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

Transcription

1 5 th OpenFOAM Workshop, Gothenburg, Sweden, June 21-24th, 2010 Using OpenFOAM for Tunnel Ventilation Design Jeannine Croll, 22/06/2010

2 ILF Group 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) page 2

3 ILF Group Business Areas Production facilities for oil & gas Pipeline systems Tank farms and underground storage facilities Refineries and petrochemical plants Water supply Wastewater treatment & disposal Waste treatment & disposal Hydropower, dam and river engineering Thermal power plants Sea water desalination plants Renewable energy Climate protection Transmission and distribution systems Airports Roads Railway systems Tunnels and caverns Buildings and structures Alpine engineering page 3

4 ILF Group 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 page 4

5 3D CFD for Tunnel Ventilation Design 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 page 5

6 3D CFD for Ventilation Design, Bosruck Tunnel 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 jet fan niche (30m), expanded cross-section 63.7m² typical crosssection (50m) 51.2m² lay-by (50m) 63.5m² typical crosssection (50m) jet fans page 6

7 3D 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 Surface Mesh Number of cells Triangles Rectangles 141, ,728 5,244 page 7

8 3D CFD for Ventilation Design, Bosruck Tunnel 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) Volume Mesh Number of cells Tetras Prisms Hexahedrons 6,557,001 5,151,513 1,375,848 29,640 Colour Code Tetras: red Prisms: green page 8

9 3D CFD for Ventilation Design, Bosruck Tunnel 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 page 9

10 Investigation of Temperature Curves in Case of Fire 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, K tunnel gradient 1.5% cross-section: 53 m² concrete layer tunnel cross-section heat source (3mx2mx18m, 22.5MW) page 10

11 Investigation of Temperature Curves in Case of Fire Research Project, Longitudinal Ventilation System Temperature characteristics in the tunnel, simulation time 1200s page 11

12 Thank you for your attention!