openfoam workshop, gothenburg, sweden, june...

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. Lässer in Innsbruck, Austria in 1967

• In 1969 Mr. A. Feizlmayr joined the company, which became “Ingenieurgemeinschaft Lässer-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


offices

projects

� 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

63.7m²

lay-by (50m)63.5m²

typical cross-section (50m)

51.2m²

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


5,244�Rectangles

136,728�Triangles

141,972Number 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 Code

Tetras: red Prisms: green

1,375,848Prisms

29,640Hexahedrons

5,151,513Tetras

6,557,001Number 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 m² 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 Design

Thank you for your attention!

openfoam workshop, gothenburg, sweden, june...

Documents