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Journal of Flow Visualization and Image Processing
SJR: 0.161 SNIP: 0.312 CiteScore™: 0.1

ISSN Druckformat: 1065-3090
ISSN Online: 1940-4336

Journal of Flow Visualization and Image Processing

DOI: 10.1615/JFlowVisImageProc.v7.i4.40
18 pages

AN EXPERIMENTAL INVESTIGATION OF NATURAL CONVECTION IN AN OPEN-ENDED HORIZONTAL ANNULUS USING A NONINTRUSIVE FULL FLOW FIELD VISUALIZATION METHOD

Minel J. Braun
Department of Mechanical Engineering, University of Akron, Akron, OH 44325
C. C. Daniels
Mechanical Engineering Department, University of Akron, Akron, OH 44325-3903
M. P. Dyko
Research and Technology, Aircraft Braking Systems Corporation, Akron, OH 44306

ABSTRAKT

The study presented in this article aims at mapping experimentally the flow patterns in the annulus between an internally heated inner cylinder and a surrounding outer cylinder with an aspect ratio of length/diameter ~1. Both cylinders are stationary. The annulus is open axially to the ambient at both ends, and natural convection ensues when the inner cylinder is heated. The experiments are performed at temperatures of 32.2 °C (90 °F) and 65.6 °C (150 °F), corresponding to Rayleigh numbers (RaL = gβL3(Ti - T /να) of 6.62 × 103 and 1.58 × 104 , respectively. This range encompasses the region in which stable laminar flow transitions to unstable laminar flow of higher intensity. The full flow field tracking (FFFT) method utilized in this study uses a coherent laser light sheet to illuminate sequential sections of the annulus, while a low-luminosity camera equipped with a long-distance microscope is coupled to a video recorder for recording the flow patterns.