Atmospheric Wind Field Modelling with OpenFOAM for Near-Ground Gas Dispersion

CFD simulations of near-ground gas dispersion depend significantly on the accuracy wind field. When simulating fields with conventional RANS turbulence models, velocity and profiles specified as inlet boundary conditions change rapidly in approach flow region. As a result, when hazardous materials are released, extent areas is calculated based an that differs from defined. To solve this problem, model consistent was developed to ensure horizontally homogeneous flow. Instead logarithmic vertical profile, power law used overcome problem negative velocities would be for heights within roughness length. With this, distance wall-adjacent cell midpoint has higher than length solved, so high grid resolution can ensured even region which required simulate dispersion. The evaluation using German guideline VDI 3783/9 tunnel experiments realistic obstacle configurations showed good agreement between measured values ability achieve homogenous