Experimental analysis of local and average heat transfer between circular impinging jet and flat plate

ABSTRACT

Heat transfer over a heated plate positioned normal to the horizontal circular impinging jet is investigated experimentally. The area average and local heat transfer characteristics over a large plate impinged by jet of air are investigated for Reynolds numbers ranging from 10,000 to 45,000, with jet-to-plate distances of 3–20 d for a maximum range of 0 ≤ r/d ≤ 44. The experiment is carried out for two jet diameters of 5.88 mm and 11.5 mm on a plate of 600 × 300 mm² impinged by a jet. The infrared (IR) thermal imaging method is used to find the temperature distribution over the heated plate. The combined heat transfer investigation of both local and area average gives a proper insight of the cooling phenomenon of the jet at any location over the plate. The investigation is effective in identifying areas with a greater rate of heat transfer. At various locations, the Nusselt number growth with increasing mass flow rate is studied. The area average heat transfer is discovered to be the highest at z/d = 3 for all Reynolds numbers in the A1 (0 < r/d < 2.17) region. However, for z/d = 6 and r/d = 0, the local Nusselt number is reported to be the highest. Reduction in area average heat transfer is reported in area A3, i.e., r/d = 6.5, and beyond this area, the profile of Nusselt number practically converges.

KEYWORDS:

• Air jet impingement
• heat transfer
• circular jet
• thermal imaging technique
• local heat transfer

Acknowledgments

Authors are thankful to Mr. Arvind Kumar and Mr. Bikash Pattanayak for their in the experiments and fabrication of experimental set-up.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Nomenclature

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Additional information

Funding

This work was supported by the SEED Grant under grant number I/SEED/HK/20180020.

Notes on contributors

Laxmikant Dhruw

Laxmikant Dhruw is currently pursuing Ph.D. in the Department of Mechanical Engineering at the Indian Institute of Technology Jodhpur. His research domain is Jet Impingement heat transfer.

Hardik B. Kothadia

Hardik Kothadia is an Assistant Professor in the Department of Mechanical Engineering at the Indian Institute of Technology Jodhpur. He received his Ph.D. from the Indian Institute of Technology Bombay. His fields of interest are heat transfer and fluid dynamics. He is working on thermal performance testing of different thermofluids equipment of the macro/microscale.

Arun Kumar R

Arun Kumar R is an Assistant Professor in the Department of Mechanical Engineering at the Indian Institute of Technology Jodhpur. He received his Ph.D. from the Indian Institute of Technology Madras. His fields of interest are High-Speed Flows, Shock and Blast Waves, Fluidic Actuators, Supersonic Mixing Enhancement, and Micro-Propulsion.