NUMERICAL INVESTIGATION OF HEAT TRANSFER USING IMPINGING JETS ON TRIANGULAR AND SQUARE RIBBED ROUGHENED WALLS

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Çalışır T., Çalışkan S., Kilic M., Baskaya Ş.

ISI BILIMI VE TEKNIGI DERGISI-JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY, vol.37, no.1, pp.13-24, 2017 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 37 Issue: 1
  • Publication Date: 2017
  • Journal Name: ISI BILIMI VE TEKNIGI DERGISI-JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.13-24
  • Keywords: Impinging jet, Heat transfer, Rib, CFD, IN-LINE ARRAYS, 2 OPPOSITE DIRECTIONS, SPENT AIR-FLOW, CIRCULAR JETS, TURBULENCE MODELS, STREAMWISE PITCH, NUMBER, SURFACE, RIBS
  • Open Archive Collection: AVESIS Open Access Collection
  • Gazi University Affiliated: Yes

Abstract

This paper presents a heat removal study on triangular and square ribbed surfaces under an array of impinging air jets. The investigation was carried out using nozzles with a 7x3 rectangular array of circular jets. The effect of Re number, jet-to-plate distance, and rib arrangement on heat transfer and fluid flow characteristics was examined numerically. Two arrangements have been studied. Arrangement A considers the situation when the cooling jets are directed towards the ribs, while arrangement B considers the situation when the jets are directed towards the centre line of the cavity between two ribs. Wall jets of neighboring jets have a stronger interaction with increasing Reynolds number. The lowest and highest local heat transfer for all rib geometries was obtained for H/d=8 and H/d=4-6, respectively. On triangular ribbed surfaces the stagnation point Nusselt number values for arrangement A are significantly higher than the stagnation point Nusselt numbers for arrangement B.