TY - JOUR T1 - The Effect of Inlet Baffle on the Skin Friction Coefficient and Turbulence Intensity in an Air-Cooled Channel AU - Nguyen Thanh, Luan AU - Nguyen, M. P. AU - Nguyen, M. H. AU - Le, H. S. N. AU - Lai, N. H. PY - 2025 DA - December Y2 - 2025 DO - 10.5541/ijot.1739149 JF - International Journal of Thermodynamics PB - Uluslararası Uygulamalı Termodinamik Derneği İktisadi İşletmesi WT - DergiPark SN - 1301-9724 SP - 243 EP - 249 VL - 28 IS - 4 LA - en AB - This study addresses the impact of an inlet baffle mounted opposite a hot surface on the properties of turbulence and flow resistance in an air-cooled channel. This study focuses on analyzing the variation in the skin friction coefficient and air turbulence intensity along the hot surface. The influence of an inclined baffle angle α = 15−60° and relative baffle length Ln = 0.625−0.875 under the Reynolds number spectrum Re = 4000−16000 was considered. Results indicated that turbulence intensity increased when the Reynolds number increased, the baffle length increased, or the inclined baffle angle decreased. The skin friction coefficient increased when the Reynolds number decreased, the baffle length increased, or the inclined baffle angle decreased. The maximum heat transfer rate occurs at α = 15°, Ln = 0.875, and Re = 16000, and vice versa at α = 60°, Ln = 0.625, and Re = 4000. In comparing the lowest and highest heat transfer configurations, the skin friction coefficient decreased by 77.9 %, and turbulence intensity decreased by 97 %. This means that heat transfer can be increased at the cost of higher pump power. The results of this study contribute to a more comprehensive understanding of the effect of an inlet baffle on fluid chaotic motion and flow resistance, as well as the mechanism that leads to the variation in heat transfer ability and pressure loss in the channel under the impact of the inlet baffle. KW - Inlet baffle KW - Air-cooled channel KW - Skin friction coefficient KW - Turbulence intensity CR - E. Guersoy, M. Gürdal, E. Gedik, K. Arslan, and A. Dağdeviren, "Experimental and numerical study on ferrohydrodynamic and magneto-convection of Fe3O4/water ferrofluid in a sudden expansion tube with dimpled fins," Journal of the Taiwan Institute of Chemical Engineers, vol. 164, Nov. 2024, Art. no. 105676, doi: 10.1016/j.jtice.2024.105676. CR - T. Alam and M.-H. Kim, "A comprehensive review on single phase heat transfer enhancement techniques in heat exchanger applications," Renewable and Sustainable Energy Reviews, vol. 81, pp. 813-839, Jan. 2018, doi: 10.1016/j.rser.2017.08.060. CR - L. N. Thanh and M. H. Nguyen, "Heat transfer and flow characteristics in horizontal spiral coils with flat tubes and rectangular ribs: CFD and optimization," International Journal of Thermofluids, vol. 26, Mar. 2025, Art. no. 101072, doi: 10.1016/j.ijft.2025.101072. CR - M. Yilmaz, "The effect of inlet flow baffles on heat transfer," International Communications in Heat and Mass Transfer, vol. 30, no. 8, pp. 1169-1178, Nov. 2003, doi: 10.1016/S0735-1933(03)00182-9. CR - Y. Menni, A. Azzi, and C. Zidani, "CFD simulation of thermo-aeraulic fields in a channel with multiple baffle plates," Journal of Thermal Engineering, vol. 4, no. 6, pp. 2481-2495, Sep. 2018, doi: 10.18186/thermal.465696. CR - H. Ameur, "Effect of the baffle inclination on the flow and thermal fields in channel heat exchangers," Results in Engineering, vol. 3, Sep. 2019, Art. no. 100021, doi: 10.1016/j.rineng.2019.100021. CR - P. Promvonge et al., "Characterization of heat transfer and artificial neural networks prediction on overall performance index of a channel installed with arc-shaped baffle turbulators," Case Studies in Thermal Engineering, vol. 26, Aug. 2021, Art. no. 101067, doi: 10.1016/j.csite.2021.101067. CR - N. Thanh Luan and N. Minh Phu, "Thermohydraulic Performance and Entropy Generation of Baffled Channel: Numerical Analysis and Optimization," Journal of Thermophysics and Heat Transfer, vol. 36, no. 2, pp. 303-313, Apr. 2022, doi: 10.2514/1.T6332. CR - S. Saha, P. Biswas, S. Nath, and L. Singh, "Numerical simulations of Newtonian fluid flow through a suddenly contracted rectangular channel with two different types of baffle plates," Soft Computing, vol. 25, no. 15, pp. 9873-9885, Aug. 2021, doi: 10.1007/s00500-020-05326-4. CR - J. E. Salhi, S. S. Mousavi Ajarostaghi, T. Zarrouk, M. Saffari Pour, N. Salhi, and M. Salhi, "Turbulence and thermo‐flow behavior of air in a rectangular channel with partially inclined baffles," Energy Science & Engineering, vol. 10, no. 9, pp. 3540-3558, Sep. 2022, doi: 10.1002/ese3.1239. CR - Y. Menni, G. Lorenzini, R. Kumar, B. Mosavati, and S. Nekoonam, "Aerodynamic Fields inside S‐Shaped Baffled‐Channel Air‐Heat Exchangers," Mathematical Problems in Engineering, vol. 2021, pp. 1-11, May 2021, doi: 10.1155/2021/6648403. CR - A. Boonloi and W. Jedsadaratanachai, "Effects of baffle height and baffle location on heat transfer and flow profiles in a baffled duct: a CFD analysis," Modelling and Simulation in Engineering, vol. 2022, pp. 1-19, Jul. 2022, doi: 10.1155/2022/3698887. CR - Y. Menni, A. Azzi, and A. Chamkha, "Enhancement of convective heat transfer in smooth air channels with wall-mounted obstacles in the flow path: a review," Journal of Thermal Analysis and Calorimetry, vol. 135, no. 4, pp. 1951-1976, Feb. 2019, doi: 10.1007/s10973-018-7268-x. CR - S. Sripattanapipat and P. Promvonge, "Numerical analysis of laminar heat transfer in a channel with diamond-shaped baffles," International Communications in Heat and Mass Transfer, vol. 36, no. 1, pp. 32-38, Jan. 2009, doi: 10.1016/j.icheatmasstransfer.2008.09.008. CR - Y.-T. Yang and C.-Z. Hwang, "Calculation of turbulent flow and heat transfer in a porous-baffled channel," International Journal of Heat and Mass Transfer, vol. 46, no. 5, pp. 771-780, Feb. 2003, doi: 10.1016/S0017-9310(02)00360-5. CR - R. Shaheed, A. Mohammadian, and H. Kheirkhah Gildeh, "A comparison of standard k–ε and realizable k–ε turbulence models in curved and confluent channels," Environmental Fluid Mechanics, vol. 19, no. 2, pp. 543-568, Apr. 2019, doi: 10.1007/s10652-018-9637-1. CR - O. Ghoulam, H. Talbi, K. Amghar, A.-i. Amrani, A. Charef, and I. Driouich, "Heat transfer improvement in turbulent flow using detached obstacles in heat exchanger duct," International Journal of Thermofluids, vol. 27, May 2025, Art. no. 101225, doi: 10.1016/j.ijft.2025.101225. CR - L. N. Thanh, "The influence of baffled channel for cooling hot surface: Numerical simulation and Taguchi analysis," Case Studies in Thermal Engineering, vol. 52, Dec. 2023, Art. no. 103646, doi: 10.1016/j.csite.2023.103646. CR - Ansys Fluent Theory Guide 12.0, ANSYS Inc.,, Canonsburg, PA, USA, 2012. CR - S. Rana, H. B. Dura, S. Bhattraı, and R. Shrestha, "Impact of baffle on forced convection heat transfer of CuO/water nanofluid in a micro-scale backward facing step channel," Journal of Thermal Engineering, vol. 8, no. 3, pp. 310-322, May 2022, doi: 10.18186/thermal.1107168. UR - https://doi.org/10.5541/ijot.1739149 L1 - https://dergipark.org.tr/en/download/article-file/5041249 ER -