Modelling

Summary

Main research question/goal

Animal houses need an efficient ventilation system. Natural ventilation, being the most energy efficient technique, is generally recommended. However, natural ventilation is a complex process. Controlling the ventilation rate still poses problems that require further research. The goal of this doctoral research project is to study the airflows in and around naturally ventilated buildings and to determine the optimal configuration of the ventilation openings. A reliable estimation of the ventilation rate is also needed in light of the environmental impact of animal houses (emissions of gases, particulate matter and odour).

Research approach

To gain more insight into the interaction between naturally ventilated agricultural buildings and their environment (air flows, ventilation capacities, emissions etc.), we employ three research strategies:

1. air flow measurements in and around cattle barn scale models in a wind tunnel (Figure 1);
2. ammonia concentration measurements during various experimental conditions in ILVO’s emission lab “EmiL” (Figure 2/top);
3. computer simulations of the above using Computational Fluid Dynamics (CFD) (Figure 2/bottom).

Integration of the results from these different methods leads to a better understanding of the topic.

Relevance/Valorisation

This project provides fundamental scientific support for the development of a practical measuring technique for the ventilation rate of naturally ventilated animal houses (NatVent, IWT-LO-090946). Such a technique allows for better control and management of the natural ventilation process, which should help to (re-)introduce this technique into animal husbandry. Furthermore, this technique generates more reliable emission measurements, which is important for policy purposes. A CFD model of the environment around the building can also assist in the development of an evaluation framework, which is useful for policy-making about farm exploitations (permits). These aspects are also research priorities of the Agriculture and Fisheries department and the ‘Witboek Landbouwonderzoek’.

Project administration

Researcher: Merlijn De Paepe

Funding: Ilvo

Project duration: 01.01.2009 - 31.12.2012