فهرست مطالب a. e. kabeel

In this investigation, Hemispherical Solar Still (HSS) with Micro/Nano-particles of Copper Oxide (CuO) with various proportions (1, 2, and 3‰) were carried out. Three Solar Stills (SS) have been constructed and experimented such as (i) HSS, (ii) Modified HSS (MHSS) that has micro-particles of CuO (MHSS – 1, 2, and 3‰ M-P of CuO) and (iii) MHSS that has Nano-particles of CuO (MHSS – 1, 2 and 3‰ N-P of CuO). From the experimental results by adding N-P of CuO at proportions of 1‰, 2‰, and 3‰ in the HSS, the yield of 5.28, 5.92, and 6.75 Kg/m2/day has been noticed. On the other hand, when using the M-P of CuO, the MHSS yield is equal to 4.38, 4.82, and 5.43 kg/m2/day for proportions equal to 1, 2, and 3‰, individually. However the highest yield of the HSS was 2.98 Kg/m2/day. Additionally, the diurnal rise in yield of 77.18, 98.65, and 126.51% are obtained when using the N-P of CuO at the proportions of 1, 2, and 3‰, respectively, as related to HSS. By utilizing M-P of CuO, the diurnal increase in yield reaches only 46.98, 61.74, and 82.21% for the proportions of 1‰, 2‰, and 3‰, respectively as connected to the HSS.

The study focuses on heat transfer performance and flow structure associated with swirling jet on a flat target surface. The analysis is carried out with helicoid inserts of swirl number S = 1.3 by varying the number of vanes with Reynolds number between 11200 and 35600. The comparison of swirling jet with circular jet is carried out on its heat transfer performance. The heat transfer and flow structure are visualized using thermo-chromic liquid crystal sheet and oil film technique respectively. The numerical simulation is also performed at Re = 24700 for H/D distance between 1 and 4 using computational fluid dynamics. The heat transfer results reveal that the presence of axial recirculation zone at Re = 29800 and 35600 for the triple helicoid affects the uniformity of heat transfer distribution at 0 < X/D < 1.5 at H/D = 3. The axial component of velocity with respect to swirling jet is less than zero in the stagnation area and it increases at 0.57 < r/D < 0.97 for single vane and 0.63 < r/D < 0.97 for double and triple vanes. While the steep increase in tangential velocity of the triple vane jet is apparent at 0 < r/D < 0.5 at H/D = 2 and 3, the maximum value of point radially shifts inward towards the jet. The location of maximum turbulent kinetic energy approaching the surface at about r/D = 0.9 - 1.2 which characterizes the swirling jet at H/D = 2.

The current study investigates the optimization of solar stills (SSs) productivity under different levels of solar radiation intensity, film cooling flow rate and water depth. Taguchi method is applied to perform a minimum number of experiments and to find the optimal water depth and cooling rate that maximize the productivity of the SS. An orthogonal array, signal-to-noise ratio and analysis of variance (ANOVA) are used to investigate the influence of the operating parameters on the solar still productivity. Taguchi method and ANOVA result several that water depth is the most influencing parameter. Furthermore, the results show that increasing the solar radiation and water film cooling improve the productivity. However, increasing the flow rate more than 4 kg/hr has a slight effect on the productivity. On the other hand, decreasing the water depth leads to a great enhancement in the productivity due to the faster evaporation and condensation rates. The levels of the operating parameters under-investigation are selected as follows: solar radiation intensity (5587,5673 and 5741 W/m2/day), film cooling flow rate (2, 4 and 6 kg/hr) and water depth (0.5, 1 and 1.5 cm). The improvement in the productivity with film cooling was about 6.05% at the water depth (0.5 cm)