Transition from bi-directional to unidirectional flow in a doorway.

The air flow in a doorway is governed by density difference caused by temperature difference and pressure difference caused by mechanical ventilation. Tests have been carried out in a unique indoor test house where the room to room to temperature difference could be controlled very accurately with a new control system. In addition to these tests some tests were carried out in a scale model with water as the operating fluid. Two main criteria of unidirectional flow in a doorway have been explored:

CFD simulation of air velocity distribution in occupied livestock buildings.

In modem livestock buildings the design of the ventilation systems is important in order to obtain good air distribution. The use of Computational Fluid Dynamics for predicting the air flow and air quality makes it possible to include the effect of room geometry, equipment and occupants in the design of ventilation systems. However, it is not appropriate to include the detailed geometry of a large group of lying or standing animals affecting the air flow in the building. It is necessary to have relatively simple models of the animals, which are easier to implement in the computer models.

The influence of furniture on air velocity in a room - an isothermal case.

Using isothermal full-scale experiments and 3-dimensional CFD simulations it is investigated how normal office furniture influences the air movements in a mixing ventilated room. Two different types of inlets are used in the experiments and a set-up with normal office furniture is made. The set-up is simulated with one of the inlets where a volume resistance represents the furniture. The jet under the ceiling is investigated and it is found that the normal office furniture does not influence the air movements in the upper part of the room.

Turbulent force flow in an airblast storage room.

Forced air circulation in a storage room either with freezing/cooling or controlled atmosphere is usually turbulent because a high air change rate is generally required. The interaction between the turbulent air flow and the product layers plays an important role in the performance of the storage room. In this paper, a homogenous model based on the Brinkman-Forchheimer-extended Darcy equation for both fluid and porous layer is described, in association with the standard k-e turbulence model.

An Experimental Study on Chair Air Supplying

Displacement ventilation is acknowledged to be an efficient system for the removal of contaminants and excess heat from occupied zones of rooms, this system is aiming at supplying clean undiluted supply-air directly to the zone of occupation. Air flow rate, temperature and the design of the supply device strongly influence the parameters that determine thermal comfort. In the paper, one kind of displacement ventilation systems - ohair air supplying system is investigated.

Test Room and Measurement System for Active Displacement Air Distribution

A test room and measurement system were developed for the full-scale measurements of the active displacement air distribution. The room represents a 3-meter wide module of a larger hall. The requirements for the room included minimisation of the errors caused by air leaks, thermal conductance and flow obstacles. The measurement of the flow pattern is carried out with ultrasonic and thermal anemometers. Automated traversing system was built to move the sensors in the vertical symmetry plane of the room.

Detailed Experimental Data of Room Airflow with Displacement Ventilation

This paper presents a set of detailed experimental data of room airflow with displacement ventilation. These data were obtained from a new environmental test facility at the Massachusetts Institute of Technology (MIT). The measurements were conducted for three typical room configurations: a small office, a large office with partition, and a classroom. The experiment measured the distributions of air velocity, air velocity fluctuation, and air temperature by omnidirectional hot-sphere anemometers and contaminant concentrations by tracer gas at 54 points in the room.

Vents, ventilation drying, and pressure moderation.

The orientation, size, and nature of vents in screened exterior wall systems are important to wall performance because these characteristics affect venting, ventilation and pressure moderation. The ventilation of screened wall systems has received very little attention in Canadian building research. With funding from CMHC 's External Research Program, the B uilding Enginee ring Group at the Uni versity of Waterloo undertook an experimental and theoretical study of vents and venting in screened walls.