Investigation of Thermal Hydraulic Performance of Wavy Double Forward Facing Step

Abstract:

This paper presents a numerical investigation to evaluate thermal-hydraulic performance of double forward facing step. The combined analysis of double forward-facing step geometries and wavy-wall amplitude, which has never been done previously, is what makes this study groundbreaking. With the help of the double-step construction and the undulating upper wall, this special arrangement seeks to improve the thermal-hydraulic performance.The effect of varying wavy amplitude and the relative double step height was evaluated under different turbulent flow conditions. The turbulent flow and energy was modelled by contiuity full Navier-Stockesand energy equations. The effect of turbulent was modelled by k- Ɛ model. The finite volume method based on a simple algorithm was adoped to the discretise the flow and energy models. ANSYS Fluent was used to obtain the target results. The obtained results show that the increasing the amplitude value and the relative step height has a noticeable effect on intensification of average Nusselt number and overall performance with a moderate increase in friction losses. The findings reported that the steps height ratio (H_r= 2.6) provides the best overall performance for all the tested Reynolds numbers.The maximum performance was 1.63 (163%) at Re=10000 for Am=0.03 m.

• Periodical: International Journal of Engineering Research in Africa (Volume 79)
• Pages: 83-97
• DOI: https://doi.org/10.4028/p-JPevr6
• Online since: June 2026
• Authors: Khudheyer S. Mushatet, Sara Rabeea Nashee, Ali K. Abdul Razzaq*
• Keywords: CFD, Forward Facing Step, Heat Transfer, Turbulent Flow, Wavy Wall

References

[1] Fahad, Mostafa Kamal, et al. Numerical investigation of the hydrothermal performance of novel vortex generators in a rectangular channel by employing inclination and rotational angles. International Journal of Thermofluids 20 (2023): 100500.‏

DOI: 10.1016/j.ijft.2023.100500

[2] Deshmukh, Prashant Wasudeo, and Subhash Lahane. Numerical evaluation of novel curved rib turbulators for thermal performance improvement in circular geometries. Heat Transfer Engineering 45.6 (2024): 528-551.‏

DOI: 10.1080/01457632.2023.2199537

[3] Mushatet, Khudheyer S., H. M. Hmood. Numerical investigation for heat transfer enhancement in a triangular twisted tube. ARPN Journal of Engineering and Applied Sciences 16.5 (2021): 593-599.‏

[4] Khan, Mohammad Nadeem. Nanofluid and perforated twisted tape integration for enhancing heat transfer in double-tube heat exchangers. Journal of Thermal Analysis and Calorimetry (2025): 1-13.‏

DOI: 10.1007/s10973-025-14423-1

[5] Kanna, Parthasarathy Rajesh, et al. "Numerical Investigation of Flow and Heat Transfer from Twin Circular Cylinders Present in Double Forward-Facing Step." Fluids 10.2 (2025): 48.‏

DOI: 10.3390/fluids10020048

[6] Venkatesh, Goveraiahgari, Meenakshi Reddy, Reddygari and Rao, Pabbisetty Mallikarjuna. Improving thermal performance of turbine blade with combination of circular and oblong fins in a wedge channel: a numerical investigation International Journal of Turbo & Jet-Engines, 2024.

DOI: 10.1515/tjj-2024-0010

[7] Thondavadi, Amogh Ashwin, et al. "Numerical Investigation of Bluff Body Shapes and Position to Enhance Heat Transfer in Double Forward-Facing Step Flow." Results in Engineering (2025): 105028.‏

DOI: 10.1016/j.rineng.2025.105028

[8] Mushatet, Khudheyer S., Farah Kh Youssif. Modeling whirling motion and heat transfer intensification in a heated tube with a twin twisted tape. 2018 International Conference on Advance of Sustainable Engineering and its Application (ICASEA). IEEE, 2018.‏

DOI: 10.1109/icasea.2018.8370984

[9] Cui, Zihao, et al. "Optical fiber anomaly detection using channel power tilt through forward and inverse calculation of ISRS." 2025 Optical Fiber Communications Conference and Exhibition (OFC). IEEE, 2025.‏

DOI: 10.1364/ofc.2025.m2c.7

[10] Rahman, Md, A., Hasnain, SMM., Pandey, S., Tapalova, A., Akylbekov, N., Rustem Zairov, R., 2024. Review on Nanofluids: Preparation, Properties, Stability, and Thermal Performance Augmentation in Heat Transfer Applications. Vol 9(30), ACS Omega.

DOI: 10.1021/acsomega.4c03279

[11] Majmader, Fawaz Bukht, Md Jahid Hasan. Multi-objective hydrothermal performance optimization of a microchannel heat sink equipped with delta winglet vortex generators using NSGA-II genetic algorithm. International Journal of Thermal Sciences 201 (2024): 109046.‏

DOI: 10.1016/j.ijthermalsci.2024.109046

[12] Yashwanth, S., et al. "Numerical investigations of fluid flow and heat transfer in double forward facing step in the presence of a fin." Numerical Heat Transfer, Part A: Applications 86.23 (2025): 8334-8356.‏

DOI: 10.1080/10407782.2024.2359051

[13] Mohankumar, Vishnu, and K. Arul Prakash. "Effect of axis ratio and geometric location of the elliptical obstacles on thermo-fluid dynamic characteristics in a double forward-facing step channel." International Journal of Numerical Methods for Heat & Fluid Flow (2025).‏

DOI: 10.1108/hff-02-2025-0087

[14] Zhang, E., Wang, T., & Chen, L. Turbulent momentum and kinetic energy transfer of channel flow over 3D wavy walls. Physical Review Fluids, 2024.

DOI: 10.1103/physrevfluids.9.034602

[15] Kumari, A., Kumar, R., & Patel, S. Enhancement of heat transfer by flowing turbulent jet on a wavy surface. Experimental Thermal and Fluid Science, 2023.

[16] Yashwanth, S., Anbalagan, S., & Arumugam, S. Numerical investigations of fluid flow and heat transfer in double forward-facing step in the presence of a fin. Numerical Heat Transfer, Part A: Applications, vol. 86, no. 7, p.897–913, 2024.

DOI: 10.1080/10407782.2024.2359051

[17] AAbu-Mulaweh HI, Armaly BF, Chen TS. Measurements in buoyancy-opposing laminar flow over a vertical forward-facing step. International Journal of Heat Mass Transfer 1996;39:1805-1813.

DOI: 10.1016/0017-9310(95)00278-2

[18] Blackburn, Hugh Maurice, Dwight Barkley, and Spencer J. Sherwin. Convective instability and transient growth in flow over a backward-facing step. Journal of Fluid Mechanics 603 (2008): 271-304.‏

DOI: 10.1017/s0022112008001109

[19] Nie, J. H., and B. F. Armaly. Reverse flow regions in three-dimensional backward-facing step flow. International journal of heat and mass transfer 47.22 (2004): 4713-4720.‏

DOI: 10.1016/j.ijheatmasstransfer.2004.05.027

[20] Sherry, Michael, D. Lo Jacono, and John Sheridan. An experimental investigation of the recirculation zone formed downstream of a forward facing step. Journal of Wind Engineering and Industrial Aerodynamics 98.12 (2010): 888-894.‏

DOI: 10.1016/j.jweia.2010.09.003

[21] Li, Z.Y., Guo, S., Bai, H.L., Gao, N. (2019). Combined flow and heat transfer measurements of backward facing step flows under periodic perturbation. International Journal of Heat and Mass Transfer, 130: 240-251.

DOI: 10.1016/j.ijheatmasstransfer.2018.10.077

[22] Vogel, J. (1985). Combined heat transfer and fluid dynamic measurements downstream of a b.

[23] Chen, Y.T., Nie, J.H., Armaly, B.F., Hsieh, H.T. Turbulent separated convection flow adjacent to backward-facing step-effects of step height. International Journal of Heat and Mass Transfer, 49(19-20): (2006), 3670- 3680.

DOI: 10.1016/j.ijheatmasstransfer.2006.02.024

[24] Amiri, A., Arzani, H.K., Kazi, S.N., Chew, B.T., Badarudin, A. (2016). Backward-facing step heat transfer of the turbulent regime for functionalized graphene nanoplatelets based water-ethylene glycol nanofluids. International Journal of Heat and Mass Transfer, 97: 538-546.

DOI: 10.1016/j.ijheatmasstransfer.2016.02.042

[25] Mittal, R., Madanan, U., Goldstein, R.J. (2017). The heat/mass transfer analogy for a backward facing step. International Journal of Heat and Mass Transfer, 113: 411-422.

DOI: 10.1016/j.ijheatmasstransfer.2017.05.087

[26] Hilo, A.K., Iborra, A.A., Sultan, M.T.H., Hamid, M.F.A. (2020). Experimental study of nanofluids flow and heat transfer over a backward-facing step channel. Powder Technology, 372: 497-505.

DOI: 10.1016/j.powtec.2020.06.013

[27] Rahman, M. A. (2024). Thermal hydraulic performance of a tubular heat exchanger with in-line perforated baffle with shutter type saw tooth turbulator. Heat Transfer, 53(5), 2234-2256.

DOI: 10.1002/htj.23034

[28] Sarah Rabeea Nashee, Zainalabden A. Ibrahim, Dhoha Kamil. Numerical Investigation of flow in vertical rectangular channals equipped with three different obstacles shape. AIP conference proceeding Fourth International Conference On Advances In Physical Sciences And Materials: Icapsm 2023, 17–18 August 2023,Coimbatore, India. Volume 3122, Issue 1. (2024).

DOI: 10.1063/5.0216016

[29] Hildebrand, Nathaniel, Pedro Paredes, and Meelan M. Choudhari. "Effect of a forward-facing step on the disturbance amplification in a flat-plate boundary layer." Physical Review Fluids 10.4 (2025): 043901.‏

DOI: 10.1103/physrevfluids.10.043901

[30] Nashee, Sarah Rabeea. Numerical simulation of heat transfer enhancement of a heat exchanger tube fitted with single and double-cut twisted tapes. Int J Heat Technol 42 (2024): 1003-10.‏

DOI: 10.18280/ijht.420327

[31] Hamzah, Mushtaq Talib, and Ali Lateef Tarish. Numerical Study of The Effect of Corrugated Wall on The Turbulent Forced Convective Heat Transfer and Fluid Flow Through a Forward-facing Step Channel. Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 67.1 (2020): 33-42.‏