SIMULATION AND MEASUREMENT OF ROAD TUNNEL VENTILATION

A computer program for PC has been prepared to simplify studies of air flows in road tunnels and the related problem of pollution concentrat ion due to emission from vehicles. Results from simulations include ai r pressures, flow rates, and pollution concentrations along the tunnel . Input data are tunnel geometry including flow friction factors and l oss coefficients, plus traffic and emission data and air pressures at boundaries. The program has been prepared in the IDA environment for m odular simulation. All mathematical models have been formulated in the Neutral Model Format (NMF) [Sahlin 1994]. The program has been valida ted by comparisons with older programs (Malmstrom 1980). Advantages of the new program, as compared to traditional programs, are its great f lexibility, ease of maintenance, and extendibility, as well as the ver y moderate implementation time. It has proved to be a useful tool for studying alternative ventilation concepts for road tunnels. Air flow r ates have been measured in part of the ''Soderledstunneln,'' a much-us ed road tunnel in central Stockholm. The measurements were made with t racer gas technique, which made it possible to measure without disturb ing the traffic flow through the tunnel. The measurements have been co mpared to simulations of the air pour. (C) 1997 Elsevier Science Ltd.