In this paper, a thermal-economic analysis of a modular solar still was investigated. For that, a modular solar still was designed. The collector area and the condensation chamber area effect on the productivity and distilled water cost were examined. Simulations were performed according to meteorological data of Algiers (Algeria) using Liu Jordan method. Results show that the surface area of collector increase increases the evaporated water and distilled water production at the same time. The average annual production passed from 482.35 L for 2 m 2 of solar collector to 2083.65 L for 10 m 2 of solar collector. On the other side, increasing surface of solar collector decreases the cost of distilled water. The cost of liter of distilled water varies between 0.12 and 0.04$ for 2 and 10 m 2 of collector, respectively. Also, when the condensation chamber area increases, the amount of the distillate water produced decreases.

In this article, the validity of a numerical simulation of a basin solar still coupled with a condensation chamber was analyzed, before being cooled through a cooling water system. The system contained a serpentine pipe combined with a rectangular sheet of galvanized steel. The model was validated by comparing calculated and then experimental results mentioned in previous research for a typical day in the month of June 2013, the comparison of results showed a good agreement between the experimental and numerical tests. The model was developed to evaluate the performance of the system with optimum mass flow and compared throughout the typical day of each month of the year with that of a solar still without cooling. The model was investigated numerically according to meteorological data of the Algerian city, Khemis Miliana using the model of Capderou. The equations are modeled by the finite difference method, the Gauss–Seidel iterative method was used to solve the resulting algebraic equation. The highest productivity of the year was 6.7 Kg/m2 during the typical day of august with 60% higher productivity than the still without cooling. It was observed that the productivity of the solar still was sensitive to the flow mass of cooling water. Both the condenser chamber volume and the area from the opening of the evaporator to the condenser chamber have a significant effect on distillate production of the system. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019

The wake and the lack of existing velocity behind the wind turbine affect the energy production and the mechanical integrity of wind turbines downstream in the wind farms. This paper presents an investigation of the unsteady flow around a wind turbine under yawed condition. The simulations and experimental measures are made for the yaw angle rotor 30° and 0°. The wind velocity is 9.3 m/s and the rotation velocity rotor of the wind turbine in 1300, 1500 and 1800 rpm. The wind turbine rotor which is modeled is of a commercial wind turbine i.e. Rutland 503. The approach Improved Delayed Detached Eddy Simulation (IDDES) based on the SST turbulence model is used in the modeling of the flow. The solutions are obtained by using the solver which uses finite volume method. The particle image velocimetry (PIV) method is used in wind tunnel measurements in the experimental laboratory of the ENSAM Paris-Tech. The yawed downstream wake of the rotor is compared with that obtained by the experimental measurements. The results illustrate perfectly the development of the near and far wake of the rotor operation. It is observed that the upstream wind turbine yawed will have a positive impact on the power of the downstream turbine due the distance reduction of the downstream wake of the wind turbine. However the power losses are important for yawed wind turbine when compared with the wind turbine without yaw. The improved understanding of the unsteady environmental of the Horizontal Axis wind Turbine allows optimizing wind turbine structures and the number of wind turbines in wind farms.

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In this paper, an experimental analysis of a solar system composed of a basin solar still with an additional condensation chamber was investigated. For this, a prototype was designed and constructed. The condensation chamber was cooled by a forced circulation of cold water. A solar pump powered by a solar panel ensures the circulation of cooling water. Experiments were performed under meteorological conditions of Khemis Miliana (Algeria) for several summer days. Solar radiation, the cooling flow rate, ambient temperature, and temperatures at different points of the condensation chamber and the still were measured. The effect of the cooling flow rate on the performances of the still was investigated. The amount of distillate water and the efficiency of the system increase to 43% and 26%, respectively, compared to those of the system not involving the cooling process. The results show the existence of a limit beyond which any further increase in the cooling water flow rate will produce opposite effects.