Accession Number : ADA140696

Title :   Flow Visualization Study of Natural Convection from a Heated Protrusion in a Liquid Filled Rectangular Enclosure.

Descriptive Note : Master's thesis,


Personal Author(s) : Knock,R H

Full Text :

Report Date : Dec 1983

Pagination or Media Count : 70

Abstract : A flow visualization study of natural convection in a liquid filled rectangular enclosure with a small heater protruding into it from one vertical wall was conducted. The top and bottom horizontal surfaces of the enclosure were heat exchangers whose temperatures could be varied independently. The fluid in the enclosure was water. The Baker electrochemical technique which utilizes a pH indicator was used for flow visualization. Photographs were taken of the two dimensional flow for three different locations of the heater on the vertical wall. Nusselt numbers for each heater location and for a range of Rayleigh numbers were also determined. Visual results indicate the presence of a dual-cell configuration within the enclosure. There is a buoyancy driven upper cell and a shear driven lower cell. The flow of the upper cell follows the geometry of the enclosure. Though the uncertainty inherent in the experiment was high data calculations suggest a trend that as the heater is raised within the enclosure the Nusselt number decreases. (Author)

Descriptors :   *Flow visualization , *Convection(Heat transfer) , *Liquid cooling , *Printed circuit boards , Microelectronics , Closed cycle systems , Rectangular bodies , Heaters , Heat exchangers , Water , Electrochemistry , pH factor , Indicators , Photography , Two dimensional flow , Position(Location) , Walls , Numbers , Cells , Configurations , Theses

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE