THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

Changshuang Zhi

,

Erqiang Chen

,

Shaofeng Zhang

,

Buting Zhang

,

Zhenping Li

,

Shun You

,

Yingwen Liu

online first only

Correlation development and parametric investigation for local pressure drop of mixing t-junction using response surface methodology

ABSTRACT
The behavior of mixing flow within a T-junction is highly intricate in energy transport systems. A 3D numerical model for the T-junction was established, the flow and thermal characteristics were analyzed in detail. The response surface methodology was employed to investigate the interactive effects of angle, velocity ratio, and diameter ratio on the local pressure drop coefficients of the T-junction. The corresponding correlations for KAC and KBC were developed and validated. It could be observed that, compared with the inlet pressures of the main and branch tubes, the static pressure in the downstream section of the main tube drops sharply. A symmetrical vortex can be found at the entrance of the downstream in main tube. Three key parameters including cos θ, U*, and D* all have a significant effect on KAC and KBC, and the interactions of cos θ with U* and D* are significant for KAC, while for KBC, the interactions among the three parameters are all significant. Furthermore, the developed correlations demonstrate high accuracy in predicting the local pressure drop coefficients. To validate their reliability, two additional tests are conducted. The discrepancies between the simulated and predicted values of KAC are merely 1.46% and 7.39% for the first and second tests, respectively, while those for KBC are limited to 9.7% and 7.02%, respectively.
KEYWORDS
T-junction, Mixing Characteristics, Local pressure drop, response surface methodology, correlation
PAPER SUBMITTED: 2025-07-29
PAPER REVISED: 2025-09-24
PAPER ACCEPTED: 2025-09-26
PUBLISHED ONLINE: 2025-11-08
DOI REFERENCE: https://doi.org/10.2298/TSCI250729197Z
REFERENCES
  1. Lin, C.H., et al., Investigating thermal mixing and reverse flow characteristics in a T-junction by way of experiments, Applied Thermal Engineering, 99 (2016), pp. 1171-1182
  2. Yang, B., et al., State-of-art of branching T-junction: Experiments, modeling, developing prospects and applications, Experimental Thermal and Fluid Science, 109 (2019), p. 109895
  3. Lu, T., et al., Large-eddy simulations of velocity and temperature fluctuations in hot and cold fluids mixing in a tee junction with an upstream straight or elbow main pipe, Nuclear Engineering and Design, 263 (2013), pp. 32-41
  4. Kamide, H., et al., Study on mixing behavior in a tee piping and numerical analyses for evaluation of thermal striping, Nuclear Engineering and Design, 239 (2009), 1, pp. 58-67
  5. Lee, J.I., et al., Numerical analysis of thermal striping induced high cycle thermal fatigue in a mixing tee, Nuclear Engineering and Design, 239 (2009), 5, pp. 833-839
  6. Wang, Y., et al., Experimental investigation of the thermal fluctuations in hot and cold fluids mixing in a T-junction filled with spherical particles, Applied Thermal Engineering, 71 (2014), 1, pp. 310-316
  7. Gao, K., et al., Experimental investigation and numerical simulation for weakening the thermal fluctuations in a T-junction, Annals of Nuclear Energy, 78 (2015), pp. 180-187
  8. Wang, Y., Lu, T., Influence of the particle diameter and porosity of packed porous media on the mixing of hot and cold fluids in a T-junction, International Journal of Heat and Mass Transfer, 84 (2015), pp. 680-690
  9. Guo, Z., et al., Monitoring of wall temperature fluctuations for thermal fatigue in a horizontal mixing T-junction pipe, Progress in Nuclear Energy, 104 (2018), pp. 298-305
  10. Wang, J., et al., Temperature and pressure oscillations induced by steam direct contact condensation in a T-junction with porous inner-structures, International Journal of Heat and Mass Transfer, 168 (2021), p. 120863
  11. Lu, T., et al., Numerical Simulation of Flow and Heat Transfer with Large-Eddy Simulation in a Mixing T-Junction, Applied Mechanics and Materials, 152 (2012), pp. 1319-1324
  12. Abou-Haidar, N.I.,S.L. Dixon, Pressure Losses in Combining Subsonic Flows Through Branched Ducts, Journal of Turbomachinery, 114 (1992), 1, pp. 264-270
  13. Bassett, M., et al., Calculation of steady flow pressure loss coefficients for pipe junctions, Proceedings of the institution of mechanical engineers, part C: Journal of Mechanical Engineering Science, 215 (2001), 8, pp. 861-881
  14. Schmandt, B., et al., Determination of head change coefficients for dividing and combining junctions: A method based on the second law of thermodynamics, Chemical Engineering Science, 111 (2014), pp. 191-202
  15. Herwig, H., Schmandt, B., How to Determine Losses in a Flow Field: A Paradigm Shift towards the Second Law Analysis, Entropy, 16 (2014), 6, pp. 2959-2989
  16. Pérez-García, J., et al., New coefficient to characterize energy losses in compressible flow at T-junctions, Applied Mathematical Modelling, 34 (2010), 12, pp. 4289-4305
  17. Gan, G., Riffat, S.B., Numerical determination of energy losses at duct junctions, Applied Energy, 67 (2000), 3, pp. 331-340
  18. Abdulwahhab, M., et al., Numerical prediction of pressure loss of fluid in a T-junction, International journal of energy and environment, 4 (2013), 2, pp. 253-264
  19. Patiño-Jaramillo, G.A., et al., Laminar flow and pressure loss in planar Tee joints: Numerical simulations and flow analysis, European Journal of Mechanics-B/Fluids, 92 (2022), pp. 75-89
  20. Zhi, C., et al., Numerical investigation of liquid-liquid two-phase separation and pressure drop characteristics in T-junctions, The Canadian Journal of Chemical Engineering, 100 (2022), 2, pp. 363-374
  21. Zhi, C., et al., Numerical analysis and artificial neural network-based prediction of two-phase flow pressure drop of refrigerants in T-junction, International Journal of Refrigeration, 137 (2022), pp. 34-42
  22. Wang, S.J., Mujumdar, A.S., Flow and mixing characteristics of multiple and multi-set opposing jets, Chemical Engineering and Processing: Process Intensification, 46 (2007), 8, pp. 703-712
  23. Su, B., et al., Large eddy simulation of flow and mixing characteristics in a T-junction under inflow pulsation, Applied Thermal Engineering, 181 (2020), p. 115924
  24. Lu, P., et al., Analysis of pressure drop in T-junction and its effect on thermodynamic cycle efficiency, Applied Energy, 231 (2018), pp. 468-480
  25. Patiño-Jaramillo, G.A., et al., Laminar flow and pressure loss in planar Tee joints: Pressure loss coefficients, European Journal of Mechanics - B/Fluids, 94 (2022), pp. 263-275
  26. Lei, X.-s., et al., Parametric study and optimization of dimpled tubes based on Response Surface Methodology and desirability approach, International Journal of Heat and Mass Transfer, 142 (2019), p. 118453
  27. Tang, Y., et al., Multi-objective optimization of methanol reforming reactor performance based on response surface methodology and multi-objective particle swarm optimization coupling algorithm for on-line hydrogen production, Energy Conversion and Management, 307 (2024), p. 118377
  28. Qader, B.S., et al., RSM approach for modeling and optimization of designing parameters for inclined fins of solar air heater, Renewable Energy, 136 (2019), pp. 48-68
  29. Manmai, N., et al., Bioethanol production from sunflower stalk: application of chemical and biological pretreatments by response surface methodology (RSM), Biomass Conversion and Biorefinery, 11 (2021), 5, pp. 1759-1773
PDF VERSION [DOWNLOAD]
Correlation development and parametric investigation for local pressure drop of mixing t-junction using response surface methodology