English

The nesting of a new zonal model within a multizone model has allowed an increased resolution in the prediction of local air flow velocities, temperature and concentration distributions between rooms and within rooms.

This article describes a reliable tool for analysing and designing natural ventilation systems, based on fundamental flow equations : mass balance, energy conservation and momentum.

For the study of single-sided natural ventilation, a CFD model along with analytical and empirical models have been used, to determine the effects of buoyancy, wind, or their combination on ventilation rates and indoor conditions.

The new model of the COMIS program has been modified, it allows individual rooms to be divided into smaller zones. This new program has been evaluated and the results have been compared to those from other zonal and CFD models.

This paper describes a new tool, ils architecture and its predictive performance. BACH is a computational tool for air flow simulation in and around buildings in the early stages of the design process.

Several thermal building simulators also allow coupled modeling of bulk air movements using airflow network models.However, solving the combined flow and thermal problem can be problematic, both in the context of traditional building simulators and for modern environments, where both airflow and thermal models are formulated as sets of differential-algebraic equations (DAE). For variable-time-step DAE-basedsimulators, difficult coupled problems often lead to small time steps and slow simulations.

This paper presents the study of a local exhaust ventilation system with plain (unflanged) and flanged hoods. Centerline velocity and velocity contours in front of exhaust hood openingswere measured and compared to other previously reported results. Centerline velocity correlations are derived for a full range of hood axes. The effect of turbulence intensity and surrounding equipment on the velocity contours is also analyzed. Capture velocity for three different types of contaminant particles (saw dust, wheat flour, and sand) was determined.

The purpose of continuous fan operation is to bring in fresh outdoor air to the conditioned space in order to maintain acceptable indoor air quality. Ventilation not only uses more energy, but it also impacts air distribution system efficiency.This is partially due to various system interactions. The objective of this paper is to quantify the impact of continuous fan operation on energy use and distribution efficiency by introducingtwo new parameters: energy use ratio (EUR) and distribution efficiency ratio (DER).

Velocity and turbulence intensity profiles of the airflow inside a section of a narrow body (737) aircraft cabin were measured using the particle image velocimetry (PIV) technique.In this paper the measurement technique is described and the results are presented and discussed. The purpose of this study was to provide accurate experimental data for validation of the computational fluid dynamics (CFD) codes developed for this application.

This paper gives an overview of sources of indoor particulate matter (PM) and its effects on occupants. Studies indicate that outdoor PM contributes to indoor PM, yet a large fractionof indoor PM is generated indoors. The ratio of indoor to outdoor PM concentrations (I/O ratio) varies substantially due to different indoor conditions and PM spatial distributions.Real-time investigation using multiple point sampling technique is needed for better understanding of PM spatial distribution.