Experimental Investigation of Natural Convection in Partitioned Enclosures

Abstract

Natural convection heat transfer within a two-dimensional, partitioned enclosure of aspect ratio 1 was investigated experimentally using a Mach-Zehnder interferometer. The vertical walls were maintained isothermal at different temperatures, while the horizontal walls and the partitions were insulated. Local and average heat-transfer coefficients were determined for the air and carbon dioxide filled enclosures both with and without partitions for Grashof numbers between 1.7×105 and 3.0×106. Good agreement was found between the results in the present study for the nonpartitioned enclosure and those previously published. The partitions were found to significantly influence the convective heat transfer. Observations of the interferometric fringes indicated that the core region is unsteady, with the unsteadiness occasionally affecting the flow along the vertical isothermal walls, beginning at Grashof numbers as low as 5×105.

Internal baffles to reduce the natural convection in the voids of hollow blocks

“…Dividing the enclosure by a partition hanging from the ceiling or extending from the floor or both was studied by many researchers both experimentally (Lauriat and Desrayaud 2006;Aviram et al 2001;Gebhart et al 1988;Nansteel and Greif 1981;Nansteel and Greif 1984;Olson et al 1990;Chen et al 1990;Warrington and Ameel 1995;Bajorek and Lloyd 1982) and theoretically (Vasic et al 1991;Williams and Baker 1994;Hanjalic et al 1996;Zimmerman and Acharya 1987;Tong and Gerner 1986;Bilgen 2002). Bajorek and Lloyd (1982) presented an experimental study for natural convection in empty and baffled square enclosures.…”

“…Inserting a flow obstacle to alter the convection currents in the cavities was proposed as a means to change the rate of heat transfer across enclosures (Mezrhab et al 2006;Bilgen 2005;da Silva and Gosselin 2005;Lauriat and Desrayaud 2006;Aviram et al 2001;Gebhart et al 1988;Nansteel and Greif 1981;Nansteel and Greif 1984;Olson et al 1990;Chen et al 1990;Warrington and Ameel 1995;Vasic et al 1991;Williams and Baker 1994;Hanjalic et al 1996;Bajorek and Lloyd 1982). Mezrhab et al (2006) studied the natural convection and radiation heat transfer in a cavity having a square body at its center.…”

“…Bajorek and Lloyd (1982) presented an experimental study for natural convection in empty and baffled square enclosures. Two different fluids, air and carbon dioxide, have been used to fill the cavities.…”

Wärmeübergang bei freier Konvektion in seitlich beheizten Rechteckbehältern

“…Man erkennt, dab im Vergleich zum Mittelwert die Beziehungen yon Elder [8] und von Newell und Schmidt [21] zu groBe und diejengen yon Thielemann [29], Meyer et al [30], Shiralkar und Tien [19] zu kleine Werte liefern k6nnen. Die Beziehung von Bajorek und Lloyd [31] liefert grunds/itzlich zu kleine Werte. Tabelle 1.…”

Natural convection and entropy generation in a square cavity

“…Natural convection in closed cavities has been studied previously (Bajorek and Lloyd, 1982;Jetli et al, 1986;and Chang and Tsai, 1997) but many of them were concentrated on the fluid behaviour in the cavity. Analytical and numerical studies of natural convection in enclosures was carried out by Vosseur et al (1994).…”