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In this study, performance of gas liquid cylindrical cyclone separators and the effect of changing geometrical parameters of cyclone separators entrance is investigated. The cyclone is simulated with computational fluid dynamic methods. After choosing a suitable mesh grid for the cyclone and checking grid independency, the effect of changing entrance geometry on gas carry under and liquid carry over is investigated. Geometrical parameters, especially inlet geometrical parameters have great effect on optimizing cyclone separators performance. RSM model is used for turbulence simulation of the flow and two phase flow is simulated using Eulerian- Eulerian approach. In this simulation, inlet cross section, inlet angle and inlet height relative to the cyclone bottom part are optimized. Results show that GCU decreases with decreasing nozzle’s inlet angle. An optimum point for GCU was given with changing inlet altitude relative to the bottom of the cyclone and inlet nozzle’s width. An optimum point for LCO was obtained with changing inlet altitude and inlet nozzle width. Increasing inlet angle causes a decrease in LCO. In optimum model, gas carry under decreases significantly and liquid carry over is eliminated.

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In this research, the Asphaltene particles deposition is modeled using species transport equations. It is assumed that the deposition phenomenon consists of two steps: transport of Asphaltene particles toward the wall and attachment of them to the wall. Due to the small size of Asphaltene particles, their motion is simulated using species transport equation. Transport of Asphaltene particles is modeled by turbulent and Brownian diffusion and attachment mechanism is modeled employing first order chemical reaction. Effects of surface temperature and velocity is considered in the model. Finally the effects of velocity, surface temperature and Asphaltene concentration is investigated and compared with experimental data. The simulation results are agreed well with experimental data and the maximum error of is about 20 percentage. Also in addition of deposition rate, transport and attachment rate are investigated. The results indicate that Asphaltene attachment is more important than transport of Asphaltene, so accurate modelling of attachment has significant effect on prediction of Asphaltene deposition rate.

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The use of interfacial solar evaporation systems can be a suitable method to deal with the problem of fresh water shortage in the world. Interfacial solar evaporation systems can be widely used in the production of fresh water due to the use of solar energy as a without any costs energy and no environmental effects and also free from high pressure operations and no need for moving parts. But in order to use interfacial solar evaporation system for practical application, evaporation rate with high efficiency is required. In this research, the performance of a hollow cylindrical interfacial solar evaporation system with nature inspired water distribution to steam generation has been evaluated by numerical simulation. This system can absorb solar radiation more effectively. In this study, in order to accurately investigate the performance of the interfacial solar evaporation systems, steam generation and system efficiency were evaluated by changing environmental factors. Also, in order to investigate the performance of the interfacial solar evaporation systems under different angles of solar radiation in real world conditions, the rate of steam generation in two days of summer solstice and winter solstice in Tehran city has been evaluated. The results of this research show that the cylindrical interfacial solar evaporation system can have a steam generation rate of 3.09 kg/m².h and 9.09 kg/m².h in winter solstice and summer solstice respectively in Tehran city with wind flow

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Nowadays, fresh water scarcity is one of the major concerns of the global community. To tackle the freshwater scarcity situation, several solutions have been suggested, including the extraction of water from fog-laden flow. Fog harvesting is known as a sustainable and effective approach to supplying freshwater. Various types of fog collecting elements (FCEs) have been implemented in studies to collect water from fog-laden flow. Woven meshes with square-shaped holes are among the most frequently employed FCEs in studies. One of the major drawbacks of these types of FCEs is their low water collection efficiency, particularly at low wind velocities. In this study, two alternative mesh hole geometries, triangular and hexagonal, were proposed to enhance the collection efficiency and compared with an equivalent square mesh in terms of the shading coefficient (SC). The evaluations were conducted experimentally using an experimental setup capable of mimicking atmospheric fog-laden flow at two different air velocities. The results indicate that the water harvesting rate is highly affected by mesh hole geometry. Using triangular and hexagonal meshes, compared to square mesh, can improve the water collection rate by up to 12.6% and 29%, respectively