جستجوی مقالات مرتبط با کلیدواژه « reflector » در نشریات گروه « مکانیک »

Solar energy is the most abundant source of energy among renewable energies, which can be directly converted into electricity by solar modules. To tackle the low energy output of solar modules in places where there are not enough spaces to install many solar modules, the use of reflectors is recommended. The use of reflectors increases the solar radiation on the surface of the module, hence will boost its power output. In this study, two-dimensional simulations were performed using ANSYS Fluent 2021 R2 package software in which the effects of a flat plate, parabolic, and hybrid reflectors on the temperature and efficiency of the module were investigated. The numerical simulation of the current study was validated against an experimental case study. Although there were so many simplifications and assumptions for the validation, the maximum deviation between the present numerical result and the experimental was less than 3.86%, which certifies the results of this paper. Based on the output, the surface temperature of the solar module with ˚85 flat plate reflector and ˚85 parabolic reflector reached 360.82 (K) and 371.11 (K), respectively, while the temperature with ˚50 reflector for both parabolic and flat plate modes reached 345.94 (K) and 346 (K), which are approximately equal. It was also observed that with increasing the angle of flat and parabolic reflectors, the module temperature increased, and parabolic reflectors had higher temperatures at higher angles. The module temperature using a type 6 reflector increased by 7.14% and 0.92% compared to the ˚80 flat plate reflector and ˚80 parabolic reflector, respectively. In terms of efficiency, since reflectors will intensify the solar radiation on a solar module surface, it will enhance the operating temperature of the module so that in all cases with reflectors, the efficiency will drop from an initial maximum value to a certain minimum value. This drop is more significant in the parabolic reflectors compared to the flat plate reflectors.

Reflectors are a very important tools in counteracting the space borne or airborne SAR imaging systems. Because they can be used in the form of decoy and camouflage protection designs due to their high level RCS. The remarkable thing on this mission is that the SAR radar is capable of sending the wave to earth in any direction, with any incident angle and in any frequency band, and capturing sensitive areas. The design of such an all-directional, multi-band reflector, and wide angles reflector is very complicated because the reflex function depends on various parameters such as the dimensions, shape and material of the reflector, the frequency, the incident angle, and the polarization of the radiated wave. Existing refractors generally have a high RCS in a particular direction at a specific frequency and at a narrow viewing angle. In this paper, we will attempt to design a refractor of all directions, multiple bands and wide angles using shape structures.