Session: K6-06: HEAT TRANSFER IN ENERGY SYSTEM - COMPONENTS I

Paper Number: 131116

131116 - Flow and Heat Transfer Characteristics in Arrays of Stationary and Elastically Supported Cylinders 

Abstract: 

The flow-induced vibrations (FIV) and heat transfer in arrays of cylinders have physical significance in many engineering fields, including aerospace, automotive, and chemical engineering. Wake interference and vortices shedding can cause the FIV phenomenon in arrays of cylinders in cross flow scenarios. This vibration can cause fatigue failure in the cylinders if not considered in the design. On the other hand, heat transfer through these arrays of cylinders can play an important role in many applications, such as in heat exchangers. The Nusselt number and mean pressure coefficient on the cylinder wall are essential parameters that need to be studied to optimize the performance of such systems. Understanding the complex interaction between FIV and heat transfer is essential to design heat exchangers where cylinder arrays are used. This numerical study compares the flow and heat transfer characteristics in 3×3 arrays of stationary and elastically supported cylinders. This study considers a 3×3 arrays of nine circular heated cylinders with inline arrangements. 2-D numerical simulations considering low Reynolds number and forced convection heat transfer are carried out using ANSYS Fluent loaded with user-defined function (UDF). User-defined function (UDF) governs cylinders’ movements or displacements in y-directions for elastically supported cylinders. In this study, several parameters are considered, including a reduced velocity range of 2-14, a fixed centre-to-centre distance between cylinders of 3D, a Reynolds number of 100, a Prandtl number of 0.7, and a constant mass ratio of 2. This study investigates the effect of FIV on flow patterns, mean pressure coefficient, hydrodynamic forces, and Nusselt Number in arrays of elastically supported cylinders. The results are then compared with arrays of cylinders with stationary cylinders to understand the significance of FIV. The results of this study indicate that the flow pattern for arrays of elastically supported cylinders depends on the reduced velocity, and it is different from that of arrays of stationary cylinders. At lower reduced velocities, it follows the same pattern as stationary cylinders. Additionally, it is observed that FIV in elastically supported cylinders shows a significant improvement in the average Nusselt number for arrays of elastically supported cylinders when compared to arrays of stationary cylinders. The results of this study can be utilized to optimize the performance of heat exchagners considering arrays of cylinders by minimizing the FIV and enhancing the heat transfer.

Keywords: Arrays of cylinders; Wake interference; Vorticity; Mean pressure coefficient; Nusselt number; CFD;

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

Presenting Author Biography: Dr. Md. Islam is currently an Associate Professor of Mechanical 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:

Sanjeev Kumar Khalifa University of Science and Technology
Md. Islam Khalifa University of Science & Technology
Yap Fatt Khalifa University of Science and Technology
Isam Janajreh Khalifa University of Science and Technology