Numerical Simulation of Cross Flow in In-Line Square Tube Array to Estimate the Convective Heat Transfer Coefficient

Hossin Omar^1, , Suliman Alfarawi¹, Azeldin El-sawi¹ and Mohammed Zeo¹

¹Department of Mech. Eng. Uni. Of Benghazi, Libya

Cite this paper:
Hossin Omar, Suliman Alfarawi, Azeldin El-sawi and Mohammed Zeo. Numerical Simulation of Cross Flow in In-Line Square Tube Array to Estimate the Convective Heat Transfer Coefficient. American Journal of Energy Research. 2021; 9(2):84-91. doi: 10.12691/ajer-9-2-2

Abstract

Flow cross tube banks is an important application of different types of heat exchangers, such as compact heat exchangers, and baffled shell and tube heat exchangers. Baffles are used in shell and tube heat exchangers to allow the flow to become cross the tubes. This ensures the mix and increases the convective heat transfer coefficient. Design models of baffled shell and tube heat exchanger, which ensures the cross flow, relay on convective heat transfer coefficient. Which obtained from empirical correlation available in the literature. This work is a numerical approach to simulate flow cross a single tube and an in-line square tube array to estimate the convective heat transfer coefficient. This approach is an alternative to the experimental approach. In order to calculate the heat transfer coefficient and it’s relation to the Reynolds number for a single tube and for an in-line square tube array, a Computation Fluid Dynamic [CFD] software (ANSYS FLUENT), Which utilizes Reynolds Average Navier Stokes [RANS] method to solve the momentum equation in 3-D, was utilized to conduct the numerical simulations. Each model was simulated at 4 different entry velocities of (10, 15, 20, 25 m/s) for a Reynold’s number ranging between 6000-35000. The turbtulence model used was K-ω sst. The results obtained via the CFD simulations were validated with an empirical correlation for the two models. These results have deviations from the empirical results ranging between 5 to 22%. The numerical simulation and the empirical correlation results have identical trends for the case of a single tube and for the case of in-line square tube array. For further improvement in results validations, further studies should be made.

Keywords:
CFD: Computation Fluid Dynamic RANS: Reynolds Average Navier Stokes 3-D: three dimensional PDE: Partial Differential Equations FDM: Finite Difference Method FEM: Finite Element Method FVM: Finite Volume Method

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Figures

References:

[1]	E. Buyruk, M.W. Johnson, I. Owen, Numerical and experimental study of flow and heat transfer around a tube in cross-flow at low Reynolds number, Int. J. Heat Fluid Flow. 19 (1998).
[2]	T. Kim, Effect of longitudinal pitch on convective heat transfer in crossflow over in-line tube banks, Ann. Nucl. Energy. 57 (2013) 209-215.
[3]	Z. S. Abdel-Rehim, Heat Transfer and Turbulent Fluid Flow Over a Staggered Circular Tube Bank. Mechanical Engineering Department, National Research Center, Dokki, Giza, Egypt, 2014.
[4]	Nabeel Abeda and Imran Afgan, A CFD study of flow quantities and heat transfer by changing a vertical to diameter ratio and horizontal to diameter ratio in inline tube banks using URANS turbulence models. Institute of Anbar, Middle Technical University, Iraq (2017).
[5]	A. Bender, A.M. Meier, M. Vaz, P.S.B. Zdanski, A numerical study of forced convection in a new trapezoidal tube bank arrangement, Int. Commun. Heat Mass Transf. 91 (2018) 117-124.
[6]	Peter D Souza, Deepankar Biswas, Suresh. Deshmukh, Air side performance of tube bank of an evaporator in a window airconditioner by CFD simulation with different circular tubes with uniform transverse pitch variation, Department of Mechanical Engineering, Veermata Jijabai Technological Institute, Mumbai, India 2020.
[7]	Bergman, T., Lavine, A., Incropera, F. and Dewitt, D. (2011). Fundamentals of Heat and Mass Transfer. 7th Edition, John Wiley and Sons, Jefferson City.
[8]	A. Zukauskas, Heat transfer from tubes in crossflow, Adv. Heat Transf. 18 (1987) 87-159.
[9]	H. Versteeg, (1996), An Introduction to Computational Fluid Dynamics: The Finite Volume Method Approach, Longman House, Burnt Mill, Harlow.
[10]	Zena K. Kadhim, Muna S. Kassim, Adel Y. Abdul Hassan, Effect of Integral Finned Tube on Heat Transfer Characteristics for Cross Flow Heat Exchanger, International Journal of Computer Applications, Volume 139 – No.3, April 2016.
[11]	Priyanka G, M. R. Nagraj, CFD Analysis of Shell and Tube Heat Exchanger With and Without Fins, International Journal of Science and Research, (2012).