IJE_Vol 05 N 01

Permanent URI for this collectionhttps://archives.univ-eloued.dz/handle/123456789/22770

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Effect of the fluidic injection on the flow of a converging-diverging conical nozzle
(جامعة الوادي - university of el oued, 2020-06-21) Benderradji, Razik; Gouidmi, Hamza; Beghidja, Abdelhadi Abdelhadi
The flow in an Over-Expanded Nozzle is subjected to shock waves leading to the unsteady separation of the boundary layer. Free detachment may be followed by a restricted detachment. During the expansion regime in propellant nozzles, several physical phenomena are encountered: supersonic jet, jet separation, adverse pressure gradient, shock wave, turbulent boundary layer, highly compressible mixture layer, return flow, large scale turbulence. These very complex phenomena can considerably affect the performance of the nozzle.The numerical investigation was performed by the CFD-FASTRAN search code, using the k-w SST model as the turbulence model. The calculation is performed by solving the Navier-Stokes equations of twodimensional compressible turbulent flow. It is based on the study of the fluidic vectorization phenomenon of the thrust of a double-injection convergent-divergent supersonic conical nozzle. The study is based on the effect of the ratio of NPR pressures with SPR = 1 on the overall structure of shock waves. The calculation is highlighting the behavior of a flow that has not neglected. In particular, the appearance of the separation zone formed by the fluid jet and the deflection of the main jet cause separation shocks
Enhancing of CH3NH3SnI3 based solar cell efficiency by ETL engineering
(جامعة الوادي - university of el oued, 2020-06-12) Hima, Abdelkader; Khechekhouche, ,Abderrahmane; Kemerchou, Imad
Solar cells based on organic-inorganic perovskites (PVK) are the subject of several researches in laboratories around the world. One of the most promising hybrid perovskite is the methylammonium lead tri-iodide MAPbI3 that is suitable for sun light harvesting. But the MAPbI3 is a toxic material, so in this paper is proposed another nature friendly candidate which is the methylammonium tin tri-iodide MASnI3. The proposed material is inserted into an n-i-p heterojunction solar cell which structure is electron transport layer (ETL)/PVK/hole transport layer (HTL). The used HTL is the PEDOT: PSS in combination with one of two ETLs which are the PCBM and the IGZO. Simulation efforts using 1D SCAPS was carried. It is found that IGZO ETL based solar cell yields a higher power conversion efficiency (PCE) compared with PCBM ETL based solar cell in the same thickness
Experimental Investigation of the Effects of Preheating on Still Productivity
(جامعة الوادي - university of el oued, 2020-06-19) Cherraye, Ridha; Bachir, Bouchekima
Single basin solar still (SBSS) has low productivity in this experimental research, some techniques have been employed to solve this problem, these techniques consist of using a flat plate collector. The main aim of this research was to make efficient use of the flat plate collector (FPC) to increase solar still productivity, and it works as a hybrid device. The model solar water heater for the flat plat collector (FPC) was coupled with a solar still, and the tests were repeated in 3 to 5 winter days, and the results were measured in the same way for each day. The results revealed that the productivity of the still increased 87 % when coupled with one, and decreased 20 % and 50 % when coupled with two and three flat plate collectors in southern Algeria, respectively
Extraction of the electrical parameters of the Au/InSb/InP Schottky diode in the temperature range (300 K- 425 K)
(جامعة الوادي - university of el oued, 2020-06-20) Sadoun, Ali; Kemerchou, Imad
In this work, we have presented a theoretical study of Au/InSb/InP Schottky diode based on current-voltage (I-V) measurement in the temperature range ( 300 K- 425 K). Electrical parameters of Au/InSb/InP such as barrier height (Φb), ideality factor and series resistance have been calculated by employing the conventional (I-V), Norde, Cheung and Chattopadhyay methods. Measurements show that the Schottky barrier height (SBH), ideality factor and series resistance, RS for Au/InSb/InP Schottky diode in the temperature range (300 K–425 K) are 0.602-0.69eV, 1.683-1.234 and 84.54-18.95 (Ω), respectively. These parameters were extracted using Atlas- Silvaco-Tcad logical
Numerical study of a new earth-air heat exchanger configuration designed for Sahara climates
(جامعة الوادي - university of el oued, 2020-06-19) Hadjadj, Abdessamia; Attia, Abbes; Khechekhouche, Abderrahmane; Naili, Nabiha; Bendjenid, Bachir
Thermal performance for cooling and heating in the building can be achieved by the novel shape of the earth–air heat exchanger (EAHE). In a heavily populated area such as City, Due to the limited ground space. EAHE systems are rarely used, for most residential andcommercial utilization.This paper presents a numerical investigation of the thermal performance of a spiral-shaped configuration Spiral Earth to Air Heat Exchanger SEAHE intended for the summer cooling inhot and arid regions of Algeria. A parametric analysis of the SEAHE has been performed toinvestigate the effect of diameter, depth, pipe length and of airflow rate on the outlet air in theexchanger. Results show that the specific heat exchange is used to cool in an arid zone (south-east of Algeria). When the ambient temperature varies between 40°C and 45 °C, the coolingtemperature varies between 25°C and 29 °C. Temperature difference inlet and outlet airexchanger 18°C, these values are quite acceptable with for cooling the building.
Study of a solar air conditioning system with ejector
(جامعة الوادي - university of el oued, 2020-04-10) Ghodbane, ,MokhtarMokhtar; Boumeddane, Boussad; Khechekhouche, Abderrahmane; Benmenine, Djamel
Air conditioning is one of the indispensable conditions of well-being in human life, so the face of this research to provide this basic necessity in remote areas and in desert places far from power grids. To achieve this goal, solar air conditioning has been adopted, where the compressor was replaced by an ejector, a parabolic trough solar collector coupled with a thermal generator and a small pump; this means that the solar air conditioner does not need a huge amount of electrical energy to operate. This paper is studding the optical and thermal efficiency of the solar collector used as a solar thermal generator, refrigeration subsystem performance (COPejc) and system thermal ratio of the studied air conditioner, where the cooling load is estimated at 18 kW. This work has allowed to acquire very important knowledge about R718 ejector solar air conditioners. Bouzaréah was chosen as the region to conduct this numerical study on June 11th, 2018. Regarding performance of the studied air conditioning subsystem (COPejc) is 0.6235. As for the PTC solar reflector subsystem, its mean optical performance is 75.74 % and its mean thermal performance is 65.01 %. Regarding the overall performance of the studied air conditioner, its mean value is 0.407
Studying sediment transport dynamics by using the Smart sphere
(جامعة الوادي - university of el oued, 2020-06-12) Alhusban, ZaidZaid; Valyrakis, Manousos
A new method is introduced by using high precision accelerometer and gyroscope micro-electromechanical sensors (MEMS), which can record Lagrangian observations of sediments and shed light into the dynamics of sediment transport processes at above threshold conditions. The sensor can be used under a range of well-controlled flow conditions and can record measurements at high frequency (200 Hz), which can be used at the field. The smart sphere performance was evaluated by comparing its rotation and acceleration readings from the sensors to the video recordings of both top and underwater high-speed camera for a range of flow rates and sphere densities. Furthermore, an initial attempt to compare the smart-sphere’s velocity is achieved, by transforming the particle’s velocity from the Lagrangian frame of reference, obtained from the inertial sensor, to its velocity at the Eularian frame, obtained from the top camera.

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