МОДЕЛИРОВАНИЕ ДВИЖЕНИЯ ВОЗДУШНЫХ ПОТОКОВ В ПОДЗЕМНЫХ СООРУЖЕНИЯХ МЕТРОПОЛИТЕНА ПРИ ПОЖАРЕ

Аннотация

The modeling of movement of airflows during the fire in underground constructions of metropoliten by the numerical methods of markers and cells and Simpler-method of Patankar is considered in the paper. By taking into accounts the thermal resistance and depression of the inertial forces an analytical expression of the dynamics of gas flow in the tunnel, depending on the source of forced and free convection, is obtained. It is shown that the stabilization period of ventilation in some cases is commensurable to the time of evacuation from the tunnel, creating an additional threat to their security. It has been found out that carrying out of air maneuvers during the evacuation may deteriorate the thermal and gas environment in the tunnel. Therefore the choice of emergency operation should be performed only after the forecast of the results of its implementation, taking into account the duration of the stabilization period. The proposed model of plane flow of gas in the technical and commercial buildings of metropoliten allows investigating the velocity field at different positions and sizes of arbitrary heat sources, both in presence and in absence of forced ventilation. This method of numerical simulation of plane flow can be used for fire conditions in the rolling track in tunnels for the purpose of prediction of smoke plumes during the fire development.

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