and apoptosis. Crucially, we found that these defects were driven by muscle contraction as they were ameliorated by inhibiting myosin contraction and L-type calcium channels. Conversely, reducing Lem2 levels to ∼45% in adult cardiomyocytes did not lead to overt cardiac dysfunction up to 18 months of age. Our data suggest that Lem2 is critical for integrity at the nascent NE in foetal hearts, and protects the nucleus from the mechanical forces of muscle contraction. In contrast, the adult heart is not detectably affected by partial Lem2 depletion, perhaps owing to a more established NE and increased adaptation to mechanical stress. Taken together, these data provide insights into mechanisms underlying cardiomyopathy in patients with mutations in Lem2 and cardio-laminopathies in general.

Numerical Simulation on Heat Transfer Augmentation by Using Innovative Hybrid Ribs in a Forward-Facing Contracting Channel

This study aims to investigate the thermal behavior and aerodynamic phenomena in a heated channel with varied rib configurations using computational fluid dynamics (CFD) simulations. Incorporating ribs in such systems enhances heat transfer and increases flow resistance and manufacturing costs. Understanding heat exchanger theory, measurement methods, and numerical calculations are crucial for creating efficient heat exchangers. The current research employs numerical analysis to assess the impact of hybrid ribs on heat transfer enhancement in forward-facing contracting channels (FFS). A two-dimensional forced convection heat transfer simulation under turbulent flow conditions was performed, considering the presence and absence of ribs with dimensions of 1 cm by 1 cm and spaced 11 cm apart. The arrangement of the ribs causes symmetrical temperature and flow distribution after and before each rib. The results demonstrate that the use of hybrid ribs outperforms the use of individual rib configurations in terms of thermal performance. This is due to the distinct flow patterns generated as the fluid passes through each rib. The triangle ribs had a more significant impact on the pressure drop than other rib configurations, while the cross ribs showed a lesser effect. The ribs improve the heat transfer coefficient while increasing the pressure drop, and the values of the Reynolds number were found to be directly proportional to the heat transfer coefficient and the pressure drop. The study concludes with a qualitative and quantitative analysis demonstrating the accuracy and coherence of the obtained computational results.

Couple stress ternary hybrid nanofluid flow in a contraction channel by means of drug delivery function

The rheological perception of blood circulation with the dispersion of metal or non-metal nanomaterials via a squeezing channel is gaining more attention because of implementations in the blood filtration system, nano-pharmacology, obstructed hemodynamics, nano-hemodynamics, care of hemodynamic diseases, and some other areas. Inspired by the innovative importance and study in such a domain a computational hemodynamically framework is developed to simulate the hemodynamic properties of blood steam under the composition of nanomaterials through a squeezing channel. CuO, TiO2, and Al2O3 nanoparticles are dissolved in the blood to generate a tri-hybrid nano-blood emulsion (CuO+TiO2+Al2O3/blood). The blood flow is commonly described using the couple stress, fluid model. The concept of nonlinear radiation is also utilized in the equation of heat for the viability of drug delivery. The effects of MHD and the heat source are also considered. According to the existing research, the interaction of TiO2 nanoparticles with any other metal nanoparticle can kill more cancer cells than TiO2 alone. The mathematical framework of a squeezing channel is formulated for motion and energy and then solved the model problem by using the HAM technique. The numerical outputs were presented in the form of graphs for a random interval of model factors included for thermal and velocity distributions additionally to this, Cf and Nu are also deliberated through charts. Furthermore, the percentage-wise enhancement in Nul and Nuu is also displayed. The thermal profile improves as the values of M,ϕ,Rd and λ>0 grow, but it declines as λ<0 increases. The conclusions of the current model could be pertinent to regulating blood circulation and drug delivery systems.