Browsing by Author "Ameziani, Djamel Eddine"

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Analysis of a reactive porous separation effects on depollution and indoor air quality: Application of LBM-MRT to heat and mass transfers
(Elsevier, 2024) Arab, Assia; Himrane, Nabil; Hireche, Zouhira; Halouane, Yacine; Bennacer, Rachid; Ameziani, Djamel Eddine
The reduction of energy demand and the indoor air quality associated with energy demand are the main goals of thermal buildings. This work is devoted to the study of the effect of a reactive porous separation on the ventilation (cooling) and depollution capacity in a rectangular room ventilated by air displacement. The model is considered as a cavity heated on its right verticle wall and thermally isolated by the other three walls. A porous separation divides the room into two compartments. The system of equations was solved using the Lattice Boltzmann method with multiple relaxation times. The extended Darcy Brinkman-Forchheimer model was used to simulate the porous material. An additional linear term is added to the standard transport equations (material diffusion) to account for reaction effects, this term was derived from Arrhenius' law. Over a wide range of Richardson and Darcy numbers, the results of the computations show the influence of these parameters on the flow structure, making it possible to categorize the different convection phenomena (natural, forced and mixed). The most important point to note is that the addition of reaction (fixing reaction) improves indoor air quality and can achieve a 55 % reduction in air renewal time, thus saving on energy costs. However, this reactif effect has no influence on the thermal efficiency of the proposed model.
LBM-MRT study of a reactive porous separation on thermal and depollution efficiency in a ventilated room
(Elsevier Ltd, 2024) Arab, Assia; Himrane, Nabil; Ameziani, Djamel Eddine; Hireche, Zouhira; Halouane, Yacine; Magherbi, Mourad
This work investigates a mixed laminar thermosolutal convection phenomenon in a cavity ventilated by air displacement, equipped with a reactive porous separation of variable height inside. The Lattice Boltzmann method with multiple relaxation times (LBM-MRT) was adopted for the mathematical resolution. The extended Darcy Brinkman-Forchheimer model was used to simulate the porous material. The objective of this work is to improve the energy efficiency of ventilation systems and optimize indoor air quality. The main novelty of this research lies in the introduction of a complement to ventilation, in the form of a fixation reaction, making it possible to develop a physical model based on both the elimination and fixation of pollutants. The model represents a rectangular cavity with heating one of its vertical walls, while the other walls are adiabatic. The geometric and flow parameters examined are the height of the porous separation (Hp), its permeability (Darcy number), the fixing reaction rate (Ak) and the Reynolds Reas well as the Rayleigh Ra numbers. The most notable result concerns the estimated improvement of around 52% in thermal efficiency. This occurs in the case of a high Darcy number (Da=10−2), a height of 0.3, a moderate flow rate (Rec=5×102) and maximum thermal heating (Ra=106). This improvement is compared to case with a low Darcy value (Da=10−6). In the same scenario, the thermal efficiency reaches its peak at a height of 0.9. The results show that the impact of the fixation reaction and the height Hp is most noticeable at low permeabilities (low Da), as the porous separation acts as a solid wall. As a result, an increase in Hp leads to an expansion of the dead zone in the second compartment, creating a zone that is both polluted and thermally uncomfortable.
Time-Periodic cooling of Rayleigh–Bénard convection
(MDPI AG, 2021) Nasseri, Lyes; Himrane, Nabil; Ameziani, Djamel Eddine; Bourada, Abderrahmane; Bennacer, Rachid
The problem of Rayleigh–Bénard’s natural convection subjected to a temporally periodic cooling condition is solved numerically by the Lattice Boltzmann method with multiple relaxation time (LBM-MRT). The study finds its interest in the field of thermal comfort where current knowledge has gaps in the fundamental phenomena requiring their exploration. The Boussinesq approximation is considered in the resolution of the physical problem studied for a Rayleigh number taken in the range 103 ≤ Ra ≤ 106 with a Prandtl number equal to 0.71 (air as working fluid). The physical phenomenon is also controlled by the amplitude of periodic cooling where, for small values of the latter, the results obtained follow a periodic evolution around an average corresponding to the formulation at a constant cold temperature. When the heating amplitude increases, the physical phenomenon is disturbed, the stream functions become mainly multicellular and an aperiodic evolution is obtained for the heat transfer illustrated by the average Nusselt number