Perforated Ventilation Ducts: Part 2, Validation of an Air Distribution Model

• Published in: Journal of agricultural engineering research 1997-09, Vol.68 (1), p.29-37
• Main Authors: El Moueddeb, K., Barrington, S., Barthakur, N.
• Format: Article
• Language: English
• Subjects: Agricultural machinery and engineering; Agronomy. Soil science and plant productions; Air conditioning. Ventilation; Applied sciences; Biological and medical sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Generalities. Biometrics, experimentation. Remote sensing; Heating, air conditioning and ventilation; Ventilation
• ISSN: 0021-8634; 1095-9246
• DOI: 10.1006/jaer.1997.0177

A mathematical model based on energy and momentum conservation equations was experimentally validated with four wooden and perforated ventilation ducts with aperture ratios of 0·5, 1·0, 1·5, and 2·0. The model facilitated validation because of the elimination of the frictional losses achieved by equating expressions from the conservation equations of energy and momentum. The model accurately predicted the air flow distribution parameters along the full length of the perforated ventilation ducts operated under turbulent flow conditions. The regain coefficient and the energy correction factor were equal to unity, and the discharge coefficient was 0·65, along the perforated duct. The outlet air jet discharge angle varied along the entire duct length, and was directly related to the average velocity and total head inside the duct for turbulent flow.