Drag reduction in minichannel laminar flow past superhydrophobic surfaces

2021 ◽  
Vol 33 (12) ◽  
pp. 123608
Author(s):  
Henry Ems ◽  
Alfred Tsubaki ◽  
Ben Sukup ◽  
Siamak Nejati ◽  
Dennis Alexander ◽  
...  
Keyword(s):  
Laminar Flow ◽  
Drag Reduction ◽  
Superhydrophobic Surfaces ◽  
Flow Past

Numerical Simulation of Fluid Slip at a Hydrophobic Surface

Volume 4 ◽  
2004 ◽  
Author(s):  
Takao Fujita ◽  
Keizo Watanabe
Keyword(s):  
Boundary Condition ◽  
Laminar Flow ◽  
Circular Cylinder ◽  
Drag Reduction ◽  
Hydrophobic Surface ◽  
Friction Reduction ◽  
Water Repellent ◽  
Two Dimensional ◽  
Hydrophobic Property ◽  
Flow Past

Laminar drag reduction is achieved by using a hydrophobic surface. In this method, fluid slip is applied at the hydrophobic surface. An initial experiment to clarify for a laminar skin friction reduction was conducted using ducts with a highly water-repellent surface. The surface has a fractal-type structure with many fine grooves. Fluid slip at a hydrophobic surface has been analyzed by applying a new wet boundary condition. In this simulation, an internal flow is assumed to be a two-dimensional laminar flow in a rectangular duct and an external flow is assumed to be a two-dimensional laminar flow past a circular cylinder. The VOF technique has been used as the method for tracking gas-liquid interfaces, and the CSF model has been used as the method for modeling surface tension effects. The wet boundary condition for the hydrophobic property on the surface has been determined from the volume ratio in contact with water near the surface. The model with a stable gas-liquid interface and the experimental results of flow past a circular cylinder at Re = 250 without growing the Karman vortex street are made, and these results show that laminar drag reduction occurring due to fluid slip can be explained in this model.

Laminar Flow Past a Circular Cylinder: Reduction of Drag and Fluctuating Lift Using Upstream and Downstream Rods

2014 ◽  
Vol 493 ◽  
pp. 9-14
Author(s):  
Dedy Zulhidayat Noor ◽  
Eddy Widiyono ◽  
Suhariyanto ◽  
Lisa Rusdiyana ◽  
Joko Sarsetiyanto
Keyword(s):  
Reynolds Number ◽  
Laminar Flow ◽  
Circular Cylinder ◽  
Drag Reduction ◽  
Passive Control ◽  
Low Reynolds Number ◽  
Tandem Arrangement ◽  
Single Cylinder ◽  
Flow Past ◽  
Low Reynolds

Laminar flow past a circular cylinder has been studied numerically at low Reynolds number. The upstream and downstream rods have been used as passive control in order to reduce hydrodynamics forces acting on the cylinder. Both the upstream and downstream rods significantly contribute in reduction of drag and fluctuating lift compared to single cylinder without the rods. More detail, the upstream installation rod is more dominant in drag reduction than the downstream one. On the contrary, the downstream rod has suppressed the magnitude of the fluctuating lift almost twice that of the upstream configuration. Placing the two rods together as the upstream and downstream passive control in tandem arrangement has given more hydrodynamics forces reduction than the single rod configurations.Keywords:circular cylinder, passive control, tandem, drag, lift.

scholarly journals Simulations of laminar flow past a superhydrophobic sphere with drag reduction and separation delay

2013 ◽  
Vol 25 (4) ◽  
pp. 043601 ◽  
Author(s):  
Brian R. K. Gruncell ◽  
Neil D. Sandham ◽  
Glen McHale
Keyword(s):  
Laminar Flow ◽  
Drag Reduction ◽  
Flow Past

Mitigation of aerodynamic sound for a laminar flow past a square cylinder using a pair of cowl plates

2020 ◽  
Vol 32 (7) ◽  
pp. 076108 ◽  
Author(s):  
Bikash Mahato ◽  
Naveen Ganta ◽  
Yogesh G. Bhumkar
Keyword(s):  
Laminar Flow ◽  
Square Cylinder ◽  
Aerodynamic Sound ◽  
Flow Past

scholarly journals Sustainable Drag Reduction in Turbulent Taylor-Couette Flows by Depositing Sprayable Superhydrophobic Surfaces

2015 ◽  
Vol 114 (1) ◽  
Author(s):  
Siddarth Srinivasan ◽  
Justin A. Kleingartner ◽  
Jonathan B. Gilbert ◽  
Robert E. Cohen ◽  
Andrew J. B. Milne ◽  
...  
Keyword(s):  
Drag Reduction ◽  
Superhydrophobic Surfaces ◽  
Taylor Couette
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