Hassane Naji

Université d'Artois · Civil Engineering Department

A thorough understanding of the solid oxide fuel cell (SOFC) performance and reactants' distribution through modeling and numerical simulation has become essential. In this paper, a comprehensive numerical model based on a lattice-based Boltzmann method was developed to numerically handle gas flow in the partially blocked channel and concentration...

This paper performs a numerical assessment of the porosity effect on heat transfer under forced convection in an open-ended horizontal channel filled with a porous structure and a phase change material (PCM). To take into account forced convection between the solid matrix and the PCM, the dimensionless Darcy-BrinkmanForchheimer equations and the lo...

This paper performs a numerical assessment of the porosity effect on heat transfer under forced convection in an open-ended horizontal channel filled with a porous structure and a phase change material (PCM). To take into account forced convection between the solid matrix and the PCM, the dimensionless Darcy-BrinkmanForchheimer equations and the lo...

A double-diffusive mixed convection within low-turbulent regime in a ventilated cavities filled with an air-CO2 mixture and heated from below has been numerically investigated. The lower wall was sustained at a uniform temperature and CO2-concentration. The vertical and upper walls were kept at external temperature and CO2-concentration. To analyze...

In this study, the synthesis of encapsulated eutectic mixture of capric-stearic acid with titanium dioxide as a shell was realized by Sol-Gel method. The encapsulation with inorganic materials such as titanium dioxide decrease the evaporation and diffusion rates of phase change materials and reduce the reactivity toward the environment. The chemica...

A large eddy simulation study was conducted to investigate the turbulent dynamic structure of a fluid flow in two staggered tube configurations, one is composed of all circular cylinders and the second is composed of circular and square cylinders. The present LES, based on the wall-adapting local eddy viscosity model, has been conducted for ReD = 1...

The aim of this paper is to present a general bibliographic review about recent scientific papers focused on the design and operation of air conditioning systems in green and smart buildings.The suggested review is developed using tools offered by the Scopus academic research directory, with a defined search criteria. Furthermore, the VOSviewer sc...

In this work, the two-dimensional laminar flow and the heat transfer in an open-ended rectangular porous channel (metal foam) including a phase change material (PCM; paraffin) under forced convection were numerically investigated. To gain further insight into the foam pore effect on charging/discharging processes, the Darcy–Brinkmann–Forchheimer (D...

The aim of this paper is to present a general bibliographic review about recent scientific papers focused on the design and operation of air conditioning systems in green and smart buildings.The suggested review is developed using tools offered by the Scopus academic research directory, with a defined search criteria. Furthermore, the VOSviewer sci...

This study deals with the indoor air quality (IAQ) measured and perceived in a demonstration building via a smart sensor. The analysis subject targeted includes the following main air pollutants, viz., CO2, VOCs, formaldehyde, benzene, CO, PM2.5, and comfort parameters such as air temperature, and relative humidity. These were recorded during three...

This study deals with a numerical investigation to assess and compare the thermal and economic performance of two solar tower power systems. It concerns the Molten Salt (MS) and Direct Steam Generation (DSG) technologies used as heat carrier and storage. For this purpose, a 50 MWe solar tower plant without thermal energy storage under the climatic...

This paper performs a numerical analysis of time-dependent forced convection heat transfer in an open-ended straight channel filled with a metal structure and paraffin as a phase change material (PCM). The unsteady two-dimensional governing equations, based on the Darcy-Brinkmann-Forchheimer (DBF) model and the two-energy transport equations (i.e....

This paper performs a numerical analysis of time-dependent forced convection heat transfer in an openended straight channel filled with a metal structure and paraffin as a phase change material (PCM). The unsteady two-dimensional governing equations, based on the Darcy-Brinkmann-Forchheimer (DBF) model and the two-energy transport equations (i.e. l...

Abstract— The graphene oxide (GO) material has attracted much attention for the solar energy applications. This paper reports the synthesis and characterization of partially oxidized graphite oxide (GTO). GTO was obtained by modified Hummers method, which is based on the chemical oxidation of natural graphite. Several samples were prepared with dif...

Phase change materials (PCMs) have the ability to store/release huge latent heat during phase change. When used in the building envelope, the PCM wall panel can potentially enhance building operation by reducing energy requirements to maintain thermal comfort, downsizing heating /cooling equipment and shifting the peak load from the electrical grid...

The mixing improvement by passive control is of wide practical interest. The lobed diffuser, which mixes the primary and secondary streams with high efficiency, has been widely used for heat and mass transfer in the field of fluid engineering. In addition, the jets through lobed generate streamwise vortices, which mix the ambient air and the jet fl...

The aim of this work is to deepen the understanding of the aerodynamics of a diffusion flame in a rotary cement kiln. The kiln is a rotary with a cylindrical shaped, long and equipped with a burner, and it is the seat of a diffusion flame with an axisymmetric turbulent jet. The kiln has a capacity of 8,000 Nm ³ to 13,000 Nm ³ of natural gas and pri...

Purpose A comprehensive investigation on the outlet air position effects on the thermal comfort and air quality has been achieved. In addition, airflow and temperature distributions in ventilated cavities filled with an air-CO 2 mixture with mixed convection are predicted. The airflow enters from the cavity through an opening in the lower side of t...

This study deals with a new type of bifunctional micro-encapsulated phase change (MCP) material, capric-stearic acid / graphene oxide-TiO2, which has been successfully developed by in situ hydrolysis and polycondensation of tetrabutyl titanate and modification of graphene oxide (GO) on the TiO2 doped shell. The use of graphene and doped TiO2 is a p...

A combined experimental and computational study of a turbulent multiple jet from lobed diffusers is performed. The main interest of these multiple lobed jets is to come up with the best configuration that improves the thermal and dynamic homogenization in air diffusion units that can be used for ventilation, heating and air conditioning of resident...

The aim of this study is to improve indoor air quality (IAQ) using an intelligent ventilation for optimal air distribution and energy consumption. For this purpose, we developed a smart multi-sensor. This device measures air pollutants (CO2, CO,VOCs, formaldehyde, PM2.5, and benzene) and comfort parameters (temperature, humidity, noise level and li...

This paper performs a numerical analysis of the natural convection within two-dimensional enclosures (square enclosure and enclosures with curved walls) full of a H2O-Cu nanofluid. While their vertical walls are isothermal with a cold temperature Tc, the horizontal top wall is adiabatic and the bottom wall is kept at a sinusoidal hot temperature. T...

This study is based on the improvement of indoor air quality (IAQ) and occupant comfort in smart buildings. For this purpose we have developed a smart sensor connected with a Raspberry Pi 3 B+ card. This device measures the air pollutants that exist in the demonstrator building (CO2, CO, VOCs, formaldehyde, toluene, PM2.5 and benzene) and the comfo...

Dans ce travail, nous présentons une étude expérimentale et numérique du champ dynamique d’une configuration de jets multiples turbulents à diffuseur muni de lobes, appliqué au confort dans les locaux à usage d’habitation. L’objectif visé est l’amélioration de l’efficacité de la diffusion de l’air dans la zone d’occupation à moindre coût, par un mo...

The integration of new building materials incorporating phase change material (PCM) into the building envelope leads to an increase of the heat storage capacity, which may have an influence on minimizing the cooling demand and heating of the building. This work addresses a thermal performance enhancement of brick walls with incorporated PCMs. The i...

This study deals with ventilation effects on measured and perceived indoor air quality (IAQ) in a demonstrator building where IAQ problems can occur. Unlike outdoor air, indoor air is usually recycled continuously, which makes it trapping pollutants. Indoor air quality (IAQ) is characterized by a pollutants' concentration, as well as air temperatur...

When measuring air permeability in large buildings, many technical issues arise such as thermal draft, zero flow pressures and heterogeneity of pressures. The main objective of this study is to determine the different factors causing the heterogeneity of the pressure during an air permeability test in a large-volume building. An experimental study...

Airtightness is the most important property of building envelopes to understand the ventilation. Airtightness refers to the flow measurement through the building envelope as a function of pressure across the building envelope. This relationship often fits to a power law, which is the most common way of expressing data. However, pressure homogeneity...

Ce projet s’inscrit dans une démarche de maitrise de l’énergie et l’amélioration de la qualité de l’air intérieur/extérieur dans le secteur du bâtiment. Pour minimiser la consommation d'énergie, il est important d'améliorer la recherche sur le refroidissement/chauffage passif et de développer des matériaux intelligents afin d’atteindre de hautes pe...

The aim of this study is to improve indoor air quality (IAQ) using an intelligent ventilation for optimal air distribution and energy consumption. For this purpose, we developed a smart multi-sensor. This device measures air pollutants (CO2, CO,VOC, formaldehyde, PM2.5, and benzene) and comfort parameters (temperature, humidity, noise level and lig...

The aim of this study is to improve indoor air quality (IAQ) using an intelligent ventilation for optimal air distribution and energy consumption. For this purpose, we developed a smart multi-sensor. This device measures air pollutants (CO2, CO,VOC, formaldehyde, PM2.5, and benzene) and comfort parameters (temperature, humidity, noise level and lig...

This paper deals with natural convection flows evolving inside an ended and differentially heated cavity, which is filled either with an air or an air-CO2 mixture. The investigation was conducted through the laminar regime to analyze buoyancy ratio changes' effect on heat and mass transfers both in aiding and opposing flows. The thermal Rayleigh nu...

Morocco's building sector accounts for about 25% of the country's total energy consumption, including 18% for residential and 7% for the services sector. This energy consumption is expected to raise due to the significant rise of household equipment rate in HVAC facilities mainly air-conditioners. This work presents a methodology combining single-o...

This paper presents and discusses numerical simulation of the wind velocity’s effect (0≤Uw≤m.s-1 ) on infiltration rates in an individual building using multi-zone modelling. The governing equations are expressed in terms of unknown pressures at points where flow paths connect. The implementation was achieved using an advanced numerical model, whic...

In this work, we present an experimental and numerical study of a turbulent jet from a lobed diffuser, applied to residential comfort. The main aim is the improvement of the air diffusion efficiency, of the ventilation driving flow in the occupancy zone, with least cost. The experiments have been conducted in a room where the dimensions enable a be...

This article deals with the experimental investigation of multiple interacting jets, which may be interested in many engineering applications such as design of a ventilation supply device. The main objective of this study is to achieve the best configuration for use in ventilation applications. To achieve this, several parameters have been consider...

The reduction of energy consumption in Moroccan buildings is a serious challenge, as it accounts for 25% of total energy consumption in the country. Furthermore, the energy demand is expected to raise because of the substantial development of the building sector and the increase of equipment rate in HVAC facilities. The use of shading devices is on...

This study presents numerical investigation and analysis of carbon dioxide transport (CO2) within an isothermal three-dimensional room using impinging jet ventilation (IJV). The IJV is an effective strategy for use in buildings. The study is carried out under turbulent and transient flow regime. The URANS equations supplemented with energy and conc...

A numerical study has been achieved for turbulent double-diffusive mixed convection inside a ventilated two-dimensional square cavity filled with an air-CO2 mixture. A uniform heat and CO2 contaminant sources are applied on the bottom wall. The vertical and upper walls are fixed at external temperature and CO2 concentration. An external fresh air e...

L’isolation accrue des bâtiments et l’utilisation de certains matériaux et produits sont susceptibles d’accroître les concentrations de contaminants de l’air intérieur en l’absence d’une ventilation efficace. Les systèmes d’aération accusent fréquemment des dysfonctionnements qui limitent fortement leur fiabilité. Les travaux menés ces dernières an...

L’isolation accrue des bâtiments et l’utilisation de certains matériaux et produits sont susceptibles d’accroître les concentrations de contaminants de l’air intérieur en l’absence d’une ventilation efficace. Les systèmes d’aération accusent fréquemment des dysfonctionnements qui limitent fortement leur fiabilité. Les travaux menés ces dernières an...

Ce travail expose les principaux résultats d'une étude numérique du comportement thermique d'un composant de mur intégrant des microcapsules de MCP. D’abord, nous présentons le modèle mathématique considéré qui est basé sur la méthode enthalpique et la solution numérique en utilisant la méthode des volumes finis. Ce modèle a été validé en comparant...

The convection dominated melting of hydrates salts (PCM 27) is investigated numerically using a pressure based finite volume method (FVM) with an enthalpy porosity technique, which allows a fixed-grid solution of the coupled momentum and energy equations, and trace the solid-liquid interface without resorting to other equations or transformations....

In the French “Nord-Pas-de-Calais” region, sediments suspended in runoff waters coming from rural watersheds play a major part in the turbidity of surface waters, silting up of streams, and silting of permanent structures such as canals and ports. One of the main factors in processes limiting sediment transfers is the vegetation cover. Quantitative...

This paper deals with the numerical investigation of heat transfer by mixed convection inside ventilated cavities with supply and exhaust slots, and filled with air under a steady and turbulent flow regime. Four configurations, rated A, B, C and D are considered here, according to the position of the inlet and outlet air ports: A, the inlet is on t...

The time at which the precipitated volume is equal to the initial losses (Pi ), that is, the time corresponding to the start of runoff, is therefore between the two times tT and tP . This time is simply called the initial time (ti ). Note that, in the steady state and in the case of a perfect soil, this time is equivalent to the initial time (tE) d...

The use of phase-change materials (PCM) in building materials is becoming increasingly used in the building sector. However, the presence of certain phenomena such as convection and supercooling may affect the fusion times and, consequently, the design of PCMs. Supercooling can have a noteworthy impact on the system performance. Moreover, convectio...

In the present work, we are interested to the experimental and numerical study of the free turbulent lobed jet, used in residential heating and air conditioning. The objective of our study is the improvement of the diffusion performance of the ventilation driving air flow, in the occupancy zone. The experiments have been conducted in a room where t...

Bioclimatic architecture strategies and solar active systems contribute strongly to the reduction of building energy demand and achieving thermal comfort for its occupants over the whole year. This paper deals with the study of the energy performance improvement of a pilot bioclimatic house located in Algiers (Algeria). First, a series of experimen...

Dans le cadre de la TRI (Troisième Révolution Industrielle), la rénovation énergétique est devenue incontournable pour réaliser des économies d’énergie dans le bâti existant. De ce fait, elle est devenue un impératif écologique et social. L'isolation accrue des bâtiments et l’utilisation de certains matériaux et produits sont susceptibles d'accroît...

The Phase Change Material (PCM) integrated in building envelope can decrease the energy requirement for maintaining thermal comfort by enhancing the thermal energy storage of the wall and the roof. This study deals with numerical and experimental study of the thermal behavior of new plaster composite containing a microencapsulated PCM that can be e...

L’étude vise à concevoir, réaliser et tester un matériau textile isolant intégrant un matériau à changement de phase. L'idée est de concevoir un matériau isolant possédant une capacité de stockage capable de maintenir une ambiance intérieure stable, de stocker l'énergie la journée et la restituer la nuit. Il s’agit de réfléchir à la conception d’un...

This article deals with the numerical simulation of transient thermal behavior of a mortar wall containing a microencapsulated phase change material (PCM) using a hybrid finite volume/enthalpy method. Unlike explicit algorithms, the latent heat source term has been handled implicitly in the enthalpy equation. The current approach has been implement...

This study aimed to numerically investigate the air flow and contaminant dispersion in a ventilated room The URANS equations supplemented with energy and concentration equations are solved using the Stream code. We are targeting primarily the ventilation effectiveness (εc) and the index of indoor air quality (IIAQ). Different displacement and mixin...

This study aimed to numerically investigate the air flow and contaminant dispersion in a ventilated room. The URANS equations supplemented with energy and concentration equations are solved using the Stream code. We are targeting primarily the ventilation effectiveness to remove a contaminant and the index of indoor air quality . Different displace...

Cette étude porte sur l'étude numérique de la convection avec surfusion dans un matériau à changement de phase (MCP) via la méthode de Boltzmann sur réseaux (LBM) à un seul temps de relaxation (SRT). Le traitement de ces phénomènes physiques a été réalisé avec des fonctions de distribution doubles (FDD-LBM) couplée à une formulation enthalpique en...

Ce travail concerne la prédiction numérique de l’évolution spatio-temporelle de la concentration en contaminant dans une cavité ventilée. Dans cette optique, nous avons considéré une cavité ventilée en régime laminaire remplie d’un mélange Air-CO2. Le nombre de Reynolds considéré ici est faible à modéré (100 ≤ Re ≤ 800) avec un nombre de Rayleigh d...

This study presents numerical investigation and analysis of carbon dioxide transport (CO2) within an isothermal three-dimensional room using impinging jet ventilation (IJV). The IJV is an effective strategy for use in buildings. The study is carried out under turbulent and transient flow regime. The URANS equations supplemented with energy and conc...

Nous présentons, dans ce travail une étude expérimentale d’un jet lobé, appliqué au confort dans les locaux à usage d’habitation. L’objectif visé est l’amélioration de l’efficacité de la diffusion de l’air dans la zone d’occupation, par un moyen passif de contrôle de l’écoulement. Le dispositif expérimental réalisé est composé d’un châssis en métal...

This paper deals with the numerical simulation of heat transfer and entropy generation in a 2D square enclosure for convective melting. A thermal lattice Boltzmann method (TLBM) is used to handle the study, which has been conducted for Prandtl numbers from 0.02 to 70 at Rayleigh numbers of 10(4) and 10(5). The results are presented in terms of the...

La présente thèse porte sur la prédiction numérique de l’impact des transferts thermique et massique sur la qualité de l’air et sur le confort thermique à l’intérieur des cavités ventilées ou non et remplies de polluant. En effet, les cavités ventilées sont généralement considérées comme étant une approximation pour la modélisation des locaux venti...

In this study, we numerically examined the interactions among multiple swirling jets mounted in unbalanced positions. The formulation was based on the Reynolds average Navier-Stokes equations. In this study, turbulence was modeled using different turbulence models, i.e., k-e(open) standard, renormalization group, and Reynolds stress model (RSM) to...