EXTENDED SURFACE CONVECTIVE COOLING STUDIES OF ENGINE COMPONENTS USING THE TRANSIENT LIQUID-CRYSTAL TECHNIQUE

Citation
Aj. Neely et al., EXTENDED SURFACE CONVECTIVE COOLING STUDIES OF ENGINE COMPONENTS USING THE TRANSIENT LIQUID-CRYSTAL TECHNIQUE, Proceedings of the Institution of Mechanical Engineers. Part A, Journal of power and energy, 211(3), 1997, pp. 273-287
Citations number
26
Categorie Soggetti
Engineering, Mechanical
ISSN journal
09576509
Volume
211
Issue
3
Year of publication
1997
Pages
273 - 287
Database
ISI
SICI code
0957-6509(1997)211:3<273:ESCCSO>2.0.ZU;2-V
Abstract
A heat transfer tunnel used for local convective heat transfer coeffic ient measurements on liquid crystal instrumented models is described. The tunnel uses the new mesh heater device to produce a good approxima tion to a step change in the test section flow temperature. A simple a nalytical model of the cooling performance of cylindrical extended sur faces is derived from empirical relations obtained from the literature . Experiments conducted on a smooth cylinder and selected cylindrical finned geometries are discussed. In the configurations investigated, t he relative sizes of the fin diameter to the fin array greatly exceed any geometries previously reported. The use of liquid crystal mapping techniques is shown to provide the full distribution of local heat tra nsfer coefficients across the fin surface. This enables a greater unde rstanding of the convective cooling process than could be obtained fro m the simple average measurements of h previously reported in the lite rature. Existing finned tube correlations are shown to be unable to pr edict the measured heat transfer levels. The investigation shows that correct selection of fin geometry can result in a significant increase in overall convective cooling performance.