جستجوی مقالات مرتبط با کلیدواژه "جسم متخلخل" در نشریات گروه "مکانیک"

Among the different methods of water supply, extracting water from atmospheric fog has recently received more attention from scientific communities due to its advantages and unique features. In this method, water droplets are trapped and separated from the air using metal meshes. The main challenge facing this technology is the low efficiency of water harvesting from humid air. To overcome this issue, the idea of using a metal porous collector has been tested in the presence of an electrostatic field. Parameters such as the porosity percentage of the collector, airflow speed, electric field intensity, and the distance between the emitter and the collector (field distance) on the water harvesting efficiency were studied experimentally. In the range of investigated porosities, the efficiency of the fog collector has its maximum value with a porosity of 95.6%. Also, reducing the field distance increases the efficiency. Investigating the effect of electric field voltage on the efficiency of the device showed that with the increase in voltage from 15 to 24 kV, the efficiency increases from 21% to more than 42%. At this voltage, the phenomenon of voltage saturation has occurred, so that a further increase in voltage does not have much effect on the efficiency. Investigating the effect of flow speed showed that the maximum efficiency of the device was achieved at a speed of 1.1 m/s.

In this paper, drying of the moist object is numerically investigated in the forced convection with and without the electric field. Finite volume method is used to solve governing equations of electric, flow, temperature, and the concentration fields in flow phase, as well as the temperature and the moisture fields in the moist object. In this study, the effect of applied voltage and the arrangement of the emitting electrode are evaluated. The results indicated that in presence of electric field, the increment of the applied voltage for 18 kV to 24 kV, the mass transfer from porous object 3.78 times and power consumption 7.96 times are increased. It is also found that the drying rate is increased by decreasing the distance between the emitting and collecting electrodes. According to numerical results, the mass transfer enhancement is usually accompanied by penalty of electric energy consumption. Therefore, the specific energy consumption has been evaluated as final criterion. It is shown that the specific energy consumption of the electrohydrodynamic drying process has been remarkably affected by the changing of the emitter arrangements. Finally, an optimum arrangement has been introduced as the affordable arrangement.