Natural ventilation inside train tunnel

الملخص EN

The need for rapid and comfortable urban mass transportation has been increasing parallel to the increasing duration of traffic in the twentieth century.

Underground transportation is one of the most effective and rapid means of urban mass transportation.

Today, more rapid transport systems involving subway facilities are so popular that every year a transportation line is planned, design and built.

In Egypt, the underground train (Tunnel Train) suffers from lots of passengers, exceeding one hundred passengers in each carriage at rush hours.

The mechanical ventilation in the system of the carriage is unable to remove the excess heat and humidity, especially in summer seasons.

Therefore, the need for an additional natural ventilation system is necessary to create comfortable environment inside.

This paper discusses the natural ventilation of the underground train experimentally and theoretically.

In the experimental work, a train model was fabricated (using Plexiglas to scale 1 : 30 ) and an electric heating plate was fixed in the floor of the train.

Different cases of window vanes location were studied by measuring the temperature of the heated plate (33 points) and calculating the average temperature for each case, which gave a guide for ventilation.

In the theoretical work, the software ANSYS Flotran [1], was used to solve the problem using the finite element and with 50,000 nodal points.

The air flow distribution inside the train was presented in the form of contours and vectors.

The results showed the optimum vanes location to give the most efficient air movement inside the train resulting in a sensible temperature reduction of the heated plate inside the model.