Effect of Heating System Position on Vertical Distribution of Crop Temperature and Transpiration in Greenhouse Tomatoes

✍ Scribed by F.L.K. Kempkes; N.J. Van de Braak; J.C. Bakker

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 256 KB
• Volume: 75
• Category: Article
• ISSN: 0021-8634
• DOI: 10.1006/jaer.1999.0485

✦ Synopsis

Notation a, b, c distances, m A area, m B absorption factor c N speci"c heat of air, J/kg/K C carbon dioxide concentration, p.p.m d diameter heating pipes, m F view factor I leaf area index, m/m ¸characteristic length of leaves, m q radiation heat #ux, W Q A latent heat #ux density, W/m r C external leaf resistance, s/m r !-resistance factor depending on carbon dioxide concentration r J internal leaf resistance, s/m r R resistance factor depending on temperature di!erence, s/m r N resistance factor depending on saturation de"cit, s/m ¹ absolute temperature, K u air velocity, m/s X, >, Z intermediate variables p saturation de"cit, Pa convective heat exchange coe$cient, W/m/K psychrometric constant, 65)8 Pa/K emissivity density of air, kg/m Stefan}Boltzman constant, 5)67;10\ W/m/K summation i, j ,k surface number cx crop layer number