Session: K20-03: APPLICATIONS OF COMPUTATIONAL HEAT TRANSFER I

Paper Number: 131114

131114 - Two-Degrees of Freedom Flow-Induced Vibrations and Heat Transfer of Twin Cylinders in Tandem and Staggered Arrangements 

Abstract: 

This work explores the impact of cylinder configurations on flow-induced oscillations and heat transfer in laminar regime at a Reynolds number of 100. Both cylinders were allowed to oscillate in two-degrees of freedom, experiencing motion both along the flow direction (streamwise) and transverse to it. The configuration of the two identical circular cylinders was varied from tandem alignment (α = 0°) to staggered (α = 30° and 60°). The spacing between the two cylinders remained at 6D, with D representing the cylinder's diameter. The cylinders were heated at a constant temperature to observe the heat transfer characteristics influenced by the two-dimensional flow-induced vibrations (FIV). The cylinders' mass ratio and damping ratio were specified as 5 and 0.02, respectively. To investigate the FIV, the reduced velocity (Ur) was systematically adjusted within the range of 2 to 10. The findings revealed the responsiveness of the cylinders to variations in reduced velocity and cylinder configurations, particularly with regard to vibrations and heat transfer. The tandem alignment resulted in most pronounced vibrational responses in both cylinders. In this configuration, the downstream cylinder (D_C) experienced decreased drag compared to the upstream cylinder (U_C), while the staggered configuration resulted in higher drag for D_C. Both cylinders exhibited lock-in behavior within the range of Ur = 6 to 8, with significant transverse vibration amplitudes. D_C experienced the widest span of lock-in phenomena in the tandem configuration. Streamwise vibrations were insignificant when compared to their transverse counterparts. Different vorticity patterns emerged in the wake of the cylinders, due to the different configurations. The staggered setup with α = 60° lead to a substantial 75% reduction in transverse vibrations and a 9% enhancement in the averaged Nusselt number for D_C compared to the tandem configuration.

Keywords: Flow-induced vibrations; Heat Transfer; Streamwise and transverse oscillations; Forced convection; Vorticity

Presenting Author: Md. Islam Khalifa University of Science & Technology

Presenting Author Biography: Dr. Md. Islam is currently an Associate Professor of Mechanical and Nuclear Engineering at Khalifa University of Science and Technology. He received his MSc and PhD from University of the Ryukyus, Okinawa Japan in 2004 and 2007, respectively. He has 19 years of university teaching experience and taught different undergraduate and graduate courses. His main research interest is focused in the area of energy and heat transfer enhancement, extended surfaces, heat exchangers, heat pipes, vortex generators, flow induced vibrations(FIV), fluid surface interactions(FSI), fouling of heat exchangers in the oil and gas industry, CSP technologies, solar powered Stirling engine generator, solar desalination technologies, refrigeration and air-conditioning systems, atmospheric water collection etc. During his academic career, Dr. Islam contributed in a book chapter and published more than 100 research papers in Journals and International conferences, including Applied Energy, Applied Thermal Engineering, International journal of Heat and Mass transfer, International journal of Mechanical sciences, Renewable Energy, Physics of Fluids, Ocean Engineering, International Journal of Thermal sciences. Dr. Islam is the recipient of ADNOC R&D Wisdom Book Award (2012), Japan Govt. Scholarship (Monbukagakusho) Award (2002-2004) and Heiwa Nakajima Foundation (HNF) Tokyo, Japan Scholarship Award (2005-2007). He was the organizing committee member of the Second International ENERGY 2030 Conference, Abu Dhabi, and chaired sessions of GT India ASME 2019 Gas Turbine India Conference, Heat Transfer, Fluid Mechanics and Thermodynamics (HEFAT) International Conference (2016, 2017), ICOPE-2013 China, ADRAC R&D 2013 Conference, Abu Dhabi. He is the current member of ASME and IEB

Authors:

Ussama Ali Khalifa University of Science and Technology
Md. Islam Khalifa University of Science & Technology
Isam Janajreh Khalifa University of Science and Technology