Tunnel Ventilation

5th OpenFOAM Workshop, Gothenburg, Sweden, June 21-24th, 2010Using OpenFOAM for Tunnel Ventilation Design

Jeannine Croll, 22/06/2010

ILF Consulting Engineers

The Company was established by Mr. P. Lsser in Innsbruck, Austria in 1967

In 1969 Mr. A. Feizlmayr joined the company, which became Ingenieurgemeinschaft Lsser-Feizlmayr (ILF), second office in Munich, Germany

Today ILF is a leading international, multidisciplinary engineering and consulting firm (100% privately owned)

Using OpenFOAM for Tunnel Ventilation DesignILF Group

Business Areas


Production facilities for oil & gas Pipeline systems

Tank farms and underground storage facilities

Refineries and petrochemical plants

Airports Roads Railway systems Tunnels and caverns Buildings and structures Alpine engineering

Water supply

Wastewater treatment & disposal

Waste treatment & disposal

Hydropower, dam andriver engineering

Thermal power plants Sea water desalination plants Renewable energy Climate protection

Transmission and distributionsystems

Offices and Projects Head offices in Innsbruck and Munich and more than 30 branch offices and

subsidiaries worldwide

Over 3,500 successful projects


officesprojects

Use of OpenFOAM in the Design of Ventilation Systems Use of 3D CFD calculations in support of conventional

1D analytical pressure loss calculations used to define fan performance

Evaluation of 3D flow behaviour in complex road tunnel caverns

Using OpenFOAM for Tunnel Ventilation Design3D CFD for Tunnel Ventilation Design

typical cross-section (50m)

jet fans

jet fan niche (30m), expanded cross-section

63.7m

lay-by (50m)63.5m

typical cross-section (50m)

51.2m

page 6

Bosruck Tunnel, Computation Domain Uni-directional traffic flow in the two-lane western tube of the Bosruck Tunnel

Investigation of flow characteristics in the vicinity of working jet fans and of resulting maximum flow velocities in the tunnel tube

Using OpenFOAM for Tunnel Ventilation Design3D CFD for Ventilation Design, Bosruck Tunnel

Bosruck Tunnel, Surface Mesh Tunnel geometry and surface mesh modelled with Blender

(3D computer graphics software) Extrusion of cells in entrance and exit surfaces to reduce number of volume cells

Lower resolution in less significant tunnel sections

Compromise to minimise aspect ratio of cells and number of volume cells


5,244Rectangles136,728Triangles141,972Number of cells

Surface Mesh

Bosruck Tunnel, Volume Mesh and Boundary Layer Generation of unstructured volume mesh (tetras) and boundary layer (stretched

prisms) with enGrid (mesh generation software produced by enGits)


Colour CodeTetras: red Prisms: green

1,375,848Prisms29,640Hexahedrons

5,151,513Tetras6,557,001Number of cells

Volume Mesh

Bosruck Tunnel, CFD Simulation Addition of a momentum source to model

thrust of jet fans Steady calculation, incompressible solver:

modification of original simpleFoam solver

k-omega SST turbulence model


Research Project, Longitudinal Ventilation System Consideration of radial heat conduction

and changing heat release

Two phase-model: air and concrete

Transient solver, calculation time: 1200 s

Application of heat source in OpenFOAM,solver chtMultiRegionFoam(< 5 min: linear rise, > 5 min: constant heat release)

Flow characteristics at entrance surface: 1.5 m/s, 288.15 K

Using OpenFOAM for Tunnel Ventilation DesignInvestigation of Temperature Curves in Case of Fire

tunnel gradient 1.5%

heat source (3mx2mx18m, 22.5MW)

cross-section: 53 m concrete layer

tunnel cross-section

Using OpenFOAM for Tunnel Ventilation DesignInvestigation of Temperature Curves in Case of Fire

Research Project, Longitudinal Ventilation System Temperature characteristics in the tunnel, simulation time 1200s

Using OpenFOAM for Tunnel Ventilation DesignThank you for your attention!

Documents

Tunnel Ventilation