Sharif Digital Repository

Fire in enclosures is one of the most important disasters due to the presence of human and physical risks, so, investigation of the firefighting scenarios in this case has much importance. In the present study, novel enclosures fire suppression scenarios are simulated using computational fluid dynamics (CFD). The simulations have two major categories. In the first part, performance of different natural ventilation, positive pressure ventilation (PPV) and negative pressure ventilation (NPV) scenarios, which are new methods in firefighting, are evaluated and compared. In this part, the influence of different parameters like geometry, position of inlet and outlets and fire heat release rate... 

Fires in buildings and closed environments are considered as the most important types of fires due to the possibility of the presence of people and the possibility of life-threatening. Understanding and predicting fire behavior is critical to preventing damage. Backdraft is a special phenomenon of fire that occurs in a chamber with limited ventilation. In a closed environment where there is fire, over time, due to the closed doors and windows, the oxygen required for combustion decreases and as a result, semi-combustible materials can be dangerously exposed to the environment with flammable vapors and gases. Fill and when sufficient air reaches this chamber, a sudden explosion or the same... 

Positioning refers to the process of estimating the receiver coordinates aiming for an accurate understanding of the surrounding environment. This branch of science has attracted considerable attention in recent years. Today, the influence sphere of positioning is so expanded that encompasses applications in daily life (e.g., navigation) as well as commercial and even military fields. Global Positioning System (GPS) is the most widely used tool in real-time positioning. Because GPS imposes great measurement errors in challenging conditions (e.g., turbulent water environments), alternative methods such as methods based on Wi-Fi, Bluetooth, and visible light have been proposed. Benefiting...