- Author
- Voigt, U. | Wolf, H.
- Title
- Verfahren zur Berechnung der Offnungen bei industriellen Hallenbauten im Brandfall. [Method to Calculate the Size of Openings for Smoke and Heat Release Out of Industrial Halls in Case of Fire.]
- Journal
- VFDB, No. 1, 25-31, February 1991
- Keywords
- corridors | smoke | heat release | mathematical models | temperature | density effects | fire gases
- Abstract
- To achieve the aimed at smoke- and heat release out of a room in fire the buoyancy resulting from differences of temperature or density can be used effectively. Therefore tests were made to work out a simplified mathematical model to simulate such a fire and to get the connection between temperature and density of the fire gas layer and the transformed amount of fire substances per time unit. They were transferred into a computer program. Basis of these model equations are the mass and enthalpie balances on the differential time element. A system of two coupled first order differential equations was derived for fire gas temperature and thickness of the fire gas layer as a function of time. This system was resolved by using a free-jet model for the smoke expansion as an initial value problem. Verification of this model was made by fire tests in a 1000 m fire research hall and in a 200 m test stand. It was found out, that the mathematical model is able to predict the temperature and the thickness of the fire gas layer with an insecurity factor of 10-20%. The mathematical model as well as the EDP-programe has been confirmed in solving problems of smoke- and heat transfer.