Experiment Evaluation of Skin Friction Drag by Surface Tailoring

International Conference on Materials, Alloys and Experimental Mechanics 2017

材料科学;金属学;机械制造

Manigandan, S.^1 ; Krishna, K. Gopal^1 ; Kumar, K Gagan^1 ; Gunasekar, P.^1 ; Nithya, S.^1

Department of Aeronautical, Sathyabama University, Chennai

600119, India^1

关键词: Atmospheric conditions;    Boundary layer thickness;    Energy expenditure;    Numerical results;    Polished surfaces;    Skin-friction drag;    Transverse shear stress;    Wind-tunnel testing;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/225/1/012062/pdf
DOI  :  10.1088/1757-899X/225/1/012062

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Reduction of drag is an important role of aerodynamic specialist in real time world. The performance of forward moving object improved when the drag is reduced. Skin friction drag caused when the fluid tending to shear along the surface of the body and it is dependent on energy expenditure. Initial research concluded that nearly 20 to 40% of total drag is skin friction drag, based on flight forward velocity. This means a lot of fuel burned. In this paper we investigate a methodology to reduce the skin friction drag by implementing different kinds of exterior treatments. The ideology inspired from the world fastest moving oceanic creature. Structures are fabricated based on the replica of scales of the oceanic creature. The outer skin of the aerofoil NACA0012 is modified like shark scales. Then it is tested using open type sub sonic wind tunnel. In addition to that, the leading edge thickness effect also studied. The turbulent flow phenomenon is validated at different velocities and compared with numerical results using STAR CCM+. From the plots and graphical results, it is found that the skin friction drag is generated less due to reduction of transverse shear stress present in turbulent flow and skin friction drag depends on boundary layer thickness and on the percentage of chord of flow separation. In addition to this, the result delivers that the ordinary polished surface produces more drag than the modified scales. The outlook of this technology is excrescence for different applications. This open section wind tunnel testing produces 10-15% reduction in drag and can be turn to high values when the experiment is conducted in closed section wind tunnel with real time atmospheric conditions, which can be done as a future work.