# NUMERICAL INVESTIGATION ON THE CONVECTIVE HEAT TRANSFER IN A SPIRAL COIL WITH RADIANT HEATING

## Main Article Content

## Abstract

The objective of this study was to numerically investigate the heat transfer in spiral coil tube in the laminar, transitional, and turbulent flow regimes. The Archimedean spiral coil was exposed to radiant heating and should represent heat absorber of parabolic dish solar concentrator. Specific boundary conditions represent the uniqueness of this study, since the heat flux upon the tube external surfaces varies not only in the circumferential direction, but also in the axial direction. The curvature ratio of spiral coil varies from 0.029 at the flow inlet to 0.234 at the flow outlet, while the heat transfer fluid is water. The 3-D steady-state transport equations were solved using the Reynolds stress turbulence model. Results showed that secondary flows strongly affect the flow and that the heat transfer is strongly asymmetric, with higher values near the outer wall of spiral. Although overall turbulence levels were lower than in a straight pipe, heat transfer rates were larger due to the curvature-induced modifications of the mean flow and temperature fields.

## Article Details

**Thermal Science**, [S.l.], v. 20, p. S1215-S1226, feb. 2017. ISSN 2334-7163. Available at: <http://thermal-science.tech/journal/index.php/thsci/article/view/1644>. Date accessed: 17 oct. 2017. doi: https://doi.org/10.2298/TSCI16S5215D.

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Accepted 2017-02-07

Published 2017-02-07

## References

[2] Dean, W. R., The Stream-Line Motion of Fluid in a Curved Pipe, Philosophical Magazine, 5 (1928), 30, pp. 673-695

[3] Naphon, P., Suwagrai, J., Effect of Curvature Ratios on the Heat Transfer and Flow Developments in the Horizontal Spirally Coiled Tubes, International Journal of Heat and Mass Transfer, 50 (2007), 3, pp. 444-451

[4] Balakrishnan, Ret al., Heat Transfer Correlation for a Refrigerant Mixture in a Vertical Helical Coil Evaporator, Thermal Science, 13 (2009), 4, pp. 197-206

[5] Rajavel, R., Saravanan, K., Heat Transfer Studies on Spiral Plate Heat Exchanger, Thermal Science, 12 (2008), 3, pp. 85-90

[6] Naphon, P., Study on the Heat Transfer and Flow Characteristics in a Spiral-Coil Tube, International Communications in Heat and Mass Transfer, 38 (2011), 1, pp. 69-74

[7] Khan, M. K., et al., Experimental Investigation on Diabatic Flow of R-134a through Spiral Capillary Tube, International Journal of Refrigeration, 32 (2009), 2, pp. 261-271

[8] Naphon, P., Wongwises, S., An Experimental Study on the In-Tube Convective Heat Transfer Coefficients in a Spiral Coil Heat Exchanger, International Communications in Heat and Mass Transfer, 29 (2002), 6, pp. 797-809

[9] Ho, J. C., Wijeysundera, N. E., Study of Compact Spiral-Coil Cooling and Dehumidifying Heat Exchanger, Applied Thermal Engineering, 16 (1996), 10, pp. 777-790

[10] Ho, J. C., Wijeysundera, N. E., An Unmixed-Air Flow Model of a Spiral Coil Cooling Dehumidifying Unit, Applied Thermal Engineering, 19 (1999), 8, pp. 865-883

[11] Nakayama, A., et al., Conjugate Numerical Model for Cooling a Fluid Flowing through a Spiral Coil Immersed in a Chilled Water Container, Numerical Heat Transfer, Part A, 37 (2000), 2, pp. 155-165

[12] Kurnia, J. C., et al., Numerical Investigation of Laminar Heat Transfer Performance of Various Cooling Channel Designs, Applied Thermal Engineering, 31 (2011), 6, pp. 1293-1304

[13] Alammar, K. N., Turbulent Flow and Heat Transfer Characteristics in U-Tubes: A Numerical Study, Thermal Science, 13 (2009), 4, pp. 175-181

[14] Yang, R., Chiang, F. P., An Experimental Heat Transfer Study for Periodically Varying-Curvature Curved-Pipe, International Journal of Heat and Mass Transfer, 45 (2002), 15, pp. 3199-3204

[15] Sasmito, A. P., et al., Numerical Evaluation of Laminar Heat Transfer Enhancement in Nanofluid Flow in Coiled Square Tubes, Nanoscale Research Letters, 6 (2011), 1, pp. 376-385

[16] Sasmito, A. P., et al., Numerical Analysis of Laminar Heat Transfer Performance of In-plane Spiral Ducts with Various Cross-Sections at Fixed Cross-Section Area, International Journal of Heat and Mass Transfer, 55 (2012), 21, pp. 5882-5890

[17] Vashisth, S., et al., A Review on the Potential Applications of Curved Geometries in Process Industry, Industrial and Engineering Chemistry Research, 47 (2008), 10, pp. 3291-3337

[18] Morton, B. R., Laminar Convection in Uniformly Heated Horizontal Pipes at Low Rayleigh Numbers, Quarterly Journal of Mechanics and Applied Mathematics, 12 (1959), 4, pp. 410-420

[19] Mori, Y., et al., Forced Convective Heat Transfer in Uniformly Heated Horizontal Tubes, International Journal of Heat and Mass Transfer, 9 (1965), 5, pp. 453-463

[20] Djordjević, M., et al., Numerical Analyses of the Radiant Heat Flux Produced by Quartz Heating System, Proceedings, The 3rd International Conference Mechanical Engineering in XXI Century, Nis, Serbia, 2015, pp. 75-80

[21] Patankar, S. V., Numerical Heat Transfer and Fluid Flow, Taylor & Francis, New York, USA, 1980

[22] Kays, W., et al., Convective Heat and Mass Transport, 4th ed., MacGraw Hill, Singapore, 2005

[23] ***, IAPWS Industrial Formulation for the Thermodynamic Properties of Water and Steam (IAPWS- IF97), The IAPWS-IF97, 2007

[24] Ali, S., Seshadri, C., Pressure Drop in Archimedean Spiral Tubes, Industrial and Engineering Chemistry Process Design and Development, 10 (1971), 3, pp. 328-332

[25] Piazza, I. Di, Ciofalo, M., Numerical Prediction of Turbulent Flow and Heat Transfer in Helically Coiled Pipes, International Journal of Thermal Sciences, 49 (2010), 4, pp. 653-663

[26] ***, ANSYS FLUENT Theory Guide, Release 15.0, ANSYS Inc., Canonsburg, Penn., USA, 2013

[27] ***, ANSYS FLUENT User's Guide, Release 15.0, ANSYS Inc., Canonsburg, Penn., USA, 2013

[28] Gnielinski, V., Heat Transfer and Pressure Drop in Helically Coiled Tubes, Proceedings, The 8th International Heat Transfer Conference, Vol. 6, Tayler and Francis, Washington, DC, 1986, pp. 2847-2854

[29] Seban, R. A., McLaughlin, E. F., Heat Transfer in Tube Coils with Laminar Turbulent Flow, International Journal of Heat and Mass Transfer, 6 (1963), 5, pp. 387-395

[30] Lin, C. X., Ebadian, M. A., Developing Turbulent Convective Heat Transfer in Helical Pipes, International Journal of Heat and Mass Transfer, 40 (1997), 16, pp. 3861-3873