ABSTRACT
The present work focuses on the experimental and large-eddy simulation (LES) investigation of fluid flow and heat transfer due to the impingement of an unconfined turbulent slot jet on a smooth flat plate. Three LES sub-grid scale models are validated with the experimental observations for first time in terms effect of slot widths. A detailed parametric study is conducted considering nozzle to plate spacing ratio from 4 to 12, non-dimensional slot width from 0.015 to 0.035, and Reynolds number range from 4000 to 12000. The results show an appreciable change in the stagnation point and along the wall jet Nusselt numbers with the change in Reynolds number, nozzle-to-plate spacing and non-dimensional slot width. No significant effect of nozzle to plate spacing is observed along the wall jet Nusselt number beyond the streamwise location at 0.2. The local Nusselt number increases with an increase in Reynolds number while it decreases with an increase in nondimensional slot width. Comparison of various LES sub-grid models with RANS (k-ω SST) turbulence model is performed. The results show that turbulent kinetic energy plays a major role in enhancing the heat transfer rate. Dissipation of the turbulent kinetic energy increases with an increase in nozzle to plate spacing and non-dimensional slot width. Further, a correlation is proposed for the stagnation point and wall jet region Nusselt numbers in terms of effect of slots width, Reynolds number and non-dimensional nozzle to plate spacing.
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Acknowledgments
This present study work is grateful to the Department of Science and Technology (SERB), New Delhi-India of Project (Ref. No. ECR/2016/001364) for using the computational and experimental setup facility to carry out LES and experimental studies in the Department of Mechanical Engineering, NIT Manipur-India.
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No potential conflict of interest was reported by the author(s).
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Notes on contributors
Dushyant Singh
Dushyant Singh did his bachelor’s degree in mechanical engineering and master’s degree in specialization of mechanical engineering: Computational Fluid Dynamics and Heat Transfer. He finished his doctorate’s degree in mechanical engineering from Indian Institute Technology, Delhi in 2014. He was postdoctoral researcher in joint research industrial project work with BHEL industry in IIT Delhi. He has been a faculty member in the Department of Mechanical Engineering at National Institute of Technology Manipur-India, since 2015. His research interests include experimental and computational fluid flow – heat transfer, turbulence and two-phase heat transfer enhancement. He has authored more than 50 international journal and conference.
Udayraj
Udayraj is an Assistant Professor in the Department of Mechanical Engineering at the Indian Institute of Technology Bhilai, India. He received his Ph.D. degree from the Indian Institute of Technology Delhi in 2017. He has worked with the Institute of Textile & Clothing, The Hong Kong Polytechnic University, Hong Kong, as a postdoctoral fellow. His research areas are computational fluid dynamics, heat transfer through thermal protective fabric, thermal comfort and building heat transfer. He has authored more than 40 international journal and conference papers.
Ashutosh Narayan Singh
Ashutosh Narayan Singh is a master’s degree program Thermal and Fluids Engineering student in the Department of Mechanical Engineering at National Institute of Technology Manipur, India. He obtained his Bachelor’s in Engineering from IMS Engineering Collage Uttar Pradesh, India. His topic of research is computational heat transfer.
Jishnu Handique
Jishnu Handique was a project associate in the Department of Mechanical Engineering at IIT Bhilai. He also worked as a Junior Research Fellow in the Department of Ocean Engineering and Naval Architecture at IIT Kharagpur. He pursued his graduation in Thermal & Fluids Engineering from NIT Manipur, India. His primary research interests are CFD and Numerical Heat Transfer.