FLOW ANALYSIS ON SLOPED SURFACES  WITH DIFFERENT INCLINATION ANGLES

Nghiêm Hoàng Long; Phạm Văn Duy; Lê Đình Anh; Trần Thế Hùng

doi:10.34238/tnu-jst.7340

FLOW ANALYSIS ON SLOPED SURFACES WITH DIFFERENT INCLINATION ANGLES

About this article

Received: 15/02/23 Revised: 11/04/23 Published: 16/04/23

Authors

1. Nghiem Hoang Long, University of Engineering and Technology - Vietnam National University, Hanoi
2. Pham Van Duy, University of Engineering and Technology - Vietnam National University, Hanoi
3. Le Dinh Anh, University of Engineering and Technology - Vietnam National University, Hanoi
4. Tran The Hung , Le Quy Don Technical University

Abstract

This paper investigates the influence of inclination angle on flow field, surface pressure, separation and reattachment on the surface. The Reynolds-averaged Navier-Stokes equations (RANS) with turbulent model k-ɷ SST was applied for simulation. The numerical results with sloped angle of 25° were then compared with previous experimental data for validation. The influence of inclination angle was investigated with 10 specific cases, thereby determining aerodynamic characteristics such as pressure distribution, surface flow, separation and reattachment positions on the surfaces. The results indicated that the turbulent model shows a high ability in analyzing complex flow around the sloped surface. The numerical results showed that the separation flow occurs for sloped angles above 15°. Then the flow is reattached again on the horizontal surface to form a recirculation region. The length of recirculation regions increases with sloped angles and reaches a maximum value of around 7h for the sloped angle of 90°. The relation between surface flow and pressure distribution on the surface was discussed in detail.

Keywords

Wall shear stress; Inclination angles; Separation flow; Reattachment flow; Simulation

Full Text:

PDF (Tiếng Việt)

References

[1] G. Ceglia, M. Chiatto, C. S. Greco, F. D. Gregorio, G. Cardone, and L. de Luca, “Active control of separated flow over 2D back-facing ramp by an array of finite-span slotted synthetic jets,” Exp. Therm. Fluid Sci., vol. 129, 2021, Art. no. 110475.

[2] T. H. Tran, T. Ambo, T. Lee, L. Chen, T. Nonomura, and K. Asai, “Effect of boattail angles on the flow pattern on an axisymmetric afterbody surface at low speed,” Exp. Therm. Fluid Sci., vol. 99, pp. 324–335, 2018, doi: 10.1016/j.expthermflusci.2018.07.034.

[3] L. Chen, K. Asai, T. Nonomura, G. Xi, and T. Liu, “A review of Backward-Facing Step (BFS) flow mechanisms, heat transfer and control,” Therm. Sci. Eng. Prog., vol. 6, pp. 194–216, January 2018, doi: 10.1016/j.tsep.2018.04.004.

[4] H. Xiao, J. L. Wu, S. Laizet, and L. Duan, “Flows over periodic hills of parameterized geometries: A dataset for data-driven turbulence modeling from direct simulations,” Comput. Fluids, vol. 200, October 2020, doi: 10.1016/j.compfluid.2020.104431.

[5] Z. Zhou, T. Wu, and X. Yang, “Reynolds number effect on statistics of turbulent flows over periodic hills,” Phys. Fluids, vol. 33, no. 10, 2021, Art. no. 105124.

[6] R. Thibault and G. J. Poitras, “Uncertainty evaluation of friction velocity measurements by oil-film interferometry,” J. Fluids Eng. Trans. ASME, vol. 139, no. 5, 2017, doi: 10.1115/1.4035461.

[7] T. H. Tran, M. Anyoji, T. Nakashima, K. Shimizu, and A. D. Le, “Experimental Study of the Skin-Friction Topology Around the Ahmed Body in Cross-Wind Conditions,” J. Fluids Eng., vol. 144, no. 3, 2022, doi: 10.1115/1.4052418.

[8] T. H. Tran, M. Hijikuro, M. Anyoji, T. Uchida, T. Nakashima, and K. Shimizu, “Deflector effect on flow behavior and drag of an Ahmed body under crosswind conditions,” J. Wind Eng. Ind. Aerodyn., vol. 231, 2022, Art. no. 105238.

[9] O. Reynolds, “On the Dynamical Theory of Incompressible Viscous Fluids and the Determination of the Criterion,” in Proceedings of the Royal Society-Mathematical and Physical Sciences, 1995, vol. 451, no. 1941, pp. 5–47.

[10] F. R. Menter, “Two-equation eddy-viscosity turbulence models for engineering applications,” AIAA J., vol. 32, no. 8, pp. 1598–1605, 1994.

[11] T. H. Tran, D. A. Le, T. M. Nguyen, C. T. Dao, and V. Q. Duong, “Comparison of Numerical and Experimental Methods in Determining Boundary Layer of Axisymmetric Model,” in International Conference on Advanced Mechanical Engineering, Automation and Sustainable Development, 2022, pp. 297–302.

[12] D. C. Wilcox, Turbulence Modeling for CFD, 3rd Ed., Dcw Industries, Incorporated, 2006.

[13] W. M. Presz and E. T. Pitkin, “Flow separation over axisymmetric afterbody models,” J. Aircr., vol. 11, no. 11, pp. 677–682, 1974, doi: 10.2514/3.60403.

[14] T. H. Tran, “The Effect of Boattail Angles on the Near-Wake Structure of Axisymmetric Afterbody Models at Low-Speed Condition,” Int. J. Aerosp. Eng., vol. 2020, 2020, doi: 10.1155/2020/7580174.

[15] T. H. Tran and L. Chen, “Optical-Flow Algorithm for Near-Wake Analysis of Axisymmetric Blunt-Based Body at Low-Speed Conditions,” J. Fluids Eng., vol. 142, no. 11, pp. 1–10, 2020, doi: 10.1115/1.4048145.

[16] V. Gentile, F. F. J. Schrijer, B. W. van Oudheusden, and F. Scarano, “Afterbody effects on axisymmetric base flows,” 53rd AIAA Aerosp. Sci. Meet., January 2015, pp. 1–15, doi: 10.2514/6.2015-1535.

DOI: https://doi.org/10.34238/tnu-jst.7340

Refbacks

There are currently no refbacks.



Remember me