Journal of Technology in Aerospace Engineering

Journal of Technology in Aerospace Engineering

Investigating the Impact of Turbulators and Impinging Jets on Heat Transfer and Pressure Drop in Annular Heat Exchangers

Document Type : Research Article

Authors
1 Aerospace Engineering, Aerial Structures, Faculty of Mechanics, Ahrar University, Rasht ,Iran
2 Aerospace Engineering ,Faculty of Aerospace, Semnan University, Semnan, Iran
Abstract
This study examines the effects of helical turbulators and impinging jet cooling systems on heat transfer performance and pressure drop in annular heat exchangers. Key design variables-including blockage ratio, helix angle, and turbulator geometry-were evaluated. Computational simulations using STAR-CCM+ software were employed to validate the results against experimental benchmarks. The findings demonstrate that increasing the blockage ratio and decreasing the pitch notably improve the Nusselt number, albeit at the cost of a higher pressure drop. Square turbulators achieved an average 15% higher Nusselt number than circular ones but incurred approximately 20% greater pressure losses. The influence of impinging jet cooling was further investigated across two distinct geometries, revealing that jet configuration and crossflow interactions significantly affect thermal performance. Among the configurations, Sample B-with a greater number of jets and a more uniform heat transfer distribution (evidenced by a 10% lower temperature standard deviation)-exhibited superior cooling characteristics relative to Sample A. These findings underscore the critical role of impinging-jet integration in enhancing heat exchanger performance by elevating heat transfer rates and controlling pressure drop. Moreover, results confirm that combining square turbulators with impinging jets can substantially improve exchanger efficiency in industrial systems. The outcomes offer practical insights for developing energy-efficient heat exchangers with reduced operational costs and extended service life. The study also identifies opportunities for future investigations into hybrid cooling strategies incorporating advanced materials and structural modifications for high-temperature thermal applications.
Keywords
Subjects

[1] J. Han and S. Dutta, "Internal convection heat transfer and cooling: An experimental approach," Lecture Series-van Kareman Institute for Fluid Dynamics, vol. 5, pp. C1-C147, 1995.
[2] C. V. M. Braga and F. E. M. Saboya, "Turbulent heat transfer, pressure drop and fin efficiency in annular regions with continuous longitudinal rectangular fins," Experimental Thermal and Fluid Science, vol. 20, no. 2, pp. 55-65, 1999, https://doi.org/10.1016/S0894-1777(99)00026-6.
[3] J. Hossain et al., "Use of rib turbulators to enhance postimpingement heat transfer for curved surface," Journal of Engineering for Gas Turbines and Power, vol. 139, no. 7, 2017, Art. no. 071901, https://doi.org/10.1115/1.4035659.
[4] A. M. E. Momin, J. Saini, and S. Solanki, "Heat transfer and friction in solar air heater duct with V-shaped rib roughness on absorber plate," International Journal of Heat and Mass Transfer, vol. 45, no. 16, pp. 3396-3383, 2002, https://doi.org/10.1016/S0017-9310(02)00046-7.
[5] L. Al-Hadhrami, T. Griffith, and J. C. Han, "Heat transfer in two-pass rotating rectangular channels (AR= 2) with five different orientations of 45deg V-shaped rib turbulators," International Journal of Heat and Mass Transfer, vol. 125, no. 2, pp. 232-242, 2003, https://doi.org/10.1115/1.1561455.
[6] W. Kays and E. Leung, "Heat transfer in annular passages-hydrodynamically developed turbulent flow with arbitrarily prescribed heat flux," International Journal of Heat and Mass Transfer, vol. 6, no. 7, pp.557-537, 1963, https://doi.org/10.1016/0017-9310(63)90012-7.
[7] J. Dirker and J. P. Meyer, "Convective heat transfer coefficients in concentric annuli," Heat Transfer Engineering, vol. 26, no. 2, pp. 38-44, 2005, https://doi.org/10.1080/01457630590897097.
[8] V. Gnielinski, "Heat transfer coefficients for turbulent flow in concentric annular ducts," Heat Transfer Engineering, vol. 30, no. 6, pp. 431-436, 2009, https://doi.org/10.1080/01457630802528661
[9] L. Florschuetz, D. Metzger, D. Takeuchi, and R. Berry, "Multiple jet impingement heat transfer characteristic-experimental investigation of in-line and staggered arrays with crossflow," 1980.
[10] W. Qiuwang, L. Mei, and Z. Min, "Effect of blocked core-tube diameter on heat transfer performance of internally longitudinal finned tubes," Heat Transfer Engineering, vol. 29, no. 1, pp. 107-115, 2008, https://doi.org/10.1080/09647040701677672.
[11] P. Zamankhan, "Heat transfer in counterflow heat exchangers with helical turbulators," Communications in Nonlinear Science and Numerical Simulation, vol. 15, no. 10, pp. 2894-2907, 2010, https://doi.org/10.1016/j.cnsns.2009.10.025.
[12] M. Peric, "Flow simulation using control volumes of arbitrary polyhedral shape," ERCOFTAC Bulletin, vol. 62, pp. 25-29, 2004, https://doi.org/10.1016/0045-7930(88)90024-2.
[13] C. Cornaro, A. S. Fleischer, M. Rounds, and R. J. Goldstein, "Jet impingement cooling of a convex semi-cylindrical surface," International Journal of Thermal Sciences, vol. 40, no. 10, pp. 890-898, 2001, https://doi.org/10.1016/S1290-0729(01)01275-3.
[14] F. Menter and C. Rumsey, "Assessment of two-equation turbulence models for transonic flows," in Fluid Dynamics Conference, 1994, Paper 2343, https://doi.org/10.2514/6.1994-2343.
[15] W. M. Malalasekera and E. James, "Calculation of radiative heat transfer in three-dimensional complex geometries," American Society of Mechanical Engineers, New York, United States, 1995.
[16] T. Liu, J. P. Sullivan, K. Asai, C. Klein, and Y. Egami, Pressure and Temperature Sensitive Paints, Springer, 2005.
[17] P. A. Durbin, "Separated flow computations with the k-epsilon-v-squared model," AIAA Journal, vol. 33, no. 4, pp. 659-664, 1995, https://doi.org/10.2514/3.12628.
[18] N. Zuckerman and N. Lior, "Jet impingement heat transfer-physics, correlations, and numerical modeling," Advances in Heat Transfer, vol. 39, pp. 565-631, 2006, https://doi.org/10.1016/S0065-2717(06)39006-5.
[19] L. Florschuetz, D. E. Metzger, and C. Truman, "Jet array impingement with crossflow-correlation of streamwise resolved flow and heat transfer distributions," 1981.
[20] R. S. Figliola and D. E. Beasley, "Theory and design for mechanical measurements," Measurement Science and Technology, vol. 12, no. 10, 2001, Art. no. 1743, https://doi.org/10.1088/0957-0233/12/10/701.
[21] L. Florschuetz, D. Metzger, and C. Su, "Heat transfer characteristics for jet array impingement with initial crossflow," Journal of Heat Transfer, vol. 106, no. 1, pp. 34-41, 1984, https://doi.org/10.1115/1.3246656.
[22] S. Y. Waware, S. S. Kore, and S. P. Patil, "Heat transfer enhancement in tubular heat exchanger with jet impingement-a review," Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, vol. 101, no. 2, pp. 8-25, 2023, https://doi.org/10.37934/arfmts.101.2.825.
[23] A. S. Kurhade et al., "Investigating the effect of heat transfer influenced by the application of wavy corrugated twisted tape inserts in double pipe heat exchangers," Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, vol. 122, no. 2, pp. 146-155, 2024, https://doi.org/10.37934/arfmts.122.2.146155.
[24] S. S. Kore, M. K. Chaudhary, P. S. Bhambare, and D. K. Kaithari, "The heat transfer and fluid flow investigations of single dimple with straight and curved arch turbulator within in a duct," Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, vol. 115, no. 1, pp. 206-216, 2024, https://doi.org/10.37934/arfmts.115.1.206216.
 

  • Receive Date 23 November 2024
  • Revise Date 30 March 2025
  • Accept Date 20 April 2025
  • First Publish Date 07 May 2025