Turbulent natural convection cooling of electronic components mounted on a vertical channel

The turbulence natural convection boundary layer inside a infinite vertical channel with differentially heated walls is analyzed based on a similarity solution methodology. The differences between mean temperature and velocity profiles in a boundary layer along a vertical flat plate and in a channel flow, make it necessary to introduce new sets of scaling parameters. In the limit as H* → ∞, two distinctive parts are considered: an outer region which dominates the core of the flow and inner constant heat flux region close to the walls. The proper inner scaling velocity is showed to be determined by the outer parameters due to momentum integral. The theory is contrasted with the one suggested by George & Capp (1), the deficiencies of which are identified.

Download Full-text

Use of a vibrating plate to enhance natural convection cooling of a discrete heat source in a vertical channel

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2007.01.023 ◽

2007 ◽

Vol 27 (13) ◽

pp. 2276-2293 ◽

Cited By ~ 32

Author(s):

L.A. Florio ◽

A. Harnoy

Keyword(s):

Natural Convection ◽

Heat Source ◽

Vertical Channel ◽

Discrete Heat Source ◽

Convection Cooling ◽

Vibrating Plate

Download Full-text

An Experimental Study of Natural Convection Cooling of an Array of Heated Protrusions in a Vertical Channel in Water

Journal of Electronic Packaging ◽

10.1115/1.3226506 ◽

1989 ◽

Vol 111 (1) ◽

pp. 33-40 ◽

Cited By ~ 9

Author(s):

Y. Joshi ◽

T. Willson ◽

S. J. Hazard

Keyword(s):

Heat Transfer ◽

Natural Convection ◽

Power Dissipation ◽

Three Dimensional ◽

Vertical Channel ◽

Steady Flows ◽

Transfer Rates ◽

Fluid Velocities ◽

Convection Cooling ◽

Flow Visualizations

An experimental investigation of steady state and transient natural convection from a column of eight in-line rectangular heated protrusions in a vertical channel in water is presented. Flow visualizations and element surface temperature measurements were carried out for several power dissipation levels in the range of 0.2–1.5 W per component and channel spacings from 6.4 to 23 mm. The three-dimensional steady flows were visualized in two mutually perpendicular planes. Average component temperatures determined from the measurements on the five fluid exposed faces were used to obtain nondimensional heat transfer rates. Heat transfer data for all channel spacings except the smallest did not differ from the measurements for an isolated surface by more than 14 percent. For the smallest spacing, the component surface temperatures increased significantly due to a reduction in the fluid velocities. Measurements and flow visualizations during the transient indicated an initial diffusive transport period, followed by the evolution of convective effects. No overshoots in component temperatures were found. Steady transport responses with selectively powered components are also examined.

Download Full-text