Boundary Layer Combustion for Skin Friction Drag Reduction in Scramjet Combustors

2014 ◽  
Author(s):  
Ryan J. Clark ◽  
Shiva Om Bade Shrestha
Keyword(s):  
Boundary Layer ◽  
Drag Reduction ◽  
Skin Friction ◽  
Friction Drag ◽  
Scramjet Combustors ◽  
Friction Drag Reduction

Skin Friction Drag Reduction in Turbulent Boundary Layer Conditions over Riblet Surfaces

2019 ◽  
Author(s):  
Hidetoshi Iijima ◽  
Hidemi Takahashi ◽  
Seigo Koga ◽  
Monami Sasamori ◽  
Yoshimi Iijima ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Drag Reduction ◽  
Skin Friction ◽  
Friction Drag ◽  
Friction Drag Reduction

Freeman Scholar Review: Passive and Active Skin-Friction Drag Reduction in Turbulent Boundary Layers

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Marc Perlin ◽  
David R. Dowling ◽  
Steven L. Ceccio
Keyword(s):  
Boundary Layer ◽  
Drag Reduction ◽  
Skin Friction ◽  
Practical Implementation ◽  
Friction Drag ◽  
Polymer Injection ◽  
Morphological Alterations ◽  
Air Layers ◽  
Layer Flow ◽  
Friction Drag Reduction

A variety of skin-friction drag reduction (FDR) methods for turbulent boundary layer (TBL) flows are reviewed. Both passive and active methods of drag reduction are discussed, along with a review of the fundamental processes responsible for friction drag and FDR. Particular emphasis is given to methods that are applicable to external hydrodynamic flows where additives are diluted by boundary layer entrainment. The methods reviewed include those based on engineered surfaces (riblets, large eddy breakup devices (LEBUs), and superhydrophobic surfaces (SHS)), those based on additives (polymer injection and gas injection), and those based on morphological alterations in the boundary layer flow (air layers and partial cavity formation). A common theme for all methods is their disruption of one or more of the underlying physical processes responsible for the production of skin-friction drag in a TBL. Opportunities and challenges for practical implementation of FDR techniques are also discussed.

Experimental study of skin friction drag reduction of turbulent boundary layer over shallow dimples

2022 ◽  
Author(s):  
Md Abdur Razzak ◽  
Yong Dong Cui ◽  
Jonathan Tay ◽  
Zhen Wei Teo ◽  
Thirukumaran Nadesan ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Experimental Study ◽  
Turbulent Boundary Layer ◽  
Drag Reduction ◽  
Skin Friction ◽  
Friction Drag ◽  
Friction Drag Reduction

scholarly journals Research on Skin-Friction Drag Reduction by Hydrogen Injection in Supersonic Boundary Layer

2019 ◽  
Vol 37 (3) ◽  
pp. 449-456
Author(s):  
Shuai Wang ◽  
Guoqiang He ◽  
Fei Qin
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Drag Reduction ◽  
Skin Friction ◽  
Friction Reduction ◽  
Confined Space ◽  
Friction Drag ◽  
Wall Shear ◽  
Friction Drag Reduction

In order to investigate the applicability of the skin-friction reduction technique using hydrogen injecting into turbulent boundary layer, three-dimensional numerical simulation was carried out for a constant-cross-confined-space with rearward facing steps. The flow characteristics near wall surface and development of wall shear stress were analyzed and compared under different coming flow and injection conditions. The simulation results show that the hydrogen injection can achieve around 13.5% skin-friction drag reduction under the coming flow Mach number of 2.3Ma or 2.8Ma. At 2.8Ma, the optimal reduction profit is 13.5% which is obtained when the equivalent ratio is 0.06. The gases mixings are gradually enhanced along the flow path. At the positions of shock wave-boundary-layer interactions, the mixings are first strengthened and then suppressed, and meanwhile, the wall shear stress and density changes with similar law that first decreases and then rebounds at the positions. The declines of skin-friction drag decrease along the flow direction, the best reduction area can profit nearly 60%.

scholarly journals Base flow modulations for skin-friction drag reduction

2011 ◽  
Vol 318 (3) ◽  
pp. 032008 ◽  
Author(s):  
Jens H M Fransson ◽  
Alessandro Talamelli
Keyword(s):  
Drag Reduction ◽  
Skin Friction ◽  
Base Flow ◽  
Friction Drag ◽  
Friction Drag Reduction
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