Affiliations: School of Mechanical and Production Engineering,
Nanyang Technological University, Nanyang Avenue, Singapore 639798, Republic of
Singapore
Abstract: Experiments on thermal visualization of transient natural convection
from short vertical rectangular fins were conducted using the technique of
laser holographic interferometry. A sequence of infinite-fringe interferograms
recorded for the heating regime of an aluminum fin demonstrates the effect of
fin base heating on local convection coefficients and reveals alternating and
oscillatory buoyancy-driven flows similar to those over the top surface of
heated horizontal plates. The effect of fin base heating results in greater
uniformity of the local heat transfer coefficient along the fin. It also
significantly reduces the steady-state heat transfer coefficients of short
vertical fins compared to their transient values. Hence, the use of
steady-state solutions for the design of short vertical fins operating in
transient conditions may not introduce as much error as was previously
thought.