The Investigation of the Mixed Convection from a Confined Rotating Circular Cylinder

In this paper, a numerical study on the two-dimensional laminar mixed convective flow and heat transfer from an rotating circular horizontal and isothermal cylinder confined in a horizontal channel. The blockage ratio and the Prandtl number are fixed at 0.05 and 0.7 respectively. The continuity, momentum and energy equations are solved via the finite-volume method. Our results are in very good agreement with those resulting from preceding studies to Ri=0 and a=0, which makes it possible to validate on important extension of present work. The mixed convective flow and heat transfer is simulated by the Reynolds number is studied in the range 1 <Re <40, the Richardson number (Ri) demonstrating the influence of thermal buoyancy ranges from 0 to 1 and for rotational rate from α=0 to α=4. Major emphasis is given to the effect of rotating a circular cylinder on the mixed convection and also on the measurements of the local and average Nusselt numbers are also obtained. Furthermore, the representative streamlines and isotherm patterns are presented and discussed

Road Transportation Industry Facing the Energy and Climate Challenges

On a worldwide scale, vehicles, which constitute the transportation sector, play a major role in supporting the other productive sectors. In addition, the automobiles help promoting the living standards of human beings by satisfying the needs of most people in their daily activities. Nowadays, for the traction or repulsion of vehicles, the overwhelming majority of these automobiles are equipped with internal combustion engines (ICE); however, the automotive industry is moving steadily toward the adoption of new technologies because of the rapid depletion of fossil fuels and climate challenges caused by the transport sector, which accounts for the 27% of global energy consumption and for 33.7% of pollutant emissions and green house gas (GHG). For road transportation sector, the fuel-cell electric vehicle is one of the promising solutions advocated by car manufacturers and research entities to replace gradually conventional vehicles

Electric Automobile Ni-MH Battery Investigation in Diverse Situations

AbstractThe electronic differential system ensures the robust control of the vehicle comportment on the road. This paper focuses Ni-MH Battery controlled by Buck Boost DC-DC converter power supply for EV. Sliding mode control based on space vector modulation (SVM-SMC) is proposed to achieve the tow rear driving wheel control. The performances of the proposed strategy controller give a satisfactory simulation results. The proposed control law increases the utility EV autonomous under several speed variations. Moreover, the future industrial's vehicle must take into considerations the battery material choice into design steps. The battery material model choice is a crucial item, and thanks to an increasing emphasis on vehicle range and performance, the Ni-MH battery could become a viable candidate that's our proposal battery model in the present work, in this way the present paper show a novel strategy of electric automobile (EA) power electronics studies when the current battery take into account the impact of the sliding mode control based onspace vector machine technique in the several speed variations using the primitive battery SOC of 60% state

Etude du comportement aéraulique des maisons à ouverture zénithale

En été et dans un climat chaud et sec ; comme celui des villes du sud algérien, c’est quasiment insupportable de rester dans un bâtiment sans utilisation de climatisation, ce qui a été montré par des études expérimentales et numériques. Dans les régions sahariennes des pays maghrébin, le climat est le plus souvent chaud et aride, avec un hiver très court froid et sec. Les modes de constructions traditionnels réalisent des conditions de conforts acceptable l’essentiel de l’année, durant les périodes chaudes ou très chaudes par une architecture climatique exemplaire assurant une climatisation naturelle satisfaisante et des modes de chauffage simples permettant de traverser la période froide. La maison à patio couvert, est un type de maison traditionnel très répondu dans le Ksar de Kenadsa. Dans ce travail, nous tentons par une simulation numérique, à l’aide du logiciel de simulation thermique TRNSYS couplé au logiciel aéraulique COMIS, d’examiner le comportement de aéraulique de ce type de maison ainsi que son influence sur la qualité de l’air et sur le confort thermique de dans un climat désertiques. Les résultats de la simulation ont montré l’insuffisance de l’ouverture horizontale seule de dimension de 1X1m² d’assurer une bonne qualité de l’air

Moisture sorption isotherms and thermodynamic properties of Asteriscus graveolens leaves

Asteriscus graveolens is a medicinal and aromatic plant which has been used to treat several diseases.Moisture equilibrium data of the plant leaves were determined by using the gravimetric static method at 30°C, 40°C, and 50°C for water activity

Influence of Aspect Ratio on Natural Convection in a Partially Porous Enclosure

The objective of this research is the study the influence of aspect ratio A1 of fluid portion compared to the height of cavity, on the natural convection in a partially porous enclosure. A cylindrical heat source maintained at a uniform temperature is introduced into porous portion. The equations which describe the thermal transfer and the hydrodynamic flow are described by the Navier-Stokes equations modified by using the extension of Darcy-Brinkman and the energy equation. The results obtained are in the form of isotherm`s distribution, stream`s functions, the local and the average Nusselt numbers and the pressure. Correlations between these parameters and the aspect ratio are considered

Impact of the Air-Conditioning System on the Power Consumption of an Electric Vehicle Powered by Lithium-Ion Battery

The car occupies the daily universe of our society; however, noise pollution, global warming gas emissions, and increased fuel consumption are constantly increasing. The electric vehicle is one of the recommended solutions by the raison of its zero emission. Heating and air-conditioning (HVAC) system is a part of the power system of the vehicle when the purpose is to provide complete thermal comfort for its occupants, however it requires far more energy than any other car accessory. Electric vehicles have a lowenergy storage capacity, and HVAC may consume a substantial amount of the total energy stored, considerably reducing the vehicle range, which is one of the most important parameters for EV acceptability. The basic goal of this paper is to simulate the airconditioning system impact on the power energy source of an electric vehicle powered by a lithium-ion battery

Effect of ultrasound on henna leaves drying and extraction of lawsone: Experimental and modeling study

[EN] The effect of drying temperature and the application of ultrasound on drying kinetics of Lawsonia inermis (henna) leaves and the extraction of lawsone from the dried samples was addressed. Indeed, henna leaves were dried with and without the application of ultrasound (21.7 kHz, 30.8 kW/m3) at 40, 50 and 60 C with a constant air velocity (1 m/s). As expected, both the increase of temperature and the application of ultrasound decreased the drying time and increased the rate of extraction of the lawsone. The values of the effective diffusion coefficients obtained were used to quantify this influence showing the value increases with higher drying temperature and the application of ultrasound. Moreover, the influence of temperature was quantified by the estimation of the activation energy from an Arrhenius-type equation (46.25 kJ/mol in the case of drying without ultrasound application and 44.06 kJ/mol in the case of ultrasonically-assisted drying). Regarding the influence of studied variables on lawsone extraction yield, the higher is the temperature, the lower is the yield, probably linked with lawsone degradation reaction due to thermal treatment. On the contrary, the application of ultrasound improved the extraction yield mainly at the lower drying temperature tested of 40 C.This research was funded by Science and Innovation Ministry of Spain, grant number PID2019-106148RRC42.Bennaceur, S.; Berreghioua, A.; Bennamoun, L.; Mulet Pons, A.; Draoui, B.; Abid, M.; Carcel, JA. (2021). Effect of ultrasound on henna leaves drying and extraction of lawsone: Experimental and modeling study. Energies. 14(5):1-11. https://doi.org/10.3390/en14051329S11114

Effect of ultrasound on drying kinetics of El Henna leaves (Lawsonia inermis)

[EN] In this work the influence of some process variable on drying rate of henna leaves was studied. For this reason, henna leaves were dried (1 m/s) with and without ultrasound application at three temperatures, 40, 50 and 60 °C. As can be expected, the higher the temperature the faster the drying process. Ultrasound application increase drying rate at every temperature tested. Drying kinetics were modeled by using different experimental models. Weibull model provided the best fit for henna leaves drying kinetics.The authors acknowledge the financial support of INIA-ERDF throughout the project RTA2015-00060-C04-02Bennaceur, S.; Bennamoun, L.; Mulet Pons, A.; Draoui, B.; Cárcel Carrión, JA. (2018). Effect of ultrasound on drying kinetics of El Henna leaves (Lawsonia inermis). En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 887-894. https://doi.org/10.4995/IDS2018.2018.7530OCS88789