Dissertation presentation Essay Example

Abstract

Even though underground train is highly beneficial with regards to passenger and good transport, but this system requires passenger safety and evacuation measures to adequately addressed. This paper involved CFD simulation of underground train. The aim of the project is to analyse the fires safety of underground trains. The objectives of the study were: Identifying credible fire scenarios for a metro train for simulation;FDS simulation to examine the severity of five different fire cases in an underground train way; analyzing the difference between fires occur in luggage area and fires breakout on or near the floor (seats) and examining the impact of the geometry of the tunnel. Under literature review various cases of train fire were discussed and there was also a review on train fire simulation among other things. Generally visibility was found to be affected within a very short time after starting of fire and also visibility effect was much faster in S fire than L fire. In cases 1 all cars completely affected at 87s; 67s for case2 and 65s for case 3. Temperature rise in the tunnel did not rise to dangerous for case 1 fire. Inside the cars it was observed that temperature relatively fast with the areas nearer to fire source having much higher temperature level.With the critical value being set at 800ppm it is seen that CO may not be an immediate concern when compared to visibility. In all the cases it was realized that there was a point when the HRR reached first a pick value followed by a rapid drop in HRR from there it rose to a maximum value. One of the recommendations was that underground train cars should have exhaust at the roofs so as to ensure that incase of fire the combustion products can be channeled out so as to increase the time in which the cars can remain safe for the occupants