air flow distribution

In this paper, three-dimensional air flow distributions in a typical island platform under both natural and mechanical ventilation operation modes were simulated for the whole process of the train entering, staying in and departing from the platform. The mechanical ventilation modes include over-platform supply/under-platform exhaust (OSUE) and overplatform supply/over- platform exhaust (OSOE). Based on the data obtained from the simulations, the effects of natural and mechanical ventilation system on platform air distribution were analyzed.

The Particle Streak Tracking System (PST) is a fast method to measure two- and three-dimensional velocity fields in room air flows with measuring areas up to 5 m2. The two-dimensional method works with a single pulsed white light sheet and one digital camera. For three-dimensional velocity measurements in planes a laser light sheet system using three separate laser sheets with two different wavelengths and two CCD-cameras is employed. To visualise the flow helium filled bubbles are used. A description of the set-up will be given and the data evaluation process will be explained.

The objective of this research is to investigate air flow distribution inside a light weight test room which is single sided naturally ventilated. The ventilation rate into the room is controlled by adjusting four sets of louvres. The local outside air temperature, humidity, pressure, wind velocity and direction were measured. Inside the room the velocity and direction of the inflow air across the high and low level openings, temperature and velocity distribution at four locations and six levels across the room were recorded.