Yazar "Abdullaeva, Barno" seçeneğine göre listele

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    EXPERIMENTAL INVESTIGATION OF COOLING PERFORMANCE IN ELECTRONIC INSTRUMENTS
    (Vinca Inst Nuclear Sci, 2023) Bensafi, Mohammed; Kaid, Noureddine; Shnawa, Ammar H.; Alsharari, Abdulrhman M.; Mohsen, Karrar S.; Akgul, Ali; Abdullaeva, Barno
    This study explores the principle of producing cold through heat absorption at a temperature lower than ambient temperature, which requires the use of an endothermic mechanism. Specifically, the study focuses on evaluating multiple thermoelectric coolers using aluminum water heat exchangers as a means of validating a proposed correlation through a series of experiments. The system utilizes water as a coolant and a thermoelectric cooler coupled with a heatsink to cool it. The cooling power of the system is controlled by adjusting the temperatures of the hot and cold heatsinks and the coolant flow through the heat exchanger based on governing equations. In addition to assessing the cold-side temperature, the research also investigates the system COP of the thermoelectric system. The results indicate that a thermoelectric cooler with a lower thermal resistance is more effective at cooling and can achieve a lower cold-side temperature. Conversely, a cold-side heatsink with a higher thermal resistance provides lower cooling power. Two experiments were conducted to acquire comprehensive data on the thermoelectric devices, and the obtained results and experience were used to categorize the utilization of the Peltier model. The first experiment achieved an 84% success rate, while the second experiment achieved a rate of around 97-95%, highlighting the potential for further experimentation with alternative configurations.
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    IMPROVEMENT OF THE PERFORMANCE OF SMALL-SIZED CAVITATING VENTURIS BY INSERTING OBSTACLES
    (Vinca Inst Nuclear Sci, 2023) Rostane, Brahim; Aliane, Khaled; Brayyich, Mohammed; Zearah, Sajad A.; Akgul, Ali; Abdullaeva, Barno; Menni, Younes
    Cavitating Venturis are simple apparatus used as a flow meter over a broad range of mass-flow rates. The main objective of this work is to introduce obstacles in small-sized cavitating Venturis in order to increase their capacity by raising the critical pressure, i.e. widens the phase of the cavitating mode. Four configurations have been tested depending on the location of these obstacles. This study focused on investigating the numerical performance of cavitating Venturis with different downstream pressures by employing the k-. SST turbulence model and the Rayleigh-Plesset equation for modeling cavitation. The governing equations were solved using the finite volume method, employing the Rhie and Chow pressure-velocity coupling scheme. The results showed the void fraction and streamlines contours obtained on the symmetry plane. The mass-flow ratio was presented for all configurations and different pressure ratios. The study showed that the cavitating Venturis equipped with obstacles extend the phase of choked mode from 10.71% to 21.42% and that the best configuration correspond to the case where the obstacles are placed in the converging section.
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    NUMERICAL STUDY ON A NATURAL GAS-FUELED ENGINE UNDER LOW TEMPERATURE COMBUSTION MODE
    (Vinca Inst Nuclear Sci, 2023) Kezrane, Cheikh; Naima, Khatir; Alsharari, Abdulrhman M.; Al-Hameed, Mazin Riyadh; Zearah, Sajad A.; Akgul, Ali; Abdullaeva, Barno
    Natural gas, which is also referred to as eco-friendly fuel, is being seen as a potential solution to challenge the decline of crude oil resources and the deteriorating air quality in urban areas. This fuel has been verified to emit less CO, HC, and PM compared to other fuels. A potential approach to reducing NOx and soot emissions while also achieving low fuel consumption is the low temperature combustion process. In this study, internal combustion engines were simulated under various conditions. The objective was to investigate the effect of different operating variables on the low temperature combustion mode. To begin with, a natural gas powered engine was modeled using complex chemical kinetics software. The outcomes of the simulation were then compared to experimental data, demonstrating a high level of agreement. Subsequently, the impacts of key variables, including the air-fuel ratio, compression ratio, and engine speed, were analyzed using a cycle simulation code. Increasing the compression ratio improves engine performance, and the specific fuel consumption decreases. However, it leads to a significant increase in NOx emissions until a certain value. Thereafter, it changes the trend. Engine speed indirectly affects performance by increasing fuel consumption and changing ignition timing. A leaner air fuel ration may be used to produce more power and keep the temperature of combustion below a certain value (low-temperature combustion), ensuring low NOx emissions.