Application of CFD Tools to Optimize Natural Building Ventilation Design

Abstract

The use of natural ventilation systems may contribute considerably to the reduction of the energy consumption, while providing adequate comfort levels and hygiene standards for the occupants. Computational Fluid Dynamics (CFD) techniques are becoming increasingly attractive in the design of ventilation systems. In this work, tests on a validated CFD model, which simulates the air flow inside a standard building, were carried out in order to obtain a suitable tool to predict ventilation performance and therefore optimize the building ventilation design. The model solves the mass, momentum and energy for the air flow, coupled with the k-ε turbulence model. The equations are solved by a FV discretization technique in a structured grid. Appropriated boundary conditions and the dimension of the domain were studied for more accuracy in numeric simulation. The influence of the free stream velocity profile and wind direction upon the efficiency of a natural ventilation system under isothermal conditions has been tested. The results obtained so far confirm the validity of the implemented model and its possible use for the optimal design of natural ventilation systems.