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

This article addresses key physical processes associated with the propagation of high-average power laser beams in a maritime environment. A number of physical processes affect and limit the amount of laser energy that can be delivered to a target. These effects are interrelated and include thermal blooming, turbulence, and molecular/aerosol absorption and scattering. These processes affect the laser intensity profile by modifying the refractive index of the air, which causes the laser beam wave front to distort. Wave front distortion results in enhanced transverse laser beam spreading, and can severely limit the amount of energy that can be propagated. The maritime environment is particularly challenging for high energy-laser (HEL) propagation because of its relatively high water vapor and aerosol content. In the infrared regime, water molecules and aerosols constitute the dominant source of absorption and scattering of laser energy, and represent a limitation for HELs propagating in a maritime atmosphere.

The vapour absorption into the liquid falling film has occurred in various natural phenomena and its application has spread in various industries, such as the dehumidification and desalination industry. The complexity of flow dynamics, mass transfer, heat, and small dimensions of a liquid film has made its modeling and numerical simulation a key role in the investigation and studying of the effectiveness and improvement of the absorption process in a liquid film absorbent. In the present work, the effects of Reynolds number, wall temperature, and wall shape on the interfacial heat and mass transfer have been investigated. Numerical modeling has been performed using an unsteady Arbitrary Lagrangian-Eulerian interface tracking method by Fortran. The simulation results show that the deformation of the wall surface and the cooling of the wall temperature has a significant effect on the rate of gas vapor absorption into the laminar liquid film in comparison with the flat wall

In this paper, multi-objective optimization of the cooling and heating systems at the faculty of engineering of Arak University is investigated to increasing comfort and reducing the cost of energy. In the first step, the faculty building with 4 floors, 11800 square meters of infrastructure and 122 classrooms and rooms is modeled and the comfort and cost of the faculty are calculated. In the next step, a database of 2,000 faculties with different design variables was created and analyzed. Between the formed databases, buildings with the best objective functions are selected and presented in a Pareto front. Design variables are the 11 geometrical and non-geometrical factors affecting the comfort and cost of the faculty. The objective functions are the comfort, cost, and energy consumption. The results indicate that both absorption and compression systems have the ability to achieve acceptable levels of comfort, but the amount of energy consumed in the absorption chiller is higher than the energy consumption of the compression system, which indicates the necessity of using absorption systems in conditions of waste heat. Also, the results indicate that the absorption system, despite the higher energy consumption than the compression system, has lower energy consumption costs due to the difference between electricity and gas tariffs in Iran country and should be corrected.