Significant questions in predicting room air motion.


Numerical prediction of airflow patterns and ventilation effectiveness in an open office environment.

Numerical modelling is performed to predict air movement, thermal comfort level and contamination distribution within an open office space. The office located in the building interior has a concentrated thermal load at its center and is conditioned by cool air delivered from a ceiling-mounted linear diffuser. the air velocity and temperature distributions and contaminant dispersion in the office are calculated for three different cooling loads and air exchange rates with a three-dimensional turbulent finite difference model.

An evaluation of a computer code for predicting indoor airflow and heat transfer.

The evaluation of a code can be done by investigating two items: solving the correct equations and solving equations correctly and eficiently. An indoor airflow code VentAirI has been developed and is evaluated here. An evaluating procedure is suggested. The code is characterized by the standard high-Reynolds-number k-E model with wall function, the two-band radiation model and the SIMPLE algorithm. Test examples are: 1. A three-dimensional forced convection problem (Re=5000), 2. A natural convection problem (Ra=5 *10^10), 3.

Models for the prediction of room air distribution.

The paper describes work on simplified design methods made in connection with the International Energy Agency programme "Air Flow Pattern within Buildings", Annex 20, subtask 1. It is shown that simplified models are able to indicate design values as the maximum velocity in the occupied zone and penetration depth of a non-isothennal jet in a room. The design according to throw of an isothermal jet is a fully developed method which has a sufficient level of accuracy when it is used in regular rooms.