Technical Application of a Multiphase Solver in the Compressible Flow of a Gaseous and a Liquid Phase

In this work the simulation of the compressible multiphase flow in a fire extinguishing system is investigated. Challenges with the simulation of these conditions include both algorithmic issues like the correct depiction of the momentum transfer between the gaseous and the liquid phase and practical issues like the compatibility with other software tools (e.g. CAD, meshing tools) in order to simulate such flows with an arbitrary mesh. Also the amount of cells needed for adequate resolution of the flow requires parallelization of the simulation in order to maintain reasonable calculation times.

Schematic sketch of the gas cylinder geometry for experiment and CFD (initial conditions)

The information of the movement of the liquid extinguishing material calculated by the simulation is characteristic for the subsequent progress in the pipes. Simulation results of an actual fire extinguishing process are compared to the experimental data.

Relative difference of pressure between Smagorinsky and Spalart Allmaras turbulence model at t = 0.1 ms