Experimental and Numerical Investigation of Cylindrical and Shaped Cooling Holes With Forward and Reverse Injection

Abstract

The present work proposes a suitable injection hole configuration of cylinder and laidback fan-shaped with forward and reverse direction for film cooling of a gas turbine blades application, based on experimental and numerical analysis. The experimental study is conducted for cylindrical hole at blowing ratio (1), injection angle (35°), and density ratio (1.2). The numerical study is performed for a wide range of operating parameters such as blowing ratios on (1-3), density ratios (2.42), mainstream flow Reynolds number as 4000 based on the hydraulic diameter of wind tunnel channel and, injection angle (35°) with the effect of forward and reverse injection of laidback fan shaped. The present study reveals that the formation of kidney vortices mitigated for reverse-shaped holes (secondary air is injected such that its axial velocity component is in the reverse direction to that of the mainstream) results in higher cooling performance with respect to forward-shaped holes. The coolant coverage is likewise more consistent and higher in the lateral direction compared to the forward injection.

Acknowledgements

The authors are thankful to Science and Technology (SERB), New Delhi under Core Research Grand; Project Ref. No. CRG/2021/001213; for the experimental and computational facility to carry out the present study in the Department of Mechanical Engineering at NIT Manipur, India.

Disclosure statement

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

Additional information

Notes on contributors

Raj Gaurav

Raj Gaurav is a research scholar in the Department of Mechanical Engineering at National Institute of Technology Manipur, Imphal West – Manipur, India. He obtained his Bachelor of Technology in Mechanical Engineering from National Institute of Technology Manipur, India in the year 2019. His topic of research is mist film cooling.

Ashutosh Kumar Singh

Ashutosh Kumar Singh is a Assistant Professor in the Department of Mechanical Engineering at NIT Manipur. He received his bachelor’s degree in mechanical engineering with University Gold-Medal in academics from Giani Zail Singh PTU Campus Bathinda Punjab in 2015 and selected by MHRD for NIT-IIT Trainee Teacher Scheme in 2016. He did master’s degree in mechanical engineering (Specialization: Fluids and Thermal Engineering) from Indian Institute of Technology Guwahati, Assam, 2018. Completed his Ph.D. from Department of Mechanical Engineering, Indian Institute of Technology, Guwahati, Assam.

Kuldeep Singh

Kuldeep Singh is currently working in the Rolls Royce’s University Technological Center in “Gas Turbine and Transmission Research Center (G2TRC), University of Nottingham, United Kingdom as a senior researcher. He has worked with the diverse team of international researchers. He is a Gold Medalist in B.Tech. He did M.Tech. and Ph.D. from IIT Delhi. He was Post-Doctoral Fellow in University of Beira Interior, Portugal. He is recipient of prestigious INSPIRE Faculty Award in 2017 from DST. He has worked on numerous projects sponsored by DRDO, DST, BHEL, Portuguese Foundation of Science and Technology, European Union, and RR.

Dushyant Singh

Dushyant Singh is an Associate Professor in the Department of Mechanical Engineering at Dr. B. R. Ambedkar National Institute of Technology Jalandhar, Punjab- India. He finished his Ph.D. 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 had been a faculty member in the Department of Mechanical Engineering at National Institute of Technology Manipur, India. His research interests include experimental and computational fluid flow – heat transfer, turbulence, and two-phase heat transfer enhancement.