TY - JOUR T1 - Offering a method for reducing pollution and criterion for evaluation of ventilation flow in multilevel enclosed parking lots TT - ارائه راهکار کاهش آلودگی و معیار سنجش جریان تهویه در پارکینگ ‌های بسته چندطبقه JF - mdrsjrns JO - mdrsjrns VL - 16 IS - 7 UR - http://mme.modares.ac.ir/article-15-6160-en.html Y1 - 2016 SP - 285 EP - 296 KW - Pollution dispersion KW - Numerical simulation KW - air inlet position KW - exhausts position KW - jet fan N2 - The management of air quality in enclosed parking lots has many challenges such as increasing pollution concentration and pollution movement between floors. In this article, the complete calculation of ventilation system in multilevel parking lots is presented and the effect of supply and exhaust vents height on pollution concentration and movement is investigated by using numerical simulation. Also a new criterion for recognition of flow pattern is presented. In the numerical simulation, the conservation equations are solved by using openFoam. For validating the numerical simulation, the results are compared with available experimental results. The comparison of results is showed good accuracy of numerical simulation. After that, the common multilevel parking lots are introduced and the effect of supply and exhaust vent heights on the amount of pollution in these parking lots are investigated. The results showed that, if the supply vents are installed on the non-dimensional heights of about 0.55 and exhaust vents are installed on the non-dimensional heights of about 0.55 to 0.7, the best ventilation flow pattern in the multilevel parking lots is obtained. Furthermore, by using the novel method of this paper, the ideal bulk flow velocity for development of piston flow in parking lot is obtained and the flow pattern is tend to piston flow by optimizing the supply and exhaust vent heights. M3 ER -