Expanding the FDS Simulation Capabilities to Fire Tunnel Scenarios Through a Novel Multi-scale Model

Abstract Computational Fluid Dynamics (CFD) is widely used to simulate tunnels and partially substitute on-site tests. As technology advances, new application opportunities appear; some examples are the optimal operation of ventilation emergency systems, risk assessment training operators. Even when computational capacity computers has grown, CFD still constrained by large amount resources needed in long tunnels. This introduces a need for methods able reduce time required simulations. To face this need, novel 1D–3D multiscale model presented paper. The incorporates code Whitesmoke into FDS (Fire Simulator) through direct coupling. manages fluid dynamics, temperature concentration species 1D portion, while calculates these fields portion where fire occurs. Using model, computation reduced, proportionally length domain. Also, additional simulation capabilities particularly useful tunnel analysis obtained. Some characteristics pressure boundary conditions can be easily imposed at portals or shafts; characteristic curves fans/jet-fans included, also considering degradation effects due smoke propagation; piston effect properly considered. Our research verifies most its capabilities, clarifying limitations criteria set domain analysis. final step, tested with cross section 4.8 m 600 2 MW fire, comparing performance full 3D simulation. difference velocity minimal domain, making It good way optimize resource usage Furthermore, more than 50%.