Aerodynamic Equilibrium and Stability in Ventilation and Air Quality Control of Complex Urban Tunnels

Urban vehicular tunnels generally have a branched structure and complex nonlinear aerodynamics, the study of which is crucial for tunnel ventilation design and air quality control. In this study the research team aims to establish the aerodynamic equations describing the 1-D airflow distribution in such bifurcate tunnel systems. A novel piecewise-affine (PWA) approximation is proposed for the flow-dependent local pressure-loss coefficients at tunnel junctions. This enables the team to model the system via first-order ODEs with piecewise-quadratic polynomials. Based on this model, the team derives the sufficient condition for the uniqueness and stability of the steady-state solution of each ODE piece. This condition is easily verifiable given the tunnel parameters. The team will also show via numerical examples that there may exist multiple stable steady-state solutions for the entire system. The model provides a theoretical foundation for ventilation design and air quality control in complex tunnels as well as for analysis of other hydraulic network systems with similar structures.


  • English


  • Status: Completed
  • Funding: $57601
  • Contract Numbers:


  • Sponsor Organizations:

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590
  • Managing Organizations:


    Washington DC,   United States 
  • Project Managers:

    Kline, Robin

  • Performing Organizations:

    Cornell University

    Ithaca, NY  United States  14853
  • Principal Investigators:

    Gao, H

  • Start Date: 20171101
  • Expected Completion Date: 20181231
  • Actual Completion Date: 20181231
  • USDOT Program: University Transportation Centers

Subject/Index Terms

Filing Info

  • Accession Number: 01664975
  • Record Type: Research project
  • Source Agency: Center for Transportation, Environment, and Community Health
  • Contract Numbers: 69A3551747119
  • Files: UTC, RiP
  • Created Date: Mar 30 2018 10:28AM