|Table of Contents|

Mechanism of Drag Reduction Due to Spanwise Wall Oscillation in Turbulent Channel Flow

《南京理工大学学报》(自然科学版)[ISSN:1005-9830/CN:32-1397/N]

Issue:
2010年03期
Page:
361-366
Research Field:
Publishing date:

Info

Title:
Mechanism of Drag Reduction Due to Spanwise Wall Oscillation in Turbulent Channel Flow
Author(s):
HUANG Le-pingFAN Bao-chunDONG Gang
National Key Laboratory of Transient Physics,NUST,Nanjing 210094,China
Keywords:
channel flow near-wall turbulence spanwise wall oscillation drag reduction spectral method direct numerical simulation
PACS:
O357.5
DOI:
-
Abstract:
In order to suppress near-wall turbulence and reduce skin-friction drag,the mechanisms of turbulence suppression and drag reduction due to spanwise wall oscillation in turbulent channel flow are investigated by direct numerical simulation(DNS) based on standard Fourier-Chebyshev spectral method.The database of turbulent channel flow is produced by DNS.The friction drag can be reduced significantly by changing the amplitude and the period of the spanwise wall oscillation.With the increase of the mean drag reduction rate,time evolution of skin-friction drag becomes steadier and shows longer periodicity.A typical drag reduction periodicity is divided to three phases for analyzing the mechanism of drag reduction.The results show: the structures of near-wall turbulence take on different states in the three typical phases;two kinds of mechanisms of turbulence suppression and drag reduction due to spanwise wall oscillation work by turns,one of which is the incline of streamwise vorticity and streaks,leading to creation of a negative spanwise vorticity,and the other of which is the relative displacement of the streamwise vorticity and streaks,making the streaks broad and the streamwise vorticity weak.

References:

[1] Cho iK S, G raham M. Drag reduction of turbulent p ipe flow s by c ircular-w a ll osc illa tion [ J] . Phy s F lu ids, 1998, 10( 1): 7- 9.
[2] Tru jillo SM, Bogard D, Ba ll K. Turbulent boundary layer drag reduction us ing an osc illating w all[ R ]. AIAA 1997- 1870.
[3] Bogard D C, BallK S, W assen E. Drag reduction fo r turbulent layer flow s using an oscillating w a ll [ R ]. AFOSR TTCRL 00-2.
[4] 黄伟希, 许春晓, 崔桂香, 等. 壁面展向周期振动的 槽道湍流减阻机理的研究[ J] . 力学学报, 2004, 36 ( 1): 24- 30.
[5] Zhao H, Wu J Z, Luo J S. Turbulent drag reduction by trave ling w ave of flex ib le w all[ J]. Fluid Dynam ics Research, 2004, 34( 3): 175- 198.
[6] 黄乐萍, 董刚, 范宝春, 等. 展向周期振动的平板近 壁湍流结构研究[ J]. 水动力学研究与进展( A 辑), 2008, 23( 3): 294- 300.
[7] 黄乐萍, 董刚, 范宝春. 槽道流壁面展向周期振动 减阻的一维谱分析[ J]. 宇航学报, 2009, 30( 5): 1777- 1784.
[8] Cho i K S. Near-wa ll struc ture of turbu lent boundary layer w ith spanw ise-wa ll o sc illation[ J]. Phys F lu ids, 2002, 14( 7): 2530- 2542.
[9] Zhou J, Adr ian R J, Ba lachandar S, et a .l M echanism s fo r g enerating cohe rent packets o f hairpin vo rt-i ces in channe l flow [ J] . J Flu id M ech, 1999, 387 ( 1): 353- 396.
[10] Cho i K S, C layton B R. The m echan ism of turbulent drag reduction w ith wa ll osc illation [ J] . H eat F lu id F low, 2001, 22( 1) : 1- 9.
[11] SchoppaW, H ussa in F. Coheren t structure genera tion in nea r-w all turbu lence[ J]. J F lu idM ech, 2002, 453 ( 1): 57- 108. 366

Memo

Memo:
-
Last Update: 2010-06-30