Numerical prediction of indoor temperature stratification
In many buildings, displacement ventilation is used so that contaminantscan be separated from occupied space [1, 2]. A fundamental characteristicof displacement ventilation is a layer of stratified fluid that separates theoccupied zone from the contaminated zone, marked by a density gradientusually...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
MULTIPHYSICS
2016-03-01
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| Series: | International Journal of Multiphysics |
| Online Access: | http://journal.multiphysics.org/index.php/IJM/article/view/65 |
| Summary: | In many buildings, displacement ventilation is used so that contaminantscan be separated from occupied space [1, 2]. A fundamental characteristicof displacement ventilation is a layer of stratified fluid that separates theoccupied zone from the contaminated zone, marked by a density gradientusually due to temperature differences in the two zones. Becausebuoyancy is a dominant effect in these situations, natural rather than forcedventilation is commonly used.This paper presents a series of simulations studying the prediction ofsteady-state stratification in a room ventilation case. Following on fromwork performed by Iial-Awad [3], numerical simulations coupled with a 2-equation turbulence model were employed to predict the steady-statetime-averaged temperature distribution and stratification layer height in aroom subject to two momentum sources at different temperatures. Theroom has been simulated with different levels of idealism to examine theeffect boundary condition assumptions have on the predictive accuracy ofthe simulation compared to the work of Iial-Awad [3].It was found that the assumption of adiabacity of the room caused thepredicted vertical temperature profile to be highly idealistic, with the flowstratified into two discrete layers across a sharp interface. The addition ofheat loss boundary conditions and thermal radiation modelling causes thepredicted temperature profile to more closely match that produced in theoriginal experimental work. |
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| ISSN: | 1750-9548 2048-3961 |