Publikationsdatenbank

Numerical determination of air exchange rate of and inside a naturally ventilated barn depending on incoming wind angle and barn’s length/width (2019)

Art

Vortrag

Autoren

Doumbia, Moustapha

Hempel, Sabrina

Janke, David

Amon, Thomas (WE 10)

Kongress

12th EFITA International Conference

Rhodes Island, Greece, 27. – 29.06.2019

Quelle

Conference Proceedings : digitizing agriculture : 12th EFITA-HAICTA-WCCA Congress 2019 — Edited by Dionysis Bochtis, Maria Lampridi, Aristotelis Christos Tagarakis, Charisios Achillas (Hrsg.)

Rhodes, Greece: EFITA-HAICTA-WCCA Congress, 2019 — S. 132–137

ISBN: 978-618-84798-0-7

Sprache

Englisch

Verweise

URL (Volltext): https://efita-org.eu/wp-content/uploads/2020/03/EFITA_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 investigate thecomfort of the animals inside. Yet the air exchange rate is still difficult to assess mainly because of fluctuating influence stimuli such as wind (speed and angle), temperature, barn geometry etc. The main objective of the BELUVA project, financed by the German Research Foundation, is to systematically address those influences. The present study has been carried out in order to investigate the impact of incoming wind angle on the air exchange rate of animal occupied zones of barns with different length/width ratios.A numerical model with quadrilateral and polyhedral grid cells (hybrid mesh) was set up in ANSYS Workbench. The numerical domain was divided into blocks for better meshing controls and quality. The influence of the roughness height was studied as well toreduce the numerical error related to the non-horizontal homogeneity of the velocity profile downstream.Going from this numerical model, the air exchange rate of the whole barn and of the animal occupied zones inside has been determined and compared for different cases. The cases distinct themselvesby threedifferent incoming wind angles (0°, 45° and 90°),threedifferent barn’s length (L) /barn’s width (W) (L/W=2,3,4) ratio and threedifferent velocity magnitudes(1, 3 and 5ms-1).The results showthat the influence of the velocity incident angle on the air exchange rate of the overall barn and the animal occupied zones inside can be classified in types at least for the 0° and 90° incident angles. This, depending on the L/Wratio, gives important information aboutthe heightof the local in air exchange rate.