Session: 07-04-02: Fluid Structure Interaction / Marine Electromechanical Systems and Ocean Mechatronics

Paper Number: 95139

95139 - Effects of Flow-Induced Vibration on Forced Convection Heat Transfer From Three Tandem Cylinders at Different Spacing Ratios 

Flow-induced vibration (FIV) of the tandem cylinders is ubiquitous in scientific studies and industrial applications. FIV of tandem cylinders has been featured strongly in the engineering and scientific research community due to the nonlinear interferences of the wake from cylinders. The understanding of FIV on tandem cylinders remains a practical problem in nuclear power plant, chemical processing, oil and gas industry, food and pharmaceutical industries, etc. The most common phenomena are FIV on the heat exchanger tubes due to vortex shedding. FIV on two tandem cylinders has been investigated extensively in the previous literature. However, FIV on multiple tandem cylinders cannot be predicted solely from the understandings of FIV on two tandem cylinders. Indeed, the underlying flow dynamics for FIV on multiple tandem cylinders remains to be explored. The dynamic response of FIV on three tandem cylinders differs from that of two tandem cylinders as the downstream cylinder maximum oscillation increases. Furthermore, the FIV on tandem cylinders is widely studied in the literature for hydrodynamic and aerodynamic aspects, with much less attention to heat transfer. In fact, the heat transfer characteristics due to FIV on tandem cylinders are widely neglected.

This work numerically investigates the effect of FIV on heat transfer performance of three heated tandem cylinders at different spacing ratios and reduced velocity. The flow is considered incompressible, two-dimensional, laminar and the simulation is performed at Reynolds number Re=100, Prandtl number Pr=0.7. The three elastically mounted heated cylinders are allowed to oscillate in the transverse direction with reduced velocity U_r=2-20, mass ratio m*=2, and zero damping coefficient for maximum oscillation. The finite volume method is employed to solve the continuity, momentum and energy equations using commercial software ANSYS Fluent. The motion of the cylinder is implemented via a User-defined function (UDF) within a Fluent environment. The dynamic mesh method is employed for the cylinder’s movement and adaptation of the mesh close to the boundary of the cylinder. The numerical methodology used in the present work accurately captures the flow around elastically mounted tandem cylinders.

The spacing ratio between cylinders G*=2, 4 and 6 are considered to elucidate the effect of FIV on heat transfer in extended body regime (G*=2), reattachment regime (G*=4) and co-shedding regime (G*=6). The effect of the spacing ratio on FIV and heat transfer is observed through flow structures and quantified through oscillation amplitude, shedding frequency, pressure coefficient and Nusselt number. The flow around the cylinders and the associated heat transfer depends strongly on the spacing ratio. The present findings can be utilized to develop strategy for reducing fouling, removing contaminant and wax in piggyback pipes used in nuclear power plants or offshore-oil extraction.  

Keywords: Flow-induced vibration, Tandem cylinder, spacing ratio, reduced velocity, multiple cylinder, forced convection, heat transfer.

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

Presenting Author Biography: DR. Islam is currently an associate Professor of Mechanical Engineering Department at Khalifa University of Science and Technology. His current research is focused on the effect of FIV on Tandem cylinders.

Authors:

Hamid Khan Khalifa University of Science and Technology
Md. Islam Khalifa University of Science & Technology