airflow

Nowadays, the ceiling slot diffuser is very popular in offices. However one of the problems, for the producer and designer of linear diffusers, is to determine and specify correctly the throw-length data, in order to achieve optimal air movement in the occupied zone. Here, experimental studies were conducted to identify the variation characteristics in jet behaviour for ceiling slot diffusers. Nine cases, covering different aspect ratios, were measured under isothermal conditions in two test rooms using traversing measurement systems.

Within the Belgian Radon Programme the Belgian Building Research Institute is responsible for theinvestigation of techniques for prevention and mitigation of radon problems in dwellings. One of themost regular actions is the installation of a sub-slab depressurisation (SSD) system. As there are noready-to-use systems available on the Belgian market, a system has to be designed for every specificsituation.

This paper presents a numerical study of the coupled airflow and thermal environment in asemi-enclosed space surrounded by buildings. Our numerical simulation couples the heat transfercalculation and the computational fluid dynamic (CFD) airflow simulation in which a RNG(renormalization-group) k-? model is used. Both the solar radiation and building/ground thermal storagewere considered in the heat transfer part.

We describe the implementation of a model reduction tool within a software dedicated tothermal and airflow simulation. The goal is to allow the use of more detailed models. Wecompare experimental results and simulations results. We show the usefulness of the balancedreduction model for thermal and airflow simulation.

This study compares the contaminant concentration obtained from simple models with contaminant concentration fields obtained from CFD simulations, for various rooms and source configurations. Airflow and contaminant distributions were simulated.

This paper describes a numerical model that takes into account the indoor air moisture and its transport by the airflow, within an enclosure. That model is a potential useful tool for correctly estimating the indoor environment in steady and homogeneous thermal conditions.

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.

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.

The impact of infiltration and ventilation flows on energy use in commercial buildings has received limited attention. One of the reasons for this lack of study is that the commonly used programs for estimating the energy use of buildings do not incorporate the interzonal airflow modeling techniques
required to adequately account for the effect of these factors on energy usage. To address this issue and provide insight into the impact of these flows, the CONTAM airflow modeling tool