THERMAL SCIENCE

International Scientific Journal

Ali A. Al Mubarak

,

Syed M. Shaahid

,

Luai M. Al-Hadhrami

HEAT TRANSFER IN A CHANNEL WITH INCLINED TARGET SURFACE COOLED BY SINGLE ARRAY OF CENTERED IMPINGING JETS

ABSTRACT
An experimental investigation has been carried out to study the heat transfer characteristics in a channel with heated target plate inclined at an angle cooled by single array of equally spaced centered impinging jets for three different jet Reynolds numbers (Re=9300, 14400 and 18800). Air ejected from an array of orifices impinges on the heated target surface The target plate forms the leading edge of a gas turbine blade cooled by jet impingement technique. The work includes the effect of jet Reynolds numbers and feed channel aspect ratios (H/d = 5, 7, 9 where H=2.5, 3.5, 4.5 cm and d=0.5 cm) on the heat transfer characteristics for a given orifice jet plate configuration with equally spaced centered holes with outflow exiting in both directions (with inclined heated target surface). In general, It has been observed that, H/d=9 gives the maximum heat transfer over the entire length of the target surface as compared to all feed channel aspect ratios. H/d=9 gives 3% more heat transfer from the target surface as compared to H/d=5 (for Re=14400). Also, it has been observed that the magnitude of the averaged local Nusselt number increases with an increase in the jet Reynolds number for all the feed channel aspect ratios studied.
KEYWORDS
jet impingement, Reynolds number, nusselt number, gas turbine
PAPER SUBMITTED: 2011-06-30
PAPER REVISED: 2011-12-28
PAPER ACCEPTED: 2012-01-06
DOI REFERENCE: https://doi.org/10.2298/TSCI110630010A
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2013, VOLUME 17, ISSUE Issue 4, PAGES [1195 - 1206]
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Heat transfer in a channel with inclined target surface cooled by single array of centered impinging jets

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