Natural ventilation analysis of fully depressed partially covered highway for Overton Park, on I-40 through Memphis, Tennessee

This work investigates road vehicles pollution distribution in a naturally ventilated fully-depressed partially-covered-highway. The study is mainly concerned with the effects of the open area and the number of covered sections on pollution distribution. The study recognizes the importance of atmospheric conditions in controlling pollutants concentrations involved in such a design.

A steady state induced velocity model coupled with mass balances for the closed and open sections were used to develop a steady state model which calculates the concentration distribution of any pollutant over the tunnel system. The model was developed to a general computer program which handles any number of closed open sections with any assigned length and grade.

The model was used to find the effect of the number of closed open sections on the pollution distribution over the tunnel system. . Number of open closed sections is found to be effective in reducing pollution distribution at high values of the mass transfer coefficient but has small effect at small values of the mass transfer coefficient.

The model was applied to the Overton Park configuration where effect of traffic speed on pollution distribution was investigated. Results indicated that for freely flowing traffic and for high speeds pollution concentrations would be within the allowable limits.

The model as it stands gives reliable qualitative analysis and in order to achieve quantitative results the mass transfer coefficient needs to be investigated.