Browsing by Author "Tlili, Iskander"

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Citation - WoS: 32
Citation - Scopus: 32
Flat sheet direct contact membrane distillation study to decrease the energy demand for solar desalination purposes
(Elsevier, 2022) Tlili, Iskander; Baleanu, Dumitru; Sajadi, S. Mohammad; Baleanu, Dumitru; Ghaemi, Ferial; 56389
One of the most important feature of any desalination technology is energy consumption of producing fresh water specially when its energy source is solar energy. To improve this, study of various input parameters and determination of their effects on energy consumption would be essential. In this paper, a one-dimensional model is used to investigate the effects of different operational and geometrical parameters on energy consumption of flat sheet direct contact membrane distillation (DCMD) for solar desalination purposes. It is assumed that the energy consumption of DCMD includes of electrical to drive electro pumps and thermal energy. In this regard, variation of each parameter is studied at different inlet bulk flow temperatures difference (TD). Results show that specific energy consumption (EC) of DCMD is improved by increasing inlet bulk flow temperature difference regardless of any parameter variations. Nevertheless, increasing of Inlet mass flow rate and decreasing inlet salinity are also enhanced specific energy consumption. For geometrical parameters, increasing length, width and channel height increase energy consumption while increasing membrane porosity and thickness do the opposite. It is also observed that the electrical energy incorporates a very small portion of whole energy consumption in most cases but when small channel width or height is selected it becomes significant. Since electrical energy is more expensive than thermal energy, careful channel geometry design must be done.
Citation - WoS: 33
Citation - Scopus: 34
Numerical and experimental analysis of temperature distribution and melt flow in fiber laser welding of Inconel 625
(Springer London Ltd, 2022) Tlili, Iskander; Baleanu, Dumitru; Baleanu, Dumitru; Sajadi, S. Mohammad; Ghaemi, Ferial; Fagiry, Moram A.; 56389
In these days, laser is a useful and valuable tool. Low input heat, speed, accuracy, and high controllability of laser welding have led to widespread use in various industries. Nickel-based superalloys are creep-resistant materials used in high-temperature conditions. Also, these alloys have high strength, fatigue, and suitable corrosion resistance. Inconel 625 is a material that is strengthened by a complex deposition mechanism. Therefore, the parameters related to laser welding affect the microstructure and mechanical properties. Therefore, in this study, the effect of fiber laser welding parameters on temperature distribution, weld bead dimensions, melt flow velocity, and microstructure was investigated by finite volume and experimental methods. In order to detect the temperature history during continuous laser welding, two thermocouples were considered at a distance of 2 mm from the welding line. The heat energy from the laser beam was modeled as surface and volumetric heat flux. The results of numerical simulation showed that Marangoni stress and buoyancy force are the most important factors in the formation of the flow of liquid metal. Enhancing the laser power to 400 W led to the expansion of the width of the molten pool by 1.44 mm, which was in good agreement with the experimental results. Experimental results also showed that increasing the temperature from 500 degrees C around the molten pond leads to the formation of a coarse-grained austenitic structure.
Citation - WoS: 5
Citation - Scopus: 9
Numerical study of heat transfer in a microchannel equipped with the semicircular ribs influenced by slip condition: effects of various slip coefficient and Hartmann number
(Springer Heidelberg, 2022) He, Xinlin; Baleanu, Dumitru; Alderremy, A. A.; Aly, Shaban; Tlili, Iskander; Ghaemi, Ferial; Baleanu, Dumitru; 56389
In the present work, a microchannel that benefits from the simultaneous effect of slip condition and semicircular ribs was studied to boost heat transfer. A numerical method was utilized to examine the thermal and hydraulic behavior. The results reveal that the velocity is not zero since the slip condition exists in the microchannel. Furthermore, the velocity near the wall has a dramatic value when the slip length increases. Although the heat transfer is not remarkable by semicircular ribs, the magnetic field plays a vital role in boosting the heat transfer as a result of the declining thermal boundary layer. The effect of magnetic field on the heat transfer on the low Re number is not like the higher one which means as the Reynolds number (Re) varies from 10 to 90, the heat transfer goes up from 1.12 to 2.63. Furthermore, at Re = 90, a 255% enhancement is seen in the microchannel by affecting magnetic field at Hartmann number = 15. The results of slip condition claim that slip condition is introduced as the third most effective factor in rising and improving the efficiency of the microchannel. There is a 16.23% improvement in heat transfer by using slip condition in the microchannel. More importantly, the figure for heat transfer is enhanced by increasing the radius of ribs.