Emmons spot forcing for turbulent drag reduction

An Emmons spot-generation wind tunnel system has been designed to trigger closely spaced Emmons spots in the spanwise and longitudinal directions of an aerodynamic surface. For certain combinations of generator frequencies and amplitude, hole size, and hole spacing, experimental results indicate smaller turbulence scales and a reduction in skin friction of about 15 percent.

[1]  Dennis M. Bushnell,et al.  Turbulent drag reduction for external flows , 1983 .

[2]  J. W. Elder.  An experimental investigation of turbulent spots and breakdown to turbulence , 1960, Journal of Fluid Mechanics.

[3]  P. Bradshaw,et al.  Calculations of Viscous Transonic Flow over Airfoils , 1984 .

[4]  C. H. Priddin,et al.  The calculation of turbulent boundary layers on spinning and curved surfaces , 1977 .

[5]  R. D. Watson,et al.  Turbulent drag characteristic of small amplitude rigid surface waves , 1983 .

[6]  Israel J Wygnanski,et al.  Transitional boundary layer spot in a fully turbulent environment , 1977 .

[7]  W. Roger Briley,et al.  Numerical method for predicting three-dimensional steady viscous flow in ducts , 1974 .

[8]  D. M. Bushnell,et al.  Alteration of outer flow structures for turbulent drag reduction , 1983 .

[9]  P. S. Klebanoff,et al.  Characteristics of turbulence in a boundary layer with zero pressure gradient , 1955 .

[10]  Omer Savas,et al.  Coherence measurements in synthetic turbulent boundary layers , 1985, Journal of Fluid Mechanics.

[11]  Sanford Dash,et al.  Interactive phenomena in supersonic jet mixing problems. I Phenomenology and numerical modeling techniques , 1984 .

[12]  Yann Guezennec,et al.  A New View on Origin, Role and Manipulation of Large Scales in Turbulent Boundary Layers , 1982 .

[13]  P. Bradshaw,et al.  Calculation of Turbulent-Inviscid Flow Interactions with Large Normal Pressure Gradients , 1979 .

[14]  F. Chambers.  Synthetically Generated Turbulent Boundary-Layer Development and Structure , 1985 .

[15]  D. Spalding,et al.  A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows , 1972 .

[16]  Sanford Dash,et al.  Viscous/inviscid analysis of curved sub- or supersonic wall jets , 1985 .