Publication Database

Prediction of the local air exchange rate in animal occupied zones of a naturally ventilated barn (2019)

Art

Buchbeitrag

Autoren

Doumbia, Moustapha

Hempel, Sabrina

Janke, David

Amon, Thomas (WE 10)

Quelle

Conference Proceedings : sustainable decisions in Bio-economy — Edited by D. Bochtis, D. Aidonis, M. Lampridi, D. Kateris (Hrsg.)

Rhodes, Greece: Commission Internationale de l'Organisation Scientifique du Travail en Agriculture (CIOSTA), 2019 — S. 29–34

ISBN: 978-618-80440-9-8

Sprache

Englisch

Verweise

URL (Volltext): https://efita-org.eu/wp-content/uploads/2020/03/CIOSTA_Proceedings_e-book.pdf

Kontakt

Institut für Tier- und Umwelthygiene

Robert-von-Ostertag-Str. 7-13
14169 Berlin
+49 30 838 51845
tierhygiene@vetmed.fu-berlin.de

Abstract / Zusammenfassung

The air exchange rate is an important parameter in order to evaluate the gas emission of naturally ventilated barns. At the same time, understanding the flow inside such barns helps to evaluate the comfort of the animals inside. In this context, the local air exchange rate in subvolumes of the barn (i.e. individual animal occupied zones) is far more interesting than the total air exchange rate. Yet even the total air exchange rate is difficult to assess mainly because of fluctuating influence stimuli such as wind (speed and direction), temperature, barn geometry etc. One objective of the BELUVA project, financed by the German Research Foundation, is to address those influences and derive a parametric function for local air exchange rates. The functionwill further permit to answer questions associated with precision livestock farming. For example, for a given length/width ratio of a barn and a given inflow speed and angle, in which animal occupied zones a supporting mechanical ventilation must be switch on. The present study has been carried out in order to evaluate the impact of incidentwind angle and barn’s length/width ratio on thelocal air exchange rate in animal occupied zones of barns. Beforehand the numerical model has been validated with measurements done inside a boundary layer wind tunnelwith a down sized 1/100 barn. Threedifferent incidentwind angles (0°, 45° and 90°) and threedifferent ratios of barn’s length (L) /barn’s width (W) (L/W=2,3,4) have been considered. The results of this simplified model show that, while the barn’s overall air exchange rate is independent of the length to width ratio, the onesfor animaloccupied zones inside the barn arenot. The local air exchange rate depends strongly on the position inside the barn and the velocity incident angle.A model extension towards a full-scale building with surroundings and including the effects of animals as obstacles and heat sources is on-going in order to further increase the accuracy of the predicted local air exchange rates.