Part XVI: Street Canyon Pollution
Physics of pollutant dispersion in urban street canyons — from vortex flow regimes through the OSPM analytical model to k-epsilon turbulence, health impact assessment, and MFG-based pollution-aware routing.
Part Overview
Characterizes canyon geometry by aspect ratio \(\alpha = H/W\) and four flow regimes governing pollutant trapping. Derives the OSPM formula \(C = C_D + C_R + C_B\) from Gaussian plume Green's functions, extends to k-epsilon turbulence closure, and connects to WHO health limits and MFG pollution-aware Wardrop equilibria.
Key Topics
- • Canyon aspect ratio \(\alpha = H/W\)
- • Four flow regimes
- • Vortex circulation
- • OSPM formula \(C = C_D + C_R + C_B\)
- • Gaussian plume Green's function
- • k-\(\varepsilon\) turbulence model
- • WHO health limits
- • MFG pollution-aware Wardrop
3 chapters | From canyon physics to health impacts | Where air quality meets urban geometry
Chapters
Chapter 1: Canyon Flow Regimes
Classifies street canyon flow by aspect ratio \(\alpha = H/W\) into isolated roughness, wake interference, skimming, and multi-vortex regimes. Derives vortex circulation patterns and their implications for pollutant trapping and ventilation.
Chapter 2: Advection-Diffusion & OSPM
Derives the Operational Street Pollution Model from the advection-diffusion equation using Gaussian plume Green's functions. The three-component formula \(C = C_D + C_R + C_B\) decomposes concentration into direct, recirculation, and background contributions.
Chapter 3: Turbulence & Health Metrics
The k-\(\varepsilon\) turbulence model for Reynolds-averaged canyon flow, calibrated against wind-tunnel data. Connects predicted concentrations to WHO health limits and develops MFG pollution-aware Wardrop routing for exposure minimization.