Natural vs. blocked ventilation in naturally ventilated buildings - the effect of finite and decoupled sources

TL;DR

This paper investigates the complex dynamics of natural ventilation in buildings, focusing on how decoupling heat and mass sources affects flow behavior and ventilation states through advanced numerical simulations.

Contribution

It extends previous theoretical analysis by numerically exploring turbulent buoyancy-driven flow with decoupled heat and mass sources in naturally ventilated buildings.

Findings

Decoupling heat and mass sources alters flow dynamics significantly.

Numerical experiments reveal complex transition behaviors and hysteresis.

Flow simulations demonstrate the impact of source decoupling on ventilation efficiency.

Abstract

Naturally ventilated buildings harness freely-available resources such as internal buoyancy gains and wind forcing in achieving comfortable interior conditions. Although these resources are free, they are time-variable and can be difficult to control. As a result of this the nonlinear interplay between sometimes competing resources may lead to sub-optimal ventilation states. This problem has been explored by a number of previous researches e.g. Flynn & Caufield (Building and Environment, 44, 216-226, 2009) who, in studying these ventilations states, demonstrated complicated transitions characterized by hysteresis even for the simple case of a one-zone building. The objectives of this research are to extend the previous (theoretical) analysis by conducting complementary numerical experiments using sophisticated algorithms capable of describing turbulent, buoyancy driven flow. A further objective of this study is to specifically decouple the source, which was previously assumed to supply both heat and mass to the interior space. Rather, the flow dynamics in a case where heat and mass are supplied independently are examined.