Numerical studies on enhanced thermal management of outdoor enclosures using natural convection in open channels on external walls

In many applications, switching/signal processing electronics equipment is commonly placed in outdoor enclosures. These enclosures, being outdoors, receive full solar irradiation, creating an extra heat load that must be handled. Although most enclosures are sufficiently large to allow for active cooling systems, smaller enclosures must meet thermal requirements by passive means only, thus imposing unique restrictions. One way to effect such requirements is to use natural convection means. The focus of this paper is to present results on computational investigations where natural convection flows were studied to optimize (by enhancing heating or cooling rates through the walls) the thermal management of small telecommunications/electronics enclosures. These enclosures were modeled as square enclosures (cavities). The numerical simulations were conducted using ICEPAK^TM , a finite-element CFD software by FDI. In this study, open, multiply-attached, channels of various cross-section and orientation were placed on two outside walls of square enclosures, with the remaining four walls left insulated. A constant heat flux load was applied to one side of the box, and heat was allowed to leave through the other uninsulated wall. Runs were carried out at different power levels and channels of various cross-section. Results indicate that the addition of channels to the square enclosure substantially reduces the amount of heat transferred into the box depending on the type of channel