Abbes Azzi | University of Sciences and Technology-Oran- Mohamed Boudiaf (USTOMB). (original) (raw)

Papers by Abbes Azzi

Procedia Engineering, 2015

Asian Journal of Applied Sciences, Jun 7, 2014

In this work, we intend to solve numerically the impact of the coupling of convection-radiation f... more In this work, we intend to solve numerically the impact of the coupling of convection-radiation for a cylindrical and an annular cylindrical configuration in order to improve this heat transfer. For that, we subject the cylinder external with a constant parietal heat flow. The numerical resolution of this system related to their limited conditions was carried out by the finite differences method making it possible to simulate the radiative effect in the annular cylindrical space. Therefore, the aim of our study is to recreate at low-temperature, radiative effects being able to improve the heat transfers in flow patterns (parallel plates and annular cylindrical spaces), representative of the ones seen in electronics or electrotechnics. The results obtained show the absorption of the black body introduced for various positions of the intermediate wall.

Zenodo (CERN European Organization for Nuclear Research), 2017

Journal of Urban and Environmental Engineering, Jan 21, 2016

In this paper the sea breeze dynamics in Oran agglomeration atmosphere, in the north Algeria, is ... more In this paper the sea breeze dynamics in Oran agglomeration atmosphere, in the north Algeria, is investigated and analyzed by a numerical simulation of Oran agglomeration atmosphere, using SUBMESO model during diurnal cycle of June 24, 2010, in order to predict the spatio-temporal starting of sea breeze, its intensity and relative direction through atmospheric flow variations analysis, and to evaluate the role of thermal circulations on sea breeze direction, intensity and ventilation and its effect on pollutant transport. The study of this area has not been investigated or analyzed in any framework, the numerical simulation was preceded by a topographic and surface data processing in order to generate the grid simulation, with a specific characteristics used by the SUBEMESO and SM2-U (Soil Model for Sub-Meso scales Urbanized) models. This simulation allowed us to know all sea breeze characteristics during the study period.

International Journal on Environmental Sciences, 2014

The present study aims to investigate and analyse the origin of polluted air masses coming to the... more The present study aims to investigate and analyse the origin of polluted air masses coming to the North Africa during the period 28–29 of July 2013. In this order, an advanced photochemical model was performed to simulate the transformation and the transport of the main important pollutant i.e. O3 and NOx cover the entire Western Mediterranean Region. The photochemical model results of the both day simulated are compared with observed data and it show a good concordance about the O3 and NOx. In addition, the Long range transport of pollutants from Europe resulted in O3. To better understand this last, a CAMx Tracer was carried out during 48 hour, the tracer-mapped ozone values and dispersion show reasonable agreement with wind direction.

HAL (Le Centre pour la Communication Scientifique Directe), Aug 26, 2013

In the present study a numerical investigation is carried out using the SarahCFD code which is an... more In the present study a numerical investigation is carried out using the SarahCFD code which is an in house CFD code based on finite volume method. The application case is unsteady natural convection inside a closed differentially heated cavity (L=1m, H=0.24) with a thin fin adjacent to the heated wall. For comparison purpose, three cases are considered. The first one is a classical differentially heated cavity, which will be used as reference case. The second and the third cases are mounted with a thin fin at the hot sidewall. The fin is respectively adiabatic and conducting. Only the early unsteady stage (up to 10 seconds) is presented in the present paper. Temporal development and spatial flow structures in the vicinity of the fin are presented and shows clearly the improvement of heat transfer rate for the conducting fin case.

Air Quality, Atmosphere & Health, Jan 23, 2015

ABSTRACT Model simulations of tropospheric NO2 vertical column density are performed using the on... more ABSTRACT Model simulations of tropospheric NO2 vertical column density are performed using the online-coupled BOLCHEM model. Model output is compared to ozone monitoring instrument (OMI) data from the Tropospheric Emission Monitoring Internet Service (TEMIS) over Europe for the year 2007. European hot-spots (Po Valley and BeNeLux) are simulated at finer resolution and analysed separately, along with the area of Gibraltar. Standard statistical analysis reveals good model performances, even in highly polluted regions, with spatial correlation 0.90 for the whole of Europe, 0.74 for the Po Valley, 0.85 for BeNeLux and 0.79 for Gibraltar. Seasonal analysis shows some dependency on time, with lowest scores in winter, when the satellite product also suffers weaker statistical significance due to the presence of clouds. The increase in resolution is found to affect the spatial correlation more the Po Valley (+23 %) than in BeNeLux (+5 %). This difference is likely to depend on the very different meteorology of the two hot-spots.

International Journal of Heat and Mass Transfer, May 1, 2002

In the present work, a numerical study of the effect of a hot wavy wall of a laminar natural conv... more In the present work, a numerical study of the effect of a hot wavy wall of a laminar natural convection in an inclined square cavity, differentially heated, was carried out. This problem is solved by using the partial differential equations, which are the vorticity transport, heat transfer and stream function in curvilinear coordinates. The tests were performed for different inclination angles, amplitudes and Rayleigh numbers while the Prandtl number was kept constant. Two geometrical configurations were used namely one and three undulations. The results obtained show that the hot wall undulation affects the flow and the heat transfer rate in the cavity. The mean Nusselt number decreases comparing with the square cavity. The trend of the local heat transfer is wavy. The frequency of the latter is different from the undulated wall frequency.

Microelectronics Reliability, Jun 1, 2015

A Computational Fluid Dynamic (CFD) study based on Reynolds Averaged Navier-Stokes (RANS) approac... more A Computational Fluid Dynamic (CFD) study based on Reynolds Averaged Navier-Stokes (RANS) approach is carried out to predict the mean velocity field and the heat transfer rate of an impinging jet in cross-flow configuration on a heated wall-mounted cube. Targeting an electronic cooling configuration, the aim is to investigate the effect of geometrical modification of the component on the cooling effectiveness. For the same cross flow Reynolds number Re H = 3410, three levels of impinging jets are computed as well as a case without impinging jet that will serve as baseline case for comparison. The results from the RANS computation are compared to experimental data from published scientific literature. The validation shows qualitatively good agreement and almost all flow structures are well reproduced by the computation. In an attempt to optimize the wall heat flux over the cube surface, a new geometry is proposed without sharp corners on the top cube face. Numerical results show that with minor geometrical modification (chamfer), the fluid flow structure around the electronic component is radically transformed and the heat transfer rate can be improved. The highest cooling effectiveness improvement is realize for the highest Reynolds number ratio Re j /Re H = 1.5 and for the chamfer height of 4 mm.

Applied Journal of Environmental Engineering Science, Mar 31, 2018

This work reports three-dimensional simulation results of thermal mixing in rectangular T-junctio... more This work reports three-dimensional simulation results of thermal mixing in rectangular T-junction configuration at high Reynolds number. The validation data are provided by an experimental study done at

Journal of Fundamental and Applied Sciences, 2018

Different passive control methods are discussed in this paper with the purpose of improved the qu... more Different passive control methods are discussed in this paper with the purpose of improved the quality of the air and dispersed the pollution outside the urban canyon road. Numerical investigation model is used in this paper, to examine two methods of passive control within a crossing under building and Low Boundary Wall in center of road for reducing air pollution concentration using Reynolds-averaged Navier-Stokes equations and the k-Epsilon turbulence model as close of the equation system. The results of this investigation show that a low boundary wall located at the central median of the street canyon creates a significant reduction in pedestrian exposure, relative to the same canyon with no wall. The magnitude of the exposure reduction was also found to vary according to the numbers of the crossing under building in the street canyon geometry. The values of the concentration normalized is decreased in the critical region were located in the centerline of the street canyon.

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2014 (ICNAAM-2014), 2015

We report three-dimensional simulation results of thermal mixing in square T-junction configurati... more We report three-dimensional simulation results of thermal mixing in square T-junction configuration at high Reynolds number. The square T-junction configuration with different channel sizes was studied experimentally at the Department of Mechanical Engineering of Mie University, Japan. The T-Junction was selected as a benchmark for thermal mixing in the ERCOFTAC Workshop held in EDF Chatou, France, 2011. RANS, URANS and SAS simulations were performed with CFD code using finite volume method The comparison shows excellent agreement between SAS and the data.

Defect and Diffusion Forum, May 1, 2021

This paper deals with studying numerically two circular turbulent jets impinging on a flat surfac... more This paper deals with studying numerically two circular turbulent jets impinging on a flat surface with a low velocity cross flow by using ANSYS CFX 16.2, with the aim of proving the effect ofReynolds number on the flow demeanor in a vertical circular free turbulent jet with cross flow. Five turbulence models of the RANS (Reynolds Averaged Navier–Stokes) approach were tested and the k -ω SST model was chosen to validate CFD results with the experimental data. Average velocity profiles, velocity and turbulent kinetic energy contours and streamlines are presented for four case configurations. In the first three cases, the following parameters have been varied: Reynolds number at the level of the two jets ( ), wind velocity at the level of the cross-flow ( ), and the distance between the two jets (S = 45mm, 90mm and 135mm). In the last case, a new configuration of the phenomenon not yet studied so far was treated, where horizontal cross-flows were introduced from both sides in order to simulate gusts of wind disrupting a VSTOL aircraft which tries to operate close to the ground. This case was carried out for Reynolds number based on the crossflow of 4 104, 10 104 and 20 104 .The numerical results obtained show that the deflection of the jets is minimal when the Reynolds number at the level of the jets is greater than that of the cross-flow. The increase of Reynolds number at the level of the cross-flow reveals a significant deviation of the two jets with an intensity which always remains less for the second jet. As for the space parameter between the two jets, it turns out that the fact of further spacing the two jets makes the first jet even more vulnerable and leads to a greater deflection. Finally, the simulation of the wind gusts from the front and the back caused a zone of turbulence which resulted from a form of "interlacing" of the two jets under the effect of the transverse current imposed by the two sides.

ABSTRACT Les performances du modèle de turbulence de second ordre proposé par [1] et noté SSG-RSM... more ABSTRACT Les performances du modèle de turbulence de second ordre proposé par [1] et noté SSG-RSM Model sont testées pour modéliser le phénomène du refroidissement par film appliqué sur le bord d’attaque d’une aube symétrique de turbine à gaz. Pour compléter l’étude le même calcul est réalisé par l’utilisation du modèle standard k-ε et les résultats des deux simulations sont comparés aux mesures expérimentales disponibles dans la littérature. La présente étude est réalisée à l’aide du code de calcul ANSYS CFX 5.7.1. Le cas étudié est une aube de turbine à gaz de forme symétrique munie de deux rangées de trous d’injection cylindrique positionnée de part et d’autre du bord d’attaque. Dans la présente étude, trois taux d’injection ont été testés et les résultats obtenus sous forme de contours de l’efficacité de refroidissement sur la surface de l’aube et l’efficacité latérale moyenne ont été comparés avec succès aux résultats expérimentaux.

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2014 (ICNAAM-2014), 2015

This paper investigates the effect of the pulsating film cooling at the leading edge of a symmetr... more This paper investigates the effect of the pulsating film cooling at the leading edge of a symmetrical turbine blade model. Numerical finite volume method is used to resolve the Unsteady Reynolds Averaged Navier Stokes Equations coupled at turbulence model. Detailed numerical film cooling effectiveness have been made for both steady and pulsating flows. The test case blade model is symmetric and has one injection row of discrete cylindrical holes on each side near the leading edge. Jet pulsing frequencies of 5 Hz, 10 Hz, and 20 Hz have been studied. The computational domain is discretized using a highly refined multi-bloc structured grid including the plenum area. The turbulence field is resolved by use of the SST turbulence Model. The numerical simulations are conducted for three different blowing ratios of 0.3, 0.5, and 0.7; film cooling effectiveness contours on the blade surface and lateral averaged adiabatic film cooling effectiveness are presented and the continuous jet results compared with availabl...

Computational Thermal Sciences, 2018

Dans cette étude, une investigation numérique est réalisée pour évaluer l'efficacité de la techni... more Dans cette étude, une investigation numérique est réalisée pour évaluer l'efficacité de la technique des trous latéraux (Anti-vortex) du refroidissement par film. Ce concept d'anti-vortex est développé et étudié au centre de recherche de la NASA Glenn. Il est conçu pour atténuer les effets contre-rotatifs qui sont la cause de la réduction de l'efficacité de refroidissement par film au taux d'injections élevés. Cette conception d'antivortex consiste en deux trous secondaires de refroidissement à côté du trou principal. Ces deux trous sont légèrement en aval du point central du trou principal de telle façon que l'injection secondaire détruit le deux vortex contra rotatif (Kidney Vorticies). L'avantage de cette conception est la réduction des vorticités indésirables et l'amélioration de l'efficacité du refroidissement par film. Cette investigation d'anti-vortex est réalisée par un code commercial résolvant les équations de Navier-Stokes et l'équation de l'énergie moyennant la méthode des volumes finis (ANSYS CFX 12.0). Le domaine de calcul est discrétisé en utilisant un maillage hexa incluant la partie refroidie, les trous d'injection et la boite d'alimentation. La turbulence est résolue avec le modèle de premier ordre SST. Deux configurations géométriques combinées avec des taux d'injections élevés et des rapports de masse volumiques variables sont considérés. Il a été trouvé que les trous latéraux améliorent la performance du refroidissement à travers tous le domaine de calcul. Les résultats numériques des trous équipés de la conception d'anti-vortex sont comparés avec le cas de base où l'injection se fait à travers un seul trou rond Sinha et al. (1991). Les résultats numériques montrent aussi une amélioration prometteuse dans tous les aspects thermo-fluide.

Springer eBooks, 2007

In this contribution we intend to present a summary of a joint European project in frame of MEDA-... more In this contribution we intend to present a summary of a joint European project in frame of MEDA-TEMPUS program. The main aim of this project is to set up in Algeria (USTO University) a Master Degree that will focus on Air Pollutant Dispersion Modelling. To the best knowledge of the author, this is the first time that this level of

Journal of Applied Sciences, Jul 15, 2005

Computational Thermal Sciences, 2016

Procedia Engineering, 2015

Asian Journal of Applied Sciences, Jun 7, 2014

In this work, we intend to solve numerically the impact of the coupling of convection-radiation f... more In this work, we intend to solve numerically the impact of the coupling of convection-radiation for a cylindrical and an annular cylindrical configuration in order to improve this heat transfer. For that, we subject the cylinder external with a constant parietal heat flow. The numerical resolution of this system related to their limited conditions was carried out by the finite differences method making it possible to simulate the radiative effect in the annular cylindrical space. Therefore, the aim of our study is to recreate at low-temperature, radiative effects being able to improve the heat transfers in flow patterns (parallel plates and annular cylindrical spaces), representative of the ones seen in electronics or electrotechnics. The results obtained show the absorption of the black body introduced for various positions of the intermediate wall.

Zenodo (CERN European Organization for Nuclear Research), 2017

Journal of Urban and Environmental Engineering, Jan 21, 2016

In this paper the sea breeze dynamics in Oran agglomeration atmosphere, in the north Algeria, is ... more In this paper the sea breeze dynamics in Oran agglomeration atmosphere, in the north Algeria, is investigated and analyzed by a numerical simulation of Oran agglomeration atmosphere, using SUBMESO model during diurnal cycle of June 24, 2010, in order to predict the spatio-temporal starting of sea breeze, its intensity and relative direction through atmospheric flow variations analysis, and to evaluate the role of thermal circulations on sea breeze direction, intensity and ventilation and its effect on pollutant transport. The study of this area has not been investigated or analyzed in any framework, the numerical simulation was preceded by a topographic and surface data processing in order to generate the grid simulation, with a specific characteristics used by the SUBEMESO and SM2-U (Soil Model for Sub-Meso scales Urbanized) models. This simulation allowed us to know all sea breeze characteristics during the study period.

International Journal on Environmental Sciences, 2014

The present study aims to investigate and analyse the origin of polluted air masses coming to the... more The present study aims to investigate and analyse the origin of polluted air masses coming to the North Africa during the period 28–29 of July 2013. In this order, an advanced photochemical model was performed to simulate the transformation and the transport of the main important pollutant i.e. O3 and NOx cover the entire Western Mediterranean Region. The photochemical model results of the both day simulated are compared with observed data and it show a good concordance about the O3 and NOx. In addition, the Long range transport of pollutants from Europe resulted in O3. To better understand this last, a CAMx Tracer was carried out during 48 hour, the tracer-mapped ozone values and dispersion show reasonable agreement with wind direction.

HAL (Le Centre pour la Communication Scientifique Directe), Aug 26, 2013

In the present study a numerical investigation is carried out using the SarahCFD code which is an... more In the present study a numerical investigation is carried out using the SarahCFD code which is an in house CFD code based on finite volume method. The application case is unsteady natural convection inside a closed differentially heated cavity (L=1m, H=0.24) with a thin fin adjacent to the heated wall. For comparison purpose, three cases are considered. The first one is a classical differentially heated cavity, which will be used as reference case. The second and the third cases are mounted with a thin fin at the hot sidewall. The fin is respectively adiabatic and conducting. Only the early unsteady stage (up to 10 seconds) is presented in the present paper. Temporal development and spatial flow structures in the vicinity of the fin are presented and shows clearly the improvement of heat transfer rate for the conducting fin case.

Air Quality, Atmosphere & Health, Jan 23, 2015

ABSTRACT Model simulations of tropospheric NO2 vertical column density are performed using the on... more ABSTRACT Model simulations of tropospheric NO2 vertical column density are performed using the online-coupled BOLCHEM model. Model output is compared to ozone monitoring instrument (OMI) data from the Tropospheric Emission Monitoring Internet Service (TEMIS) over Europe for the year 2007. European hot-spots (Po Valley and BeNeLux) are simulated at finer resolution and analysed separately, along with the area of Gibraltar. Standard statistical analysis reveals good model performances, even in highly polluted regions, with spatial correlation 0.90 for the whole of Europe, 0.74 for the Po Valley, 0.85 for BeNeLux and 0.79 for Gibraltar. Seasonal analysis shows some dependency on time, with lowest scores in winter, when the satellite product also suffers weaker statistical significance due to the presence of clouds. The increase in resolution is found to affect the spatial correlation more the Po Valley (+23 %) than in BeNeLux (+5 %). This difference is likely to depend on the very different meteorology of the two hot-spots.

International Journal of Heat and Mass Transfer, May 1, 2002

In the present work, a numerical study of the effect of a hot wavy wall of a laminar natural conv... more In the present work, a numerical study of the effect of a hot wavy wall of a laminar natural convection in an inclined square cavity, differentially heated, was carried out. This problem is solved by using the partial differential equations, which are the vorticity transport, heat transfer and stream function in curvilinear coordinates. The tests were performed for different inclination angles, amplitudes and Rayleigh numbers while the Prandtl number was kept constant. Two geometrical configurations were used namely one and three undulations. The results obtained show that the hot wall undulation affects the flow and the heat transfer rate in the cavity. The mean Nusselt number decreases comparing with the square cavity. The trend of the local heat transfer is wavy. The frequency of the latter is different from the undulated wall frequency.

Microelectronics Reliability, Jun 1, 2015

A Computational Fluid Dynamic (CFD) study based on Reynolds Averaged Navier-Stokes (RANS) approac... more A Computational Fluid Dynamic (CFD) study based on Reynolds Averaged Navier-Stokes (RANS) approach is carried out to predict the mean velocity field and the heat transfer rate of an impinging jet in cross-flow configuration on a heated wall-mounted cube. Targeting an electronic cooling configuration, the aim is to investigate the effect of geometrical modification of the component on the cooling effectiveness. For the same cross flow Reynolds number Re H = 3410, three levels of impinging jets are computed as well as a case without impinging jet that will serve as baseline case for comparison. The results from the RANS computation are compared to experimental data from published scientific literature. The validation shows qualitatively good agreement and almost all flow structures are well reproduced by the computation. In an attempt to optimize the wall heat flux over the cube surface, a new geometry is proposed without sharp corners on the top cube face. Numerical results show that with minor geometrical modification (chamfer), the fluid flow structure around the electronic component is radically transformed and the heat transfer rate can be improved. The highest cooling effectiveness improvement is realize for the highest Reynolds number ratio Re j /Re H = 1.5 and for the chamfer height of 4 mm.

Applied Journal of Environmental Engineering Science, Mar 31, 2018

This work reports three-dimensional simulation results of thermal mixing in rectangular T-junctio... more This work reports three-dimensional simulation results of thermal mixing in rectangular T-junction configuration at high Reynolds number. The validation data are provided by an experimental study done at

Journal of Fundamental and Applied Sciences, 2018

Different passive control methods are discussed in this paper with the purpose of improved the qu... more Different passive control methods are discussed in this paper with the purpose of improved the quality of the air and dispersed the pollution outside the urban canyon road. Numerical investigation model is used in this paper, to examine two methods of passive control within a crossing under building and Low Boundary Wall in center of road for reducing air pollution concentration using Reynolds-averaged Navier-Stokes equations and the k-Epsilon turbulence model as close of the equation system. The results of this investigation show that a low boundary wall located at the central median of the street canyon creates a significant reduction in pedestrian exposure, relative to the same canyon with no wall. The magnitude of the exposure reduction was also found to vary according to the numbers of the crossing under building in the street canyon geometry. The values of the concentration normalized is decreased in the critical region were located in the centerline of the street canyon.

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2014 (ICNAAM-2014), 2015

We report three-dimensional simulation results of thermal mixing in square T-junction configurati... more We report three-dimensional simulation results of thermal mixing in square T-junction configuration at high Reynolds number. The square T-junction configuration with different channel sizes was studied experimentally at the Department of Mechanical Engineering of Mie University, Japan. The T-Junction was selected as a benchmark for thermal mixing in the ERCOFTAC Workshop held in EDF Chatou, France, 2011. RANS, URANS and SAS simulations were performed with CFD code using finite volume method The comparison shows excellent agreement between SAS and the data.

Defect and Diffusion Forum, May 1, 2021

This paper deals with studying numerically two circular turbulent jets impinging on a flat surfac... more This paper deals with studying numerically two circular turbulent jets impinging on a flat surface with a low velocity cross flow by using ANSYS CFX 16.2, with the aim of proving the effect ofReynolds number on the flow demeanor in a vertical circular free turbulent jet with cross flow. Five turbulence models of the RANS (Reynolds Averaged Navier–Stokes) approach were tested and the k -ω SST model was chosen to validate CFD results with the experimental data. Average velocity profiles, velocity and turbulent kinetic energy contours and streamlines are presented for four case configurations. In the first three cases, the following parameters have been varied: Reynolds number at the level of the two jets ( ), wind velocity at the level of the cross-flow ( ), and the distance between the two jets (S = 45mm, 90mm and 135mm). In the last case, a new configuration of the phenomenon not yet studied so far was treated, where horizontal cross-flows were introduced from both sides in order to simulate gusts of wind disrupting a VSTOL aircraft which tries to operate close to the ground. This case was carried out for Reynolds number based on the crossflow of 4 104, 10 104 and 20 104 .The numerical results obtained show that the deflection of the jets is minimal when the Reynolds number at the level of the jets is greater than that of the cross-flow. The increase of Reynolds number at the level of the cross-flow reveals a significant deviation of the two jets with an intensity which always remains less for the second jet. As for the space parameter between the two jets, it turns out that the fact of further spacing the two jets makes the first jet even more vulnerable and leads to a greater deflection. Finally, the simulation of the wind gusts from the front and the back caused a zone of turbulence which resulted from a form of "interlacing" of the two jets under the effect of the transverse current imposed by the two sides.

ABSTRACT Les performances du modèle de turbulence de second ordre proposé par [1] et noté SSG-RSM... more ABSTRACT Les performances du modèle de turbulence de second ordre proposé par [1] et noté SSG-RSM Model sont testées pour modéliser le phénomène du refroidissement par film appliqué sur le bord d’attaque d’une aube symétrique de turbine à gaz. Pour compléter l’étude le même calcul est réalisé par l’utilisation du modèle standard k-ε et les résultats des deux simulations sont comparés aux mesures expérimentales disponibles dans la littérature. La présente étude est réalisée à l’aide du code de calcul ANSYS CFX 5.7.1. Le cas étudié est une aube de turbine à gaz de forme symétrique munie de deux rangées de trous d’injection cylindrique positionnée de part et d’autre du bord d’attaque. Dans la présente étude, trois taux d’injection ont été testés et les résultats obtenus sous forme de contours de l’efficacité de refroidissement sur la surface de l’aube et l’efficacité latérale moyenne ont été comparés avec succès aux résultats expérimentaux.

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2014 (ICNAAM-2014), 2015

This paper investigates the effect of the pulsating film cooling at the leading edge of a symmetr... more This paper investigates the effect of the pulsating film cooling at the leading edge of a symmetrical turbine blade model. Numerical finite volume method is used to resolve the Unsteady Reynolds Averaged Navier Stokes Equations coupled at turbulence model. Detailed numerical film cooling effectiveness have been made for both steady and pulsating flows. The test case blade model is symmetric and has one injection row of discrete cylindrical holes on each side near the leading edge. Jet pulsing frequencies of 5 Hz, 10 Hz, and 20 Hz have been studied. The computational domain is discretized using a highly refined multi-bloc structured grid including the plenum area. The turbulence field is resolved by use of the SST turbulence Model. The numerical simulations are conducted for three different blowing ratios of 0.3, 0.5, and 0.7; film cooling effectiveness contours on the blade surface and lateral averaged adiabatic film cooling effectiveness are presented and the continuous jet results compared with availabl...

Computational Thermal Sciences, 2018

Dans cette étude, une investigation numérique est réalisée pour évaluer l'efficacité de la techni... more Dans cette étude, une investigation numérique est réalisée pour évaluer l'efficacité de la technique des trous latéraux (Anti-vortex) du refroidissement par film. Ce concept d'anti-vortex est développé et étudié au centre de recherche de la NASA Glenn. Il est conçu pour atténuer les effets contre-rotatifs qui sont la cause de la réduction de l'efficacité de refroidissement par film au taux d'injections élevés. Cette conception d'antivortex consiste en deux trous secondaires de refroidissement à côté du trou principal. Ces deux trous sont légèrement en aval du point central du trou principal de telle façon que l'injection secondaire détruit le deux vortex contra rotatif (Kidney Vorticies). L'avantage de cette conception est la réduction des vorticités indésirables et l'amélioration de l'efficacité du refroidissement par film. Cette investigation d'anti-vortex est réalisée par un code commercial résolvant les équations de Navier-Stokes et l'équation de l'énergie moyennant la méthode des volumes finis (ANSYS CFX 12.0). Le domaine de calcul est discrétisé en utilisant un maillage hexa incluant la partie refroidie, les trous d'injection et la boite d'alimentation. La turbulence est résolue avec le modèle de premier ordre SST. Deux configurations géométriques combinées avec des taux d'injections élevés et des rapports de masse volumiques variables sont considérés. Il a été trouvé que les trous latéraux améliorent la performance du refroidissement à travers tous le domaine de calcul. Les résultats numériques des trous équipés de la conception d'anti-vortex sont comparés avec le cas de base où l'injection se fait à travers un seul trou rond Sinha et al. (1991). Les résultats numériques montrent aussi une amélioration prometteuse dans tous les aspects thermo-fluide.

Springer eBooks, 2007

In this contribution we intend to present a summary of a joint European project in frame of MEDA-... more In this contribution we intend to present a summary of a joint European project in frame of MEDA-TEMPUS program. The main aim of this project is to set up in Algeria (USTO University) a Master Degree that will focus on Air Pollutant Dispersion Modelling. To the best knowledge of the author, this is the first time that this level of

Journal of Applied Sciences, Jul 15, 2005

Computational Thermal Sciences, 2016