Drag Reduction in a Turbulent Channel Flow with Hydrophobic Wall

Nouri, Mahtab; Sekhavat, Setareh; Mofidi, Alireza

doi:10.1016/s1001-6058(11)60267-9

Cited by 30 publications

(14 citation statements)

References 16 publications

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“…The mean velocities from analytical solution of two dimensional Poiseuille flow and force model show a good agreement. In this situation, nearly 20% of drag reduction is observed in both numerical and analytical solutions, which are in suitable agreement with experiment results of Nouri et al (2012). They measured drag reduction of laminar flow in coated microchannel.…”

Section: Numerical Validation: Laminar Channel Flowsupporting

confidence: 86%

“…They assumed slip boundary condition in streamwise and spanwise direction and concluded that only the streamwise slip velocity led to the reduction in pressure drop. Nouri et al (2012) performed a variety of slip lengths with Navier's slip boundary condition in LES method and confirmed that a noticeable effect on the near wall turbulence structures occurred when the slip length was greater than a certain value.…”

Section: Introductionmentioning

confidence: 66%

“…Where 0 u is magnitude of the slip velocity at the wall and / w uy is the wall shear rate. Despite many researches indicating that slip length is linked to shear rate (Choi et al 2003), it is assumed independent in numerical simulations, which is acceptable for moderate shear rates (Min and Kim 2004;Nouri et al 2012). The most researchers used direct numerical simulation (DNS) or large eddy simulation (LES) to investigate the effects of hydrophobicity on drag reduction.…”

Section: Introductionmentioning

confidence: 99%

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Numerical Method to Predict Slip Length in Turbulent Channel Flow

Nouri

Rastan

Sekhavat

2016

JAFM

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In the present research work, we introduce a new method for estimating the slip length on superhydrophobic surfaces. Hence, a dynamic force is added to momentum equations and velocity boundary condition is rewritten in a new form. Laminar and turbulent channel flows are considered and two force functions are used with different profiles to investigate their effects on results. The turbulent channel flow is considered at Re 180   and the Large Eddy Simulation (LES) method has been applied to analyze this flow. All results indicate that this method can predict the streamwise slip length with a good accuracy, which is comparable with the Navier's method. So, using this numerical solution and also measuring pressure drop and mass flow rate in the channel, slip length can be calculated. Consequently, the errors and difficulties of slip length measurements in typical methods such as AFM and µPIV would be eliminated.

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Section: Numerical Validation: Laminar Channel Flowsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

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Numerical Method to Predict Slip Length in Turbulent Channel Flow

Nouri

Rastan

Sekhavat

2016

JAFM

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“…The present work revealed the changes of turbulent coherent structures by SH surface and some qualitative conclusions coincide with the results of DNS [13,14], there are still some limitations. Unlike DNS researches [13][14][15][16], the non-contact measurement work of slip velocity and slip length in macro-scale turbulent channel flow over SH surface is still a big challenge by TRPIV technique. The contact measurement method (e.g.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Effect of hierarchical structured superhydrophobic surfaces on coherent structures in turbulent channel flow

Tian

Zhang

Jiang

et al. 2015

Experimental Thermal and Fluid Science

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“…Hydrophobic surfaces are known to have a slip boundary condition on the wall which can support a shear-free air-water interface because of the properties of low surface energy and microstructures [4,5]. It is expected that this slip will lead to drag reduction in both laminar and turbulent regimes.…”

Section: Introductionmentioning

confidence: 99%