chapter  4
109 Pages

Modeling of ventilation airflow

Microscopic methods, on the other hand, are based on continuum descriptions of mass, momentum and energy transport that are defined in terms of partial differential conservation equations. In principle, they provide the means to predict the details of both internal and external airflows in and around buildings, but because of the challenge of solving these demanding equations, the analyst must be satisfied with (approximate) analytical solutions for generic or elemental flow conditions within rooms, approximate numerical solutions for single or well-connected multiple rooms, and/or numerical solutions for airflows around buildings for approximate nearfield boundary conditions. Furthermore, because of practical computational limits, microscopic methods are typically, but not exclusively, applied to the analysis of steady snapshots of these airflow details.