Publications Scientifiques

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    Experimental investigation of a novel heat exchanger for optimizing heat transfer performance using Al2O3‑water nanofluids
    (Springer, 2023) Hamidatou, Smail; Nadir, M.; Togun, Hussein; Azher, M. Abed; Deghoum, K.; Hadjad, A.; Goodarz, Ahmadi
    This study presents an experimental investigation to determine the heat transfer enhancement in a novel heat exchanger known as the "Helicoidal Square-Shaped Heat Exchanger" with and without using a nanofuid. The experiments were performed for the range of Reynolds numbers from 4400 to 8000, using nanofuid (Al2O3-pure water) at the concentrations 0.1, 0.25, and 0.5%. This experimental investigation found that the heat transfer ratio is improved by increasing the nanofuid concentrations and the fow Reynolds number. The highest value of the heat transfer ratio was at Re = 8000, and 0.5% concentration of nanofuids. The corresponding increment in the heat transfer rate was 13.46 %, the heat transfer coefcient augmented by 9.64 %, and the Nusselt number improved by 10.43% compared to the results obtained experimentally with distilled water. The results obtained for the distilled water were verifed with the Dittus-Boelter equation and numerical simulation. In addition, all obtained experimental data were compared with the CFD simulation. The use of nanofuids for heat transfer enhancement has a wide range of applications. Therefore, the presented results suggest using Al2O3-water nanofuids to improve the efciency of many renewable energy plants, including solar and geothermal energy systems.
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    Development of a thermodynamic model for supercharged diesel engine performance and combustion characteristics study
    (Taylor and Francis Ltd, 2023) Nezlioui, Ferroudja; Benslimane, Abdelhakim; Hamtache, Brahim; Sahi, Adel; Lounici, Mohand Said; Sadaoui, Djamel
    Development of a model that allows performance and combustion characteristics for a supercharged diesel engine was the main objective sought by the present work. Thus, the developed model is used, to examine the impact of start combustion, combustion duration, compression ratio, and heat flux, as well as intake conditions such as pressure and temperature, on the combustion characteristics of the supercharged diesel. For this purpose, a one zone thermodynamic prediction model was adopted with Wiebe function for combustion sub-model. The heat transfer was correlated using Woschni correlation. A numerical simulation is developed considering the crankshaft angle as the independent variable. Validation of the computational code has been favorably evaluated using our experimental data. To give a more general aspect to the developed model, experimental data found in the literature, are also used for this purpose. The results show that the addition of a turbocharger increases low-speed airflow and hence fuel consumption. In addition, an increase in intake pressure contributes to the rise of the heat flux released during combustion, while an increase in intake temperature leads to a strong increase in combustion temperature. Moreover, an increase in the compression ratio leads in a remarkable increase in all parameters simultaneously. However, maximum combustion pressure limits must not be exceeded. This is because the pressure has an effect with the engine mechanical strength.
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    Impact of upward turbulent flow on wax deposition in heavy viscous oil pipelines: A numerical simulation
    (International Information and Engineering Technology Association, 2023) Benhacene, Oussama; Boucetta, Rachid
    Wax deposition in crude oil pipelines is a significant challenge that escalates under turbulent flow conditions. This phenomenon is initiated by the cooling of crude oil during its conveyance, causing wax constituents to solidify and adhere to the pipeline walls via molecular diffusion. This study embarks on an investigation of the impact of fluid flow velocity on wax accumulation in pipelines transporting heavy, viscous, and wax-laden fluids, such as crude oil. A rigorous exploration of this behavior was conducted, intertwining fundamental principles from fluid dynamics, heat transfer, and mass transport. The resultant complex governing equations were tackled utilizing numerical approaches. Our findings reveal a notable trend: an acceleration in fluid flow speed prompts an increase in pipeline wax deposition. The outcomes of this study bear substantial implications for pipeline management and construction, underlining the necessity to account for flow velocity to optimize operations, minimize maintenance, and promote cost-effective transportation of heavy, viscous fluids. This research initiates a critical conversation on the role of flow velocity in wax deposition, opening avenues for future investigations and potential mitigation strategies.
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    Poiseuille-Rayleigh-Bénard mixed convection flow in a channel : Heat transfer and fluid flow patterns
    (Elsevier, 2021) Taher, Rani; Ahmed, Mohamed Mohsen; Haddad, Zoubida; Abid, Cherifa
    In the present work, a numerical and experimental study of mixed convection of water flow in a horizontal channel subjected to a constant heat flux is presented. An experimental setup was constructed to delineate the fluid flow patterns inside the channel, while a numerical simulation was performed to study the heat transfer characteristics of the flow. This study is performed for Rayleigh and Reynolds numbers in the range of 104 ≤ Ra≤ 106 and 25≤ Re≤ 100, respectively. The present predicted results are in good agreement with the experimental ones. The longitudinal evolution rolls revealed the existence of four zones corresponding to the entry zone, establishment zone, destabilization zone, and turbulent zone. Moreover, numerical simulations showed that the Nusselt number for the mixed convection gives higher heat transfer coefficient compared to forced convection. In addition, new correlations for the Nusselt number have been developed for the first time for the establishment length, onset and established zones as a function of Rayleigh and Reynolds numbers
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    Magnetohydrodynamic effect on flow structures between coaxial cylinders heated from below
    (American Institute of Aeronautics and Astronautics Inc., 2020) Mahfoud, B.; Benhacine, H.; Laouari, A.; Bendjaghlouli, A.
    Numerical simulationswereperformedinordertostudycombinedforcedandnaturalconvectionflowbetweentwo coaxial vertical cylinders under an axial magnetic field. The effects of the axial magnetic field and six annular gaps on flow structures and heat transfer were assessed. The governing Navier-Stokes, energy, and potential equations are solved by using the finite volume method. The three-dimensional symmetry breaking of the basic state appears as the annular gaps become larger. Asymmetric m = 1 and 2 azimuthal modes are observed. Finally, our results show that the magnetic field controls both the heat transfer and the transition to asymmetry flow. © 2019 by the American Institute of Aeronautics and Astronautics, Inc.
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    Effect of turbulence models' choice on the aero-thermal flow numerical validations within a ribbed trailing edge geometry
    (Sage, 2019) Beniaiche, Ahmed; Nadir, Mahmoud; Mahfoudh, Cerdoun; Carcasci, Carlo; Facchini, Bruno
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    Comparison of turbulent forced convection between wall jet and channel flow over a heated obstacle
    (Inderscience, 2017) Kabache, Malika; Mataoui, Amina; Oztop, Hakan F.
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    Heat transfer prediction of a jet impinging a cylindrical deadlock area
    (American Society of Mechanical Engineers (ASME), 2014) Halouane, Yacine; Mataoui, Amina; Iachachene, Farida