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Öğe Activation energy impact on unsteady Bio-convection nanomaterial flow over porous surface(Amer Inst Mathematical Sciences-Aims, 2022) Tahir, Madeeha; Naz, Ayesha; Imran, Muhammad; Waqas, Hasan; Akguel, Ali; Shanak, Hussein; Jarrar, RababNanofluid is an advanced technology to enhance heat transportation. Additionally, the thermal conductivity of nanofluids is high therefore, they are more useful for heat transportation. Evaluation of entropy generation has been a helpful technique for tackling improvements in thermal features because it provides information that cannot be obtained via energy analysis. For thermodynamic irreversibilities, a good approximation is the rate of entropy generation. As a result of a reduction of entropy production, energy transport infrastructure has become more efficient. This study aims to analyse the bioconvective flow of nanofluid flow through a stretching sheet in the occurence of gyrotactic motile microorganisms. A magnetised nanomaterial model with thermophoretic and Brownian diffusion properties is analysed. The impacts of activation energy, temperature dependent and exponential base heat source are investigated in this analysis. The entropy generation of the system is also observed for nanofluid flow. The mathematical model is developed as partial differential equations. The governing equations are reduced to a dimensionless system of ordinary differential equations by applying similarity transformations. The ODEs are tacked numerically with the aid of shooting scheme in commercial software MATLAB. For graphical and numerical results of flow controlling parameters versus subjective fields, the commercial software MATLAB tool bvp4 is used with the shooting scheme. The novelty of this analysis computes numerical computation of bioconvective nanofluid flow with temperature -dependent and exponential base heat source investigated. Furthermore, the consequence of thermal radiation and entropy of the system is considered. The porous medium with activation energy is also taken into consideration. The results show that the velocity field is reduced with increased bioconvection Rayleigh number. The thermal field is increased via an exponential space -based heat source. The concentration is reduced via Lewis number. the microorganisms profile declines for larger bioconvection Lewis number. The Brinkman number Br, magnetic and permeability characteristics all showed a rising trend when plotted against the entropy production rate.Öğe CFD SIMULATION AND OPTIMIZATION OF HEAT TRANSFER ENHANCEMENT IN HEV STATIC MIXERS WITH ROTATED ANGLES FOR TURBULENT FLOWS(Vinca Inst Nuclear Sci, 2023) Kaid, Noureddine; Akgul, Ali; Alkhafaji, Mohammed Ayad; Mohsen, Karrar S.; Asad, Jihad; Jarrar, Rabab; Menni, YounesStatic mixers are becoming increasingly popular because they are energyefficient, cost-effective, and easy to maintain. Mixing is an essential unit operation in many chemical industries. In this study, a modified high efficiency vortex static mixer was used to examine laminar flows in a rectangular duct. To encourage fluid rotation and improve mixing with heat transfer, the modified high efficiency vortex set was rotated by angles of 0 degrees, 5 degrees, 10 degrees, 20 degrees, 25 degrees, and 30 degrees. The Reynolds number varied from 3000 to 8000. The outcomes demonstrated that the performance of the mixing was significantly impacted by the modified high efficiency vortex set. The highest mixing efficiency was achieved with a rotation angle between 15 degrees and 20 degrees. Furthermore, the rotations reduced pressure loss in the system and enhanced heat transfer performance, by creating vortices. These results show how modified high efficiency vortex static mixers can improve mixing and heat transfer efficiency in turbulent flows, with prospective utilization across diverse chemical sectors.Öğe CFD STUDY OF A DUAL-PASSAGE SOLAR COLLECTOR WITH LONGITUDINAL AND TRANSVERSE BAFFLES FOR ENHANCED THERMAL PERFORMANCE(Vinca Inst Nuclear Sci, 2023) Amraoui, Mohammed Amine; Alkhafaji, Mohammed Ayad; Abdullaev, Sherzod; Zearah, Sajad A.; Akgul, Ali; Jarrar, Rabab; Shanak, HusseinThe focus of this research is to investigate the heat transfer performance of a solar flat plate collector by utilizing CFD simulation. To accomplish this, a 3-D model of the collector with an air inlet was created using ANSYS Workbench, and the grid was generated through ANSYS ICEM, ANSYS FLUENT, and ANSYS CFX were then used to obtain comprehensive results. The primary objective of this study is to enhance the efficiency of the solar collector by introducing two fluid-flow paths and comparing the results with those reported in existing literature. These findings will aid in the development of advanced solar collector designs and promote sustainable use of solar energy. Furthermore, the insights gained from this study may inspire further research in the renewable energy technology field. Overall, this research explores the potential of improving the performance of solar flat plate collectors and sheds light on how the use of CFD simulation can facilitate the development of innovative and sustainable energy solutions.Öğe COMPARATIVE ANALYSIS OF SOLAR AIR CHANNELS, z-SHAPED OBSTACLES ADDED TO IMPROVE FLOW STRUCTURE(Vinca Inst Nuclear Sci, 2022) Afif, Benameur; Salmi, Mohamed; Akgul, Ali; Jarrar, Rabab; Asad, Jihad; Menni, YounesThis paper's numerical study, which applies the finite volume approach and SIMPLE algorithm, aims to dynamically analyze airflow through a channel with Z-obstacles. Three distinct models were used to place the Z-barriers inside the channel. According to Demartini et al.'s model (2004) and as depicted in example A from the present analysis, the first Z-barrier (fin) is attached to the top wall (heated) and the second (baffle) to the bottom wall (insulated). The Z-barriers, on the other hand, were positioned in the second model on the same wall (in-line arrangement), either on the top surface (two fins in example B) or on the bottom wall (two baffles in example C). With the help of these studies, fluid dynamics in solar air collectors with barriers will be better understood and designed.Öğe Computational Analysis of the Morphological Aspects of Triadic Hybridized Magnetic Nanoparticles Suspended in Liquid Streamed in Coaxially Swirled Disks(Mdpi, 2022) Qureshi, Zubair Akbar; Bilal, Sardar; Shah, Imtiaz Ali; Akguel, Ali; Jarrar, Rabab; Shanak, Hussein; Asad, JihadCurrently, pagination clearly explains the increase in the thermophysical attributes of viscous hybrid nanofluid flow by varying morphological aspects of inducted triadic magnetic nanoparticles between two coaxially rotating disks. Copper metallic nanoparticles are inserted with three different types of metallic oxide nanoparticles: Al2O3, Ti2O, and Fe3O4. Single-phase simulation has been designed for the triadic hybrid nanofluids flow. The achieved expressions are transmuted by the obliging transformation technique because of dimensionless ordinary differential equations (ODEs). Runge-Kutta in collaboration with shooting procedure are implemented to achieve the solution of ODEs. The consequences of pertinent variables on associated distributions and related quantities of physical interest are elaborated in detail. It is inferred from the analysis that Cu-Al2O3 metallic type hybrid nanofluids flow shows significant results as compared with the other hybrid nanoparticles. The injection phenomenon on hybrid nanofluids gives remarkable results regarding shear stress and heat flux with the induction of hybridized metallic nanoparticles. Shape and size factors have also been applied to physical quantities. The morphology of any hybrid nanoparticles is directly proportional to the thermal conductance of nanofluids. Peclet number has a significant effect on the temperature profile.Öğe NUMERICAL INVESTIGATION OF THE INTERACTION BETWEEN THE ROUGHNESS AND THE TRIANGULAR OBSTRUCTIONS IN A RECTANGULAR CHANNEL(Vinca Inst Nuclear Sci, 2023) Sari Hassoun, Zakaria; Aliane, Khaled; Akgul, Ali; Jarrar, Rabab; Asad, Jihad; Menni, Younes; Ahmad, HijazThe study is conducted around a heat exchanger, its channel is horizontal rect-angular, its upper wall is isothermal, while its lower wall is thermally insulated, containing extended surfaces in the form of triangular obstacles attached in a stag-gered manner periodically. Four models of the channel with various roughnesses were compared in this study. Square, triangular Type 1, triangular Type 2, and triangular Type 3 roughnesses, which are positioned on the hot top part of the channel (absorber), downstream of the last obstacle, are examined to promote heat transfer between the absorber and the heat transfer fluid. The case of triangular roughness (Type 3) is the optimal case in terms of improved heat transfer. More-over, it shows a significant decrease in terms of friction values.Öğe Numerical solution of MHD Casson fluid flow with variable properties across an inclined porous stretching sheet(Amer Inst Mathematical Sciences-Aims, 2022) Rddy, K. Veera; Reddy, G. Venkata Ramana; Akgul, Ali; Jarrar, Rabab; Shanak, Hussein; Asad, JihadThe dynamics of Casson nanofluid with chemically reactive and thermally conducting medium past an elongated sheet was investigated in this work. Partial differential equations were used in the flow model (PDEs). The governing equations can be converted into system of ordinary differential equations. Using the R-K method and shooting techniques, the altered equations were numerically resolved. The impact of relevant flow factors was depicted using graphs while computations on engineering quantities of interest are tabulated. The velocity profiles were observed to degrade when the visco-inelastic parameter (Casson) and magnetic parameter (M) were set to a higher value. An increase in magnetic specification's value has been observed to decrease the distribution of velocity. A huge M value originates the Lorentz force which can degenerate the motion of an electrically conducting fluids. Physically, the multiplication of electrical conductivity (??????) and magnetic force's magnitude possess electromagnetic force which drag back the fluid motion. As a result, as Gm rises, the mass buoyancy force rises, causing the velocity distribution to widen. The contributions of variable thermal conductivity and variable diffusion coefficient on temperature and concentration contours respectively have been illustrated. The boundary layer distributions degenerate as the unsteadiness parameter (A) is increased. The outcomes of this agrees with previous outcomes.Öğe OPTIMIZING SOLAR WATER HEATER PERFORMANCE THROUGH A NUMERICAL STUDY OF ZIG-ZAG SHAPED TUBES(Vinca Inst Nuclear Sci, 2023) Korti, Mohammed Choukri; Youcef, Ahmed; Akgul, Ali; Alwan, Adil Abbas; Mohsen, Karrar S.; Asad, Jihad; Jarrar, RababThis study aimed to investigate the thermal behavior of water flows in a solar collector equipped with zig-zag tubes. To achieve this, a numerical simulation using CFD was conducted, which is a powerful tool for analyzing fluid-flow and heat transfer. The simulation employed the finite volume method to discretize the fluid domain and the SIMPLE algorithm to solve the pressure-velocity coupling. The simulation results indicated that the shape of the tubes significantly influenced the flow behavior and overall performance of the solar collector. Specifically, the temperature profiles at various times of the day showed that zig-zagshaped tubes enhanced the heat transfer coefficient, resulting in higher temperatures within the collector. Moreover, the zig-zag design increased the residence time of the fluid inside the collector, further improving its overall efficiency. These findings highlight the potential of utilizing zig-zag-shaped tubes to optimize the performance of solar water heating systems, which could have important implications for renewable energy applications.Öğe THREE-DIMENSIONAL ASSESSMENT OF THERMAL-HYDRAULIC BEHAVIOUR IN HEAT EXCHANGERS FITTED BY WAVY ANNULAR FINS(Vinca Inst Nuclear Sci, 2022) Djeffal, Fares; Tahrour, Farouk; Bordja, Lyes; Akgul, Ali; Jarrar, Rabab; Asad, Jihad; Menni, YounesIn this study, numerical studies to clarify the influence of wave number and amplitude on thermal-flow behavior of wavy annular finned-and-tube heat exchangers are described. For a range of Reynolds number from 4400 to 14300, the influence of wave amplitude, 1.5 <= A <= 4.5 mm, and wave numbers, 2 <= N-w <= 6, on forced convection heat transfer was examined. It was revealed that the wave amplitude and number have an impact on the heat flux, Colburn factor, and friction factor. The wavy annular-fins with a 3 mm amplitude and N-w = 4 waves obtained the highest values at all Reynolds numbers in terms of the overall performance criterion (j/f(1/3)).Öğe TURBULENT FLOWS AROUND RECTANGULAR AND TRIANGULAR TURBULATORS IN BAFFLED CHANNELS A Computational Analysis(Vinca Inst Nuclear Sci, 2022) Salmi, Mohamed; Afif, Benameur; Akgul, Ali; Jarrar, Rabab; Shanak, Hussein; Menni, Younes; Ahmad, HijazThe present paper highlights a computational analysis of air-flows around rectangular and triangular turbulators inside baffled heat exchanger channels in order to improve heat transfer between the fluid and their heated areas. The dynamic and thermal fields as well as fluid temperature curves at the outlet of the exchanger are studied. The computational study is conducted by utilizing SIMPLE algorithm with FLUENT system based on the finite volumes. The analysis clearly demonstrated the presence of highly turbulent flows and the appearance of many vortices in various regions of the exchanger. By comparing the different heat exchangers, it was found that the baffled channel fitted with rectangular turbulators produced high fluid temperature values at the channel outlet, indicating the significance of using this rectangular form of turbulators in order to enhance the interaction between the hot spaces and the used fluid.
