International Scientific Journal


Adopting enhanced tube is an effective way to enhance the performance of a shell-and-tube heat exchanger. In this paper, a drop-shaped tube with stream¬lined cross-section was used to enhance heat transfer of the torsional flow heat exchanger. The characteristics of the fluid-flow and heat transfer in torsional flow heat exchanger with drop-shaped tube were studied numerically, considering three kinds of axis ratios (a/b=1.5, 1.8, 2) of the tube. The reliability of numerical results was verified through experimental results. The results indicate that the wake size of the streamlined drop-shaped tube is smaller than that of the conventional smooth tube, and the drop-shaped tube reduces the flow dead zone in torsional flow heat exchanger. As the axis ratio of a/b increases, the shell side Nusselt number and comprehensive performance increase, due to enhancement of the turbulence kinetic energy of the transition section. When the axis ratio is 2, the Nusselt number is increased by 12.44-18.99%, and the comprehensiveness is increased by 13.27-19.2%, compared with the torsional flow heat exchanger with the smooth tube. The quantitative analysis of the velocity indicates that the relative magnitude and proportion of transverse velocity components of fluid are important factors affecting the thermal-hydraulic performance of torsional flow heat exchanger.
PAPER REVISED: 2021-08-28
PAPER ACCEPTED: 2021-09-08
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2022, VOLUME 26, ISSUE Issue 5, PAGES [3689 - 3702]
  1. Zeyninejad Movassag, S. , et al., Tube bundle replacement for segmental and helical shell and tube heat exchangers: Performance comparison and fouling investigation on the shell side, Applied Thermal Engineering, 51 (2013), 1 - 2, pp. 1162 - 1169
  2. Dong, Q.W., et al., Numerical and experimental investigation of shellside characteristics for RODbaffle heat exchanger, Applied Thermal Engineering, 28 (2008), 7, pp. 651-660
  3. Peng, B., et al., An Experimental Study of Shell-and-Tube Heat Exchangers With Continuous Helical Baffles, Journal of Heat Transfer, 129 (2007), pp. 1425-1431
  4. Jian, W., et al., Numerical investigation on baffle configuration improvement of the heat exchanger with helical baffles, Energy Conversion and Management, 89 (2015), pp. 438-448
  5. Gu, X., et al., Contrast experiment al research on heat transfer and flow resistance performance for tree kinds of shell-and-tube heat exchangers, China Mechanical Engineering, 23 (2011), pp. 1611-1615
  6. Lei, Y., et al., Design and performance analysis of the novel shell-and-tube heat exchangers with louver baffles, Applied Thermal Engineering, 125 (2017), pp. 870-879
  7. Gu, X., et al., Characteristics of Fluid Flow and Heat Transfer in the Shell Side of the Trapezoidal-like Tilted Baffles Heat Exchanger, Journal of Thermal Science, 27 (2018), 6, pp. 602-610
  8. Gu, X., et al., Analysis of flow dead zone in shell side of a heat exchanger with torsional flow in shell side, Applied Thermal Engineering, 180 (2020),
  9. Gu, X., et al., Multi-objective optimization on structural parameters of torsional flow heat exchanger, Applied Thermal Engineering, 161 (2019),
  10. Wang, W., et al., Numerical investigation of tube-side fully developed turbulent flow and heat transfer in outward corrugated tubes, International Journal of Heat and Mass Transfer, 116 (2018), pp. 115-126
  11. Gradziel, S., et al., Experimental determination of the heat transfer coefficient in internally rifled tubes, Thermal Science, 23 (2019), Suppl. 4, pp. 1163-1174
  12. Selvaraj, P., et al., Computational fluid dynamics analysis on heat transfer and friction factor characteristics of a turbulent flow for internally grooved tubes, Thermal Science, 17 (2013), 4, pp. 1125-1137
  13. Pongsoi, P., et al., Heat transfer and flow characteristics of spiral fin-and-tube heat exchanger s: A review, International Journal of Heat and Mass Transfer, 79 (2014), pp. 417-431
  14. Yagita, T., et al., Formability Improvement by Die-bearing Grooves in Tube Extrusion with Spiral Inner Projections, Procedia Engineering, 81 (2014), pp. 641-646
  15. Dogan, S., et al., Numerical comparison of thermal and hydraulic performances for heat exchangers having circular and elliptic cross-section, International Journal of Heat and Mass Transfer, 145 (2019),
  16. Hasan, A.,K. Sirén, Performance investigation of plain circular and oval tube evaporatively cooled heat exchangers, Applied Thermal Engineering, 24 (2004), 5-6, pp. 777-790
  17. He, S., et al., Heat and mass transfer performance of wet air flowing around circular and elliptic tube in plate fin heat exchangers for air cooling, Heat and Mass Transfer, 55 (2019), 12, pp. 3661-3673
  18. Gharbi, N.E., et al., Numerical optimization of heat exchangers with circular and non-circular shapes, Case Studies in Thermal Engineering, 6 (2015), pp. 194-203
  19. Wang, Q., et al., Analysis on thermal hydraulic performance of the elliptical tube in the finned-tube heat exchanger by new method, International Journal of Heat and Mass Transfer, 134 (2019), pp. 388-397
  20. Akbari, M., et al., Experimental investigation of the heat transfer for non-circular tubes in a turbulent air cross flow, Experimental Heat Transfer, (2020), pp. 1-18
  21. Ibrahim, T.A.,A. Gomaa, Thermal performance criteria of elliptic tube bundle in crossflow, International Journal of Thermal Sciences, 4 8 (2009), 11, pp. 2148-2158
  22. Bayat, H., et al., Experimental study of thermal - hydraulic performance of cam-shaped tube bundle with staggered arrangement, Energy Conversion and Management, 85 (2014), pp. 470-476
  23. Mirabdolah Lavasani, A., et al., Experimental study of convective heat transfer from in-line cam shaped tube bank in crossflow, Applied Thermal Engineering, 65 (2014), 1-2, pp. 85-93
  24. Abolfathi, S., et al., Experimental study on flow around a tube in mixed tube bundles comprising cam-shaped and circular cylinders in in-line arrangement, International Journal of Thermal Sciences, 163 (2021),
  25. Lavasani, A.M., et al., Effect of blockage ratio on pressure drag and heat transfer of a cam-shaped tube, Heat and Mass Transfer, 52 (2015), 9, pp. 1935-1942
  26. Mobedi, P., et al., The aspect ratio effect on the performance of a cam-shaped cylinder in crossflow of air, Experimental Heat Transfer, (2021),
  27. Park, H.-C., et al., Numerical Study for Heat Transfer Characteristics Varying Cross-Sectional Shape of a Tube, Korean Journal of Air-Conditioning and Refrigeration Engineering, 24 (2012), 7, pp. 560-566
  28. He, Z., et al., Numerical investigation on performance comparison of non-Newtonian fluid flow in vertical heat exchangers combined helical baffle with elliptic and circular tubes, Applied Thermal Engineering, 100 (2016), pp. 84-97
  29. Du, T., et al., Performance of continuous helical baffled heat exchanger with varying elliptical tube layouts, International Journal of Heat and Mass Transfer, 133 (2019), pp. 1165-1175
  30. Wang, Y., et al., Characteristics of heat transfer for tube banks in crossflow and its relation with that in shell-and-tube heat exchangers, International Journal of Heat and Mass Transfer, 93 (2016), pp. 58 4-594

© 2022 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence