Effect of pulse jet frequency on impingement heat transfer

Rozli Zulkifli, E. Benard, S. Raghunathan, A. Linton

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

An experimental investigation was carried out to study the effect of flow pulsation frequency on the local and average heat transfer characteristics of a heated air jet. The experiments were performed for steady jets and for pulsating jets at frequencies from 10 to 80 Hz. The nozzle to plate spacing, x/D was fixed at 4 and Reynolds number was set at 16 000, 23 300 and 32 000. The duty cycle of the pulse airflow was 33%. Pulsation of the air jet was produced by a rotating cylinder valve mechanism. The investigation showed that the average pulsed jet Nusselt number was equal or higher than the steady jet Nusselt number at the same Reynolds number for all values of frequencies except at 50Hz. In contrast, the stagnation point heat transfer of the pulsed jet was lower than that of steady jets for all the frequencies tested. The higher average Nusselt numbers for pulse flow compared to steady flow resulted from significant enhancement of the heat transfer at distances greater than about 1 nozzle diameter away from the stagnation point. This increase is believed to be caused by enhanced turbulence intensity due to pulsing the jet. The degradation in lieat transfer at the stagnation point is believed to be due to the small turbulent intensity at this position.

Original languageEnglish
Title of host publicationAIAA Paper
Pages10983-10992
Number of pages10
Publication statusPublished - 2004
Externally publishedYes
Event42nd AIAA Aerospace Sciences Meeting and Exhibit - Reno, NV
Duration: 5 Jan 20048 Jan 2004

Other

Other42nd AIAA Aerospace Sciences Meeting and Exhibit
CityReno, NV
Period5/1/048/1/04

Fingerprint

Heat transfer
Nusselt number
Nozzles
Reynolds number
Steady flow
Air
Turbulence
Degradation
Experiments

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Zulkifli, R., Benard, E., Raghunathan, S., & Linton, A. (2004). Effect of pulse jet frequency on impingement heat transfer. In AIAA Paper (pp. 10983-10992)

Effect of pulse jet frequency on impingement heat transfer. / Zulkifli, Rozli; Benard, E.; Raghunathan, S.; Linton, A.

AIAA Paper. 2004. p. 10983-10992.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Zulkifli, R, Benard, E, Raghunathan, S & Linton, A 2004, Effect of pulse jet frequency on impingement heat transfer. in AIAA Paper. pp. 10983-10992, 42nd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, 5/1/04.
Zulkifli R, Benard E, Raghunathan S, Linton A. Effect of pulse jet frequency on impingement heat transfer. In AIAA Paper. 2004. p. 10983-10992
Zulkifli, Rozli ; Benard, E. ; Raghunathan, S. ; Linton, A. / Effect of pulse jet frequency on impingement heat transfer. AIAA Paper. 2004. pp. 10983-10992
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