Modeling shear‐induced flow dynamics in a thermal Riga channel containing radioactive rGO‐magnetite‐mercury in an intense electromagnetic rotational setting

Applying external magnetic or electric fields, especially via a Riga plate, significantly improves flow efficiency by reducing friction and turbulence, enabling better flow management. This enhancement is particularly advantageous in enhancing the performance of engineered systems and turbomachinery. Consequently, our research delves into the dynamics of a low‐ionization fluid in an extended infinite porous Riga channel within a rotating setup influenced by Hall and ion‐slip electromotive forces. The model examines various pressure gradient scenarios: impulsive pressure gradient (IPG), cosine pressure gradient (CPG), and sine pressure gradient (SPG). We represent this flow model through time‐varying partial differential equations and solve these using the Laplace transform (LT) method to obtain exact analytical solutions. Our research carefully delineates the dominance of key factors on the flow traits, employing graphical representations for IPG, CPG, and SPG scenarios. Our key observations reveal an amelioration in the modified Hartmann number notedly enhances the velocity components for all pressure gradient types. A higher rotation parameter tends to reduce the primary velocity's shape profile, while the secondary velocity exhibits the opposite trend. The primary velocity notably boosts with a rise in the Hall parameter, whereas the secondary velocity decreases. Both primary and secondary velocities are generally higher in the IPG scenario than in CPG and SPG. Additionally, a greater modified Hartmann number intensifies shear stresses in all pressure gradient cases, with the shear stresses at the lower plate being lower in IPG than in CPG and SPG. These findings offer substantial contributions to various sectors, including nuclear reactor technology, spacecraft propulsion, satellite operations, space exploration, aerospace engineering, and so forth.

Dynamics pattern of a radioactive rGO-magnetite-water flowed by a vibrated Riga plate sensor with ramped temperature and concentration

<abstract> <p>This investigation presents the fuzzy nanoparticle volume fraction on heat transfer of second-grade hybrid $ {\text{A}}{{\text{l}}_{\text{2}}}{{\text{O}}_{\text{3}}}{\text{ + Cu/EO}} $ nanofluid over a stretching/shrinking Riga wedge under the contribution of heat source, stagnation point, and nonlinear thermal radiation. Also, this inquiry includes flow simulations using modified Hartmann number, boundary wall slip and heat convective boundary condition. Engine oil is used as the host fluid and two distinct nanomaterials ($ {\text{Cu}} $ and $ {\text{A}}{{\text{l}}_{\text{2}}}{{\text{O}}_{\text{3}}} $) are used as nanoparticles. The associated nonlinear governing PDEs are intended to be reduced into ODEs using suitable transformations. After that 'bvp4c, ' a MATLAB technique is used to compute the solution of said problem. For validation, the current findings are consistent with those previously published. The temperature of the hybrid nanofluid rises significantly more quickly than the temperature of the second-grade fluid, for larger values of the wedge angle parameter, the volume percentage of nanomaterials. For improvements to the wedge angle and Hartmann parameter, the skin friction factor improves. Also, for the comparison of nanofluids and hybrid nanofluids through membership function (MF), the nanoparticle volume fraction is taken as a triangular fuzzy number (TFN) in this work. Membership function and $ \sigma {\text{ - cut}} $ are controlled TFN which ranges from 0 to 1. According to the fuzzy analysis, the hybrid nanofluid gives a more heat transfer rate as compared to nanofluids. Heat transfer and boundary layer flow at wedges have recently received a lot of attention due to several metallurgical and engineering physical applications such as continuous casting, metal extrusion, wire drawing, plastic, hot rolling, crystal growing, fibreglass and paper manufacturing.</p> </abstract>

In a recent study, researchers investigated the flow behavior of Casson Hybrid nanofluids (HNFs) combination of single and multi-walled carbon nanotubes (SWCNTs), (MWCNTs) on a Riga plate for drug delivery applications. The study found that the Casson HNFs exhibited non-Newtonian behavior on the Riga plate, with the presence of nanoparticles causing an increase in viscosity and shear-thinning behavior. This rheological behavior is favorable for drug delivery applications as it improves the stability and dispersion of drug particles in the fluid. The similarity equations of the flow problem are easily tackled with the homotopy analysis method (HAM) built on fundamental homotopy mapping. In high-speed flows, Riga actuators are expected to achieve the requirements, since HNF is enhanced by modified Hartmann numbers. As the Eckert number, heat generation/absorption parameter, and thermal relaxation time parameter decrease the temperature, thermal transport increases. Furthermore, with the increments in paramount parameters, the skin friction coefficient and heat transfer rate are remarkably meliorated under higher modified Hartmann number. Furthermore, the study also found that the Casson Hybrid nanofluids showed enhanced heat transfer properties on the Riga plate, which is beneficial for localized drug delivery applications that require precise temperature control.

The core determination of this article is to investigate the augmentation in the radiative heat transfer rate of Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> -MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O hybrid nanofluid specifying a flow over an inclined plate subject to ramped heating and heat generation/consumption effects. The flow of considered hybrid nanofluid is developed due to the ramped motion of the inclined plate that encounters the magnetic effects and immersed in a porous material. The fractional form of energy and momentum equations is obtained by employing the concept of the Atangana-Baleanu fractional derivative. Some unit-free quantities are introduced and the Laplace transform method is operated to construct the exact solutions of these equations. The noteworthy physical significance of involved parameters is discussed with the aid of graphical illustrations. To analyze the behavior of shear stress and heat transfer rate, numerical computations are tabulated in terms of skin friction coefficient and Nusselt number. All the figures and tables are prepared for both ramped and isothermal boundary conditions to highlight the impacts of the ramped heating condition and ramped motion of the inclined plate. It is observed that a water-based hybrid nanofluid that contains equal proportions of Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> and MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanoparticles exhibits an improvement of 6.14% in the heat transfer rate. The motion of hybrid nanofluid is retarded by fractional and inclination parameters, whereas the thermal radiation parameter serves as a flow supportive factor. Moreover, it is realized that ramping of the boundary surface and the fractional model are more effective for enhancing the heat transfer rate and limiting the shear stress. This result accentuates the significance of ramping technique in achieving a faster cooling rate and better flow control for various engineering applications.

This study investigates the flow and heat transfer of mono and hybrid nanofluids owing to a stretching cylinder in a porous medium under the influence of a magnetic field and convective boundary condition. The hybrid nanofluid is made up of copper (Cu) and silver (Ag) nanoparticles dispersed in a water-ethylene glycol mixture at a mass ratio of 50:50. The binary mixture of water and ethylene glycol is intermixed with spherical-shaped nanoparticles (copper) to create a mono nanofluid. The study considers the effects of generalized Fourier’s law and heat generation/absorption. The novelty of the study lies in considering the comparison of hybrid and mono nanofluid flows heat transfer efficiency with assumed effects and convective condition at the boundary of the cylinder. A system of ordinary differential equations (ODEs) controlling the flow and heat transport are derived using similarity transformations and are solved numerically using the bvp4c program of MATLAB software. The work explores the ways in which different parameters, such as the shape of the nanoparticles and their volume percentage, affect the pertinent profiles and are depicted in the form of graphical illustrations and numerically tabulated values. The results demonstrate that, in comparison to mono nanofluids, hybrid nanofluids including spherical and blade nanoparticles have a higher heat transfer rate and reduced surface drag when the particle volume fraction is increased in a water-ethylene glycol combination. Furthermore, there is a 0.83% increase in the heat transfer rate for hybrid nanofluids in comparison to mono nanofluids. This is because compared to mono nanofluids, hybrid nanofluids have lower viscosity and better heat conductivity. The results obtained in this study are vetted by making a comparison with published works and an excellent agreement between the values is seen. The study may find use in solar thermal systems, electronic cooling, heat exchangers, and other areas.

This investigation intends to explore the peristaltic transport of rotating fluid in a channel. The channel is considered symmetric with flexible walls, and porous medium fills the saturated space. In this analysis, hybrid nanofluid consisting of titanium oxides and copper particles is taken. Water is used as the base fluid. MHD and Hall effects are employed in this problem. Formulation of energy equation is based on radiation and non-uniform heat source or sink parameter. Convection conditions are utilized for the boundary. Thermodynamics second relation is employed for entropy generation. Maxwell–Garnetts model of thermal conductivity is employed. Numerical analysis is carried out using NDSolve of Mathematica. The effect of nanoparticle volume fraction, Taylor number, Hartman number, porosity and Hall parameters is analyzed for axial and secondary velocities, temperature, entropy generation and heat transfer rate. This study divulges that an enhancement in rotation parameter caused an increase in secondary velocity. Moreover, as volume fraction of nanoparticles enhances from 0.01 to 0.04, decay is noticed in fluid’s axial and secondary velocities. In this case, entropy also decreases. This study further disclosed that heat transfer rate gradually increases as we exceed the volume fraction of nanoparticles from 0.02 to 0.08. More pores also lead to an enhancement in fluid velocity, temperature and entropy.

Wall shear stress (SS) plays an important role in the initiation and proliferation of coronary atherosclerosis, especially for bifurcations. Stenting in the coronary artery will cause many different changes in velocity, flow, cross-sectional area, and especially the wall SS. However, it is still unknown how much wall SS distribution varies with stenting in coronary bifurcation. The purpose of this study was to investigate the magnitude and distribution of wall SS after the classical crush stenting for bifurcation lesions. Eleven patients with true coronary bifurcation stenting by the classical crush technique were included. We studied the difference of wall SS between restenosis and nonrestenosis groups in these patients. The differences in SS between preprocedure and postprocedure, as well as between immediately postprocedure and after an 8-month follow-up, were also analyzed. Diameter stenosis or minimal lumen diameter were measured by quantitative coronary analysis. The commercial CD STAR-CCM+ was used to calculate the SS. At baseline, the SS in all the segments of all patients was high. The baseline SS of the restenosis group was 50% lower than the nonrestenosis group. Immediately after percutaneous coronary intervention (PCI), the SS in both areas decreased; however, the SS of the nonrestenosis group decreased to its lowest level possible while the SS of the restenosis group decreased moderately. Eight months later, the SS of all the segments of the nonrestenosis group remained persistently low at the same level of right after PCI. In contrary, the SS in the restenosis group returned to near its baseline level. From our study, after a 2-stent crush technique using drug-eluting stents (DES), the degree of SS reduction appears to predict in-stent restenosis (ISR). A SS decrease to its lowest level and remaining homogenously low is a prime condition to prevent ISR. A baseline low SS, which decreases minimally after PCI and recovers to around its baseline level, appears to be the setting for restenosis. These conditions can be evaluated as predictors of lesions that may need surveillance angiography and proper IVUS evaluation to prevent future in-stent restenosis.

This study is about thermal enhancement in hybrid nano-ferrofluid. The conservation equations with thermo-correlations are solved numerically and computed solutions are used for parametric study related to flow of fluid and transfer of heat energy. The convergent solutions are derived via the finite element method (FEM). A mesh-free study is performed. Flow experiences a sufficient amount of resistive force by the porous medium. It is noted that Darcy porous is less resistive than Forchheirmer porous medium. It is also noted that convective heat transfer is compromised when the Forchheirmer parameter is increased. Dissipation effects are responsible for an increase in temperature and hence, an increase in thermal boundary layer thickness is noted. It is also observed that heat dissipation in a hybrid nanofluid is stronger than that in a nanofluid. The numerical values read the wall shear stress exerted by hybrid nanofluid is greater than wall shear stress by nano-ferrofluid. The wall shear stress increases as a function of the ferro-hydrodynamic parameter. However, the wall heat transfer rate (Nusselt number) decreases as the ferro-hydrodynamic parameter is increased. Similarly, wall shear stress increases versus Curie temperature number whereas Nusselt number decreases when the porosity parameter is increased. The porous medium is responsible for more wall shear stress on the surface. The transfer of heat in the presence of a porous medium in a fluid is greater than the rate of heat transfer in fluid in the absence of a porous medium. Viscous dissipation is responsible for the increase of the rate of heat transfer.

The overwhelming applications of hydromagnetic flows of hybrid nanofluid and second-grade nanofluid in advanced nanotechnology and biomedical fields motivated this research work. This paper explores the heat transfer in unsteady hydromagnetic flows of Titanium Oxide-Copper Oxide-Engine Oil (TiO2-CuO-EO) second-grade hybrid nanofluid in a uniform porous matrix bounded by two symmetrically placed vertical walls. The magnetic field applied strength is considered strong enough to generate Hall and ion-slip currents and is considered moving. The governing equations are obtained from the fundamental physical laws involved in the physical problem. An analytical approach is opted for solving the governing equations. The MATLAB computation of the solutions highlights the impressions of flow impacting parameters to the velocity, temperature, shear stress and rate of heat transport. Two special cases of interest are considered for the results analysis, namely, (a) the moving magnetic field, and (b) the stationary magnetic field. The study results infer that the static magnetic field employs the flow-suppressing force while the moving magnetic field employs the flow-boosting force in the flow field. In a static magnetic field, the velocity in the hybrid nanofluid is higher than the nanofluids. This behaviour is reversed in the moving magnetic field. The hybrid nanofluids are thermally more efficient than the nanofluids. In this study, it is noted that the rate of heat transfer at the left moving wall in the hybrid nanofluid is smaller than the nanofluid while at the right static wall, this effect is the opposite. This may be due to the fluctuation of wall temperature of the left-moving wall.

Heat transfer analysis of radiator using different shaped nanoparticles water-based ternary hybrid nanofluid with applications: A fractional model

The fluid containing solid nanoparticles “nanofluid” performed more effectively compared to conventional fluids. The thermal scientists and scholars considered nanofluid in their research due to its useful applications in different thermal systems. But nanofluid still not enough for the required thermal transport properties. Therefore, the researchers tried to disperse two or more than two nanoparticles which are called hybrid and tri‐hybrid nanofluid. It was tested experimentally that these hybrid nanofluids are more efficient fluids in different cooling systems compared to nanofluid and regular fluids. The present article carried out the research about the suspension of three different kinds of nanoparticles in various shapes for advance cooling applications in industries and engineering problems. The three nanoparticles are cylindrical carbon nanotubes, spherical aluminum oxide, and platelet shaped(Graphene) are mixed in water flowing in a rotating disk. This advance fluid has remarkable enhancement in the heat transfer rate in comparison with regular fluid, mono nanofluid and hybrid nanofluid. In this study viscoelastic radiative ternary hybrid nanofluid is considered on a rotating disk. The solutions are obtained by using the HAM method. For physical interpretation, all the flow parameters are discussed through graphs. The impact of volume fraction on the flow and heat transfer is also evaluated and presented in graphs. From the comparison, it was declared that tri‐hybrid nanofluid has the best thermal performance compared to hybrid and mono nanofluid. Furthermore, radiation increases the temperature of the fluid, while viscoelastic parameter decreases the radial and tangential velocity. From the present study, we noticed that by considering the tri‐hybrid mixture in water, the rate of heat transfer can be enhanced up to 33.69%. Finally, the results obtained show that the tri‐hybrid nanofluid has excellent performance in the heat transfer rate.

Hybrid nanofluids are significant in biomedical, industrial, transportation, as well as several engineering applications due to their high thermal conductivity and mass transfer enhancement nature in contrast to regular fluids and nanofluids. Taking this into consideration, the present problem explores the flow of hybrid nanofluid (Ag − TiO 2/H 2 O) over a stretching cylinder subject to Newtonian heat and mass conditions. The novel aspect of the current work is to analyze the heat and mass transfer characteristics of MHD hybrid nanofluid flow on Darcy-Forchheimer porous medium in addition to activation energy, nonlinear thermal radiation, heat generation/absorption, viscous and Joulian dissipation. Further, Silver (Ag) and Titanium oxide (TiO 2) are the constituent nanoparticles of the water-based hybrid nanofluid owing to their stable chemical features and extensive industrial manufacturing. By introducing suitable similarity transformations, the governing partial differential equations (PDEs) of the developed model are reduced to ordinary differential equations (ODEs), and then the numerical solution is procured with shooting technique by using MATLAB solver bvp4c. The influence of the pertinent parameters is depicted graphically and described elaborately. The analysis indicates that velocity exhibits a declining trend against the permeability and Forchheimer parameters, while the temperature profiles show opposite behavior. The radiation and conjugate heat parameters (R, γ 1) upgrade the heat transfer rate, while the curvature and conjugate mass parameters (α c , γ 2) amplify the mass transfer rate. The maximum heat transfer rate of Ag − TiO 2/H 2 O hybrid nanofluid is 2.3344 attained for γ 1 = 0.6. The investigation demonstrates larger heat and mass transfer rates for Ag − TiO 2/H 2 O hybrid nanofluid than Ag − H 2 O nanofluid. The outcomes of the present investigation have practical applications in conjugate heat transfer over fins, development of vaccines, effluent treatment plants, solar cells, heat exchangers, and many more. An excellent agreement is achieved on comparing our numerical results with the published results in the literature.

The present study addresses the fluid transport behaviour of the flow of gold ( Au )‐copper ( Cu )/biomagnetic blood hybrid nanofluid in an inclined irregular stenosis artery as a consequence of varying viscosity and Lorentz force. The nonlinear flow equations are transformed into dimensionless form by using nonsimilar variables. The finite‐difference technique (FTCS) is involved in computing the nonlinear transport dimensionless equations. The significant parameters like angle parameter, the Hartmann number, changing viscosity, constant heat source, the Reynolds number, and nanoparticle volume fraction on the flow field are exhibited through figures. Present results disclose that the Lorentz force strongly lessens the hybrid nanofluid velocity. Elevating the Grashof number values enhances the rate of blood flow. Growing values of the angle parameter cause to reduce the resistance impedance on the wall. Hybrid nanoparticles have a superior wall shear stress than copper nanoparticles. The heat transfer rate is amplifying at the axial direction with the growing values of nanoparticles concentration. The applied Lorentz force significantly reduces the hybrid and unitary nanofluid flow rate in the axial direction. The hybrid nanoparticles expose a supreme rate of heat transfer than the copper nanoparticles in a blood base fluid. Compared to hybrid and copper nanofluid, the blood base fluid has a lower temperature.

Radiative MHD flow of Casson hybrid nanofluid over an infinite exponentially accelerated vertical porous surface