Study on gas diffusion emitted from different height of point source

Abstract

The flow and dispersion of stack-gas emitted from different elevated point source around flow obstacles in an urban environment have been investigated, using computational fluid dynamics models (CFD). The results were compared with the experimental results obtained from the diffusion wind tunnel under different conditions of thermal stability (stable, neutral or unstable). The flow and dispersion fields in the boundary layer in an urban environment were examined with different flow obstacles. Gaseous pollutant was discharged in the simulated boundary layer over the flat area. The CFD models used for the simulation were based on the steady-state Reynolds-Average Navier-Stoke equations (RANS) with kappa-epsilon turbulence models; standard kappa-epsilon and RNG kappa-epsilon models. The flow and dispersion data measured in the wind tunnel experiments were compared with the results of the CFD models in order to evaluate the prediction accuracy of the pollutant dispersion. The results of the CFD models showed good agreement with the results of the wind tunnel experiments. The results indicate that the turbulent velocity is reduced by the obstacles models. The maximum dispersion appears around the wake region of the obstacles.

An Efficient Diffusion Model for a Real-Time Gas Diffusion Simulation System

“…CFD models [1] are usually associated with complex parameter systems and large amount of computation, which does not apply to real-time application. FEM3 [2] is a numerical model developed primarily to simulate heavy gas dispersion in the atmosphere, such as the gravitational spread and vapor dispersion that result from an accidental spill of liquefied natural gas, but it needs very complex computation.…”

Τυρβώδης Ροή Και Διασπορά Ρύπων Στο Αστικό Περιβάλλον

“…Ο Yassin (2009a) εξετάζει τη ροή και διασπορά ρύπων από πηγή που βρίσκεται στα κατάντη κτιρίου. Παρουσιάζει αποτελέσματα από πολλές περιπτώσεις, για διάφορες καταστάσεις ευστάθειας της ατμόσφαιρας, για τρεις πιθανές γεωμετρίες (επίπεδη, παρουσία κτιρίου μορφής κύβου και παρουσία πλάκας) και για δύο πιθανά ύψη της πηγής.…”