Numerical Investigation of the Flow Structure on Ground Surface Mounted Square Prism

Abstract

The three-dimensional flow structure on a square prism mounted on a horizontal ground was investigated numerically using the Ansys Fluent program for Reynolds number Re = 250, 2500 and 〖2.5*10〗^6, using the Standard k-ε turbulence model equations. In the study, a square prism with a large Depth Ratio (DR = 4) was used. As a result, the information was obtained about the characteristic structure of the flow around the object. For z/h= 0.05, 0.5, 0.75 and 1, the top views of the Streamlines and Turbulent kinetic energy TKE data formed behind the ground surface-mounted square prism are shared. Streamlines and Turbulent kinetic energy TKE side views formed in the front, top and rear flow regions of the ground surface-mounted square prism for y/D=0, 0.25, 0.5, 0.75, 1 and 1.25 are presented. On the prism surfaces, the structure of the upstream and downstream flow changed due to separation from the prism front surface and reattachment of the flow. This situation revealed the effect of the Depth Ratio on the structure of the flow topology on the object by changing the drifting flow structure and turbulent kinetic energy structure in the wake region. As the Reynolds number acting on the prism increased, the size of the vortex decreased noticeably.

Keywords

• 3D Square Prism
• Separeted Flows
• Turbulence Simulation

References

1. Ansys Fluent Theory Guide 49-50 pp.
2. Chen, J., & Wu, J. (2024). Numerical investigation of vortex-induced vibration of a porous-coated cylinder at subcritical Reynolds number with a combined k-ε model for porous medium. Ocean Engineering, 304, 117828.
3. Durhasan, T. (2020). Flow topology downstream of the hollow square cylinder with slots. Ocean Engineering, 209, 107518.
4. Gao, Y., & Chow, W. K. (2005). Numerical studies on air flow around a cube. Journal of Wind Engineering and Industrial Aerodynamics, 93(2), 115-135.
5. Goswami, S., & Hemmati, A. (2023). Mean wake evolution behind low aspect-ratio wall-mounted finite prisms. International Journal of Heat and Fluid Flow, 104, 109237.
6. Kawai, H., Okuda, Y., & Ohashi, M. (2012). Near wake structure behind a 3D square prism with the aspect ratio of 2.7 in a shallow boundary layer flow. Journal Of Wind Engineering And Industrial Aerodynamics, 104, 196-202.
7. Korukçu, M. Ö. (2020). Kare silindir üzerinden laminer sürekli akışta blokaj oranının isı transferi ve akış karakteristiklerine etkisinin sayısal olarak incelenmesi. Uludağ Üniversitesi Mühendislik Fakültesi Dergisi, 25(1), 379-390.
8. Kucukkurt, O., & Karakus, C. (2024). Zemin yüzeye monteli küp üzerindeki akış yapısının sayısal olarak incelenmesi. AHI EVRAN International Congress on Scientific Research – IV, 578-590.

9. Liu R. (2019). Flow around with corner modification cross-sections, be power engineering of aircraft, [Master of thesis Nanjing University of Aeronautics and Astronautics, China].
10. Modesti, D. (2020). A priori tests of eddy viscosity models in square duct flow. Theoretical and Computational Fluid Dynamics, 34(5), 713-734.
11. Özmen, Y., & Kaydok, T. (2014). Kare kesitli bir yüksek bina üzerindeki türbülanslı akışın sayısal olarak incelenmesi. Kahramanmaras Sutcu Imam University Journal of Engineering Sciences, 17(2), 15-25. Peyvandi, E. (2024). Numerical study of condensation and conjugated heat transfer from flow in a heat exchanger. [Master of thesis Chalmers University of Technlogy].
12. Polat, C., Saydam, D. B., Söyler, M., & Özalp, C. (2022). Farklı en boy oranlarına sahip karesel prizmatik cisimler etrafındaki akış yapısının deneysel olarak incelenmesi. Düzce Üniversitesi Bilim ve Teknoloji Dergisi, 10(4), 1949-1959.
13. Rusdin, A. (2017). Computation of turbulent flow around a square block with standard and modified k-ε turbulence models. International Journal of Automotive and Mechanical Engineering, 14(1), 3938-3953.
14. Shaheed, R., Mohammadian, A., & Kheirkhah, Gildeh, H. (2019). A comparison of standard k–ε and realizable k–ε turbulence models in curved and confluent channels. Environmental Fluid Mechanics, 19, 543-568.
15. Tauqeer, M. A., Li, Z., & Ong, M. C. (2017). Numerical simulation of flow around different wall-mounted structures. Ships and Offshore Structures, 12(8), 1109-1116.
16. Yüce, B. E., & Pulat, E. (2017). Bir ofis odasındaki termal akışın kış şartlarında sayısal olarak incelenmesi. Teskon 2017 / Isıl Konfor Sempozyumu. 2017/080
17. Zargar, A. (2020). Characterization of the wake of large depth-ratio cylinders at low Reynolds numbers. [Department of Mechanical Engineering University Of Alberta Master of Science Thesis].
18. Zargar, A., Tarokh, A., & Hemmati, A. (2021). The steady wake of a wall-mounted rectangular prism with a large-depth-ratio at low Reynolds numbers. Energies, 14(12), 3579.
19. Zerrin, S. (2021). Kare silindir etrafında akış ve tümleşik taşınım ile ısı geçişi. Karaelmas Fen ve Mühendislik Dergisi, 11(2), 145-153.
20. Wang, F., & Lam, K. M. (2021). Experimental and numerical investigation of turbulent wake flow around wall-mounted square cylinder of aspect ratio 2. Experimental Thermal and Fluid Science, 123, 11032