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The purpose of this paper is to investigate the enhancement of the performance of bubble absorber using hybrid nanofluid as a cooled NH₃/H₂O absorption system to reduce their size and to find the best fitting model. A numerical model for ammonia-water bubble absorber was developed to show the influence of operating conditions and design parameters on the absorber performance.

A finite difference numerical method is used to solve the numerical model. The model is subjected to the inlet conditions of liquid, vapor and coolant flow regimes. The absorber modeling was divided into small elements along the absorber length.

The model proposed is validated with previously published works. Then agreement between the both is considered as good.

Numerical results/The use of hybrid nanofluids.

The results showed that the hybrid nanofluid is the best cooling medium. Very high heat transfer rates are obtained because of the high thermal conductivity and specific heat of hybrid nanofluid, and consequently, the absorber size decreases. It was also found that the absorber thermal load and the mass absorption flux increase with increasing of solid volume fraction. Also, the existence of an optimal absorber length was revealed, required for complete absorption when using hybrid nanofluid as a cooling medium. It is recommended that using hybrid nanofluid to remove the heat from the absorber is the best candidate for NH₃/H₂O absorption performance enhancement.

Develops a fine element method employing Galerkin’s approach for the analysis of a vertical tubular bubble absorber working with R22‐DMF as working fluid. Aims to provide an understanding of the absorption process which helps in the design of bubble absorbers. Numerical experiments have also been carried out with ammonia‐water combination for the sake of comparison with the results in the literature and the agreement is found to be good. Suggests a correlation for mass transfer coefficient for vertical tubular bubble absorbers working with R22‐DMF. The use of the correlation can either be in estimating the mass transfer rates, or in fixing up the major design parameters such as diameter and length required for complete absorption.

The purpose of this paper is to examine numerically the magnetohydrodynamic (MHD) free convection and thermal radiation heat transfer of single walled carbon nanotubes-water nanofluid within T-inverted shaped corrugated cavity comprising porous media including uniform heat source/sink for solar energy power plants applications.

The two-dimensional numerical simulation is performed by drawing on Comsol Multiphysics program, based on the finite element process.

The important results obtained show that increasing numbers of Rayleigh and Darcy and the parameter of radiation enhance the flow of convection heat. Furthermore, by increasing the corrugation height, the convection flow increases, but it decreases with the multiplication of the corrugation height. The use of a flat cavity provides better output than a corrugated cavity.

The role of surface corrugation parameters on the efficiency of free convection and heat transfer of thermal radiation within the porous media containing the T-inverted corrugated cavity including uniform heat source/sink under the impact of Lorentz forces has never been explored. A contrast is also established between a flat cavity and a corrugated one.

The shock absorber is an important component of vehicle suspension that attenuates the vehicle vibration. Its running state directly affects the performance of the vehicle suspension. The purpose of this paper is to quantitatively study the relationship between damping characteristics and air chamber and oil properties in single-tube pneumatic shock absorber.

Combined with the principle of fluid dynamics and hydraulic transmission technology, the rebound stroke and compression stroke mathematical models, and damping characteristics simulation model are established to investigate the effect of the air chamber and oil property on damping characteristics.

Research results show that the initial pressure of the air chamber is the key parameter which influences the damping characteristics of the shock absorber. The change of the initial pressure has more impact on damping force, and less impact on the speed characteristic; the initial volume of the air chamber almost has no effect on the damping characteristics. The density and viscosity of the oil have certain influence on the damping characteristics. Therefore, selecting suitable damping oil is very important.

Using Matlab/Simulink software to build simulation models, its results are very accurate. The conclusions can provide a theoretical reference for the structure design of a single-tube pneumatic shock absorber.

The purpose of this paper is to study the natural convection and radiation heat transfer inside Nonagon inclined cavity with variable heated source length, which contains a porous medium saturated with nanofluid in the presence of uniform heat generation or absorption under the effect of uniform magnetic field with variable direction. The shape factor of nano particles is taking account for the model of nanofluid.

This study is established in two-dimensional space. The 2D numerical study is effectuated with Comsol Multiphysics based on the on the finite element method. The 2D equation system is exposed on dimensionless form taking into account the boundary conditions.

Results obtained show that the convection heat transfer is ameliorated with the augmentation of heated source length. The convection heat transfer is enhanced by increasing Rayleigh, Darcy numbers and the heated source length; however, it is reduced by rising Hartmann number. The presence of radiation parameter lead to improve the convection heat transfer in the presence of both uniform heat generation/absorption. The average Nusselt number reaches a maximum for an inclination of cavity γ = 45° and a minimum for γ = 60°. Both the increase of the shape factor of nano particles and the solid fraction of nano particles improve the convection heat transfer.

Different studies have been realized to study the heat transfer inside cavity contains porous medium saturated with nanofluid under magnetic field effect. In this work, the Nonagon geometric of cavity studied has never been studied. In addition, the effect of radiation parameter with relation of the shape factor of nanoparticles in the presence of uniform heat generation/absorption on the heat transfer performance have never been investigated. Also, the effect of magnetic field direction with relation of the inclination cavity on heat transfer performance.

This paper aims to study numerically the flow, heat transfer, and entropy generation of aqueous copper oxide-silver hybrid nanofluid over a down-pointing rotating vertical cone, with linear surface temperature (LST) and linear surface heat flux (LSHF), in the presence of a cross-magnetic field. In industrial applications, such as oil and gas plants, food industries, steel factories and nuclear packages, the real bodies may contain nonorthogonal walls and variable cross-section three-dimensional forms which this issue can clarify the importance of selective geometry in the present research.

The mass-based scheme is accomplished for the simulation, and the entropy generation and Bejan number will be analyzed in conjunction with the aforementioned model. It has been hypothesized that two types of boundary conditions (LST and LSHF) as well as five nanoparticle shapes (sphere, brick, cylinder, platelet and disk) present a collection of crucial results. The overseeing PDEs are changed over completely to the dimensionless ODEs, and these are solved by Runge–Kutta–Fehlberg approach combined with a shooting methodology for certain values of physical parameters.

Subsequent to the fantastic compromise of the computational outcomes with past reports, the outcomes are introduced to conduct the investigation of the hydrodynamics/thermal boundary layers, the skin friction and the Nusselt number, as well as entropy generation and Bejan number. A state of hybrid nanofluid, which exhibits a remarkable increase in heat transfer in comparison to the states of mono-nanofluid and regular fluid, has been found to have the highest Nusselt number; however, the skin friction values should always be taken into account and managed. The entropy generation improves with the mass of the second nanoparticle (silver), while the opposite pattern is exhibited for the Bejan number. Furthermore, the lowest value of entropy generation number belongs to the cylindrical shape of nanoparticles in the LST case. In final, a significant accomplishment of the current study is the accurate output of the mass-based scheme for an entropy analysis problem.

To the best of the authors’ knowledge, for the first time, in this study, a new development of natural convective flow of a hybrid nanofluid about the warmed (LST and LSHF) and down-pointing rotating vertical cone by the mass-based algorithm has been presented. The applied methodology considers the masses of base fluid (water) and nanoparticles (Ag and CuO) as an alternative to the first and second nanoparticles volume fraction. Indeed, the combination use of the Tiwari–Das nanofluid model and the mass-based hybridity algorithm for the entropy generation analysis can be the main novelty of this work.

The purpose of this paper is to study and analyze the converging/diverging channel flow and heat transfer with the multiple slips effect, which is a development of the Jeffery–Hamel problem using the mass-based hybrid nanofluid algorithm. Whereas transferring biological liquid by arteries is a vital issue, mathematical modeling of hybrid nanofluid flow containing titanium dioxide and silver as nanoparticles and blood as base liquid through a converging/diverging duct, which can be a useful analysis for the fields of drug delivery, has been investigated.

The present approach is based on the Tiwari–Das nanofluid method. In this modeling, the volume fraction of nanoparticles is replaced with nanoparticles masses. The partial differential equations of the mass, momentum and energy conservations are changed to the system of ordinary differential equations through the similarity solution method. The final governing equations are solved by Runge–Kutta–Fehlberg procedure and shooting method.

The effect of emerging parameters on the temperature, the velocity, the Nusselt number and the skin friction have been analyzed by graphical and tabular reports. It is observed that the opposition to hybrid nanofluid flow in the attendance of particles of nonspherical shapes is more enhanced than those in the attendance of particles of spherical shapes. This issue demonstrates that the rheology of a hybrid nanofluid is dependent on the shape of particles. Besides, backflow regimes form in the divergent channel for high values of Reynolds number, m₂ and a. Indeed, this modeling for the hybrid nanofluid can be useful in different technologies and industries such as biological ones. It is worth mentioning that the excellent achievement of the mass-based algorithm for heat transfer and hybrid nanofluid flow is the most important success of this study.

The main originality is related to the development of the Jeffery–Hamel problem using the mass-based hybrid nanofluid algorithm. This new mass-based method is a single-phase hybrid nanofluid approach that the inputs are masses of nanoparticles and base liquid. Besides, considering the multiple slips effect and also pure blood as base fluid in this problem are also new.

The purpose of this study is to model and solve numerically the three-dimensional off-centered stagnation point flow and heat transfer of magnesium oxide–silver/water hybrid nanofluid impinging to a spinning disk.

The applied effective thermophysical properties of hybrid nanofluid including thermal conductivity and dynamics viscosity are according to the reported experimental relations that would be expanded by a mass-based algorithm. The single phase formulations coupled with experimental-based hybrid nanofluid model is implemented to derive the governing partial differential equations which are then transferred to a set of dimensionless ordinary differential equations (ODEs) with the use of the similarity transformation method. Afterward, the reduced ODEs are solved numerically by bvp4c function from MATLAB that is a trustworthy and efficient code according to three-stage Lobatto IIIa formula.

The effect of spinning parameter and nanoparticles masses (m_MgO, m_Ag) on the hydrodynamics and thermal boundary layers behavior and also the quantities of engineering interest are presented in tabular and graphical forms. The recent work demonstrates that the analysis of flow and heat transfer becomes more complicated when there is a non-alignment between the impinging flow and the disk axes. From computational results demonstrate that, the radial and azimuthal velocities are, respectively, the increasing and decreasing functions of the disk spinning parameter. Further, for the greater values of the spinning parameter, an overshoot of the radial velocity owing to the centrifugal forces of the spinning disk is observed. Besides, the quantities of engineering interest gently enhance with first and second nanoparticle masses, while comparing their absolute values illustrates the fact that the effect of second nanoparticle mass (m_Ag) is greater. Further, it is inferred that the second nanoparticle’s mass enhancement results in the amplification of the heat transfer; although, the high skin friction and the relevant shear stress should be controlled.

The combination of experimental thermophysical properties with theoretical modeling of the problem can be the novelty of the present work. It is evident that the experimental relations of effective thermophysical properties can be trustable and flexible in the theoretical/mathematical modeling of hybrid nanofluids flows. Besides, to the best of the authors’ knowledge, no one has ever attempted to study the present problem through a mass-based model for hybrid nanofluid.

A study on heat and mass transfer behavior for an anisotropic porous medium embedded in square cavity/annulus is conducted using incompressible smoothed particle hydrodynamics (ISPH) method. In the case of square cavity, the left wall has hot temperature T_h and mass C_h and the right wall have cool temperature T_c and mass C_c and both of the top and bottom walls are adiabatic. While in the case of square annulus, the inner surface wall is considered to have a cool temperature T_c and mass C_c while the outer surface is exposed to a hot temperature T_h and mass C_h. The paper aims to discuss these issues.

The governing partial differential equations are transformed to non-dimensional governing equations and are solved using ISPH method. The results present the influences of the Dufour and Soret effects on the fluid flow and heat and mass transfer.

The effects of various physical parameters such as Darcy parameter, permeability ratio, inclination angle of permeability and Rayleigh numbers on the temperature and concentration profiles together with the local Nusselt and Sherwood numbers are presented graphically. The results from the current ISPH method are well-validated and have favorable comparisons with previously published results and solutions by the finite volume method.

A study on heat and mass transfer behavior on an anisotropic porous medium embedded in square cavity/annulus is conducted using Incompressible Smoothed Particle Hydrodynamics (ISPH) method. In the ISPH algorithm, a semi-implicit velocity correction procedure is utilized, and the pressure is implicitly evaluated by solving pressure Poisson equation (PPE). The evaluated pressure has been improved by relaxing the density invariance condition to formulate a modified PPE.