Skin friction measurements on reflective surfaces using nematic liquid crystal

2000 ◽  
Vol 28 (1) ◽  
pp. 64-73 ◽  
Author(s):  
D. R. Buttsworth ◽  
S. J. Elston ◽  
T. V. Jones
Keyword(s):  
Liquid Crystal ◽  
Skin Friction ◽  
Nematic Liquid Crystal ◽  
Friction Measurements ◽  
Reflective Surfaces

Direct Full Surface Skin Friction Measurement Using Nematic Liquid Crystal Techniques

1998 ◽  
Vol 120 (4) ◽  
pp. 847-853 ◽  
Author(s):  
D. R. Buttsworth ◽  
S. J. Elston ◽  
T. V. Jones
Keyword(s):  
Mathematical Model ◽  
Liquid Crystal ◽  
Skin Friction ◽  
Nematic Liquid Crystal ◽  
Measurement Techniques ◽  
Surface Measurement ◽  
Calibration Data ◽  
Surface Shear Stress ◽  
Orientation Technique ◽  
Friction Measurements

New techniques for the direct measurement of skin friction using nematic liquid crystal layers are demonstrated. Skin friction measurements can be made using a molecular rotation time technique or an equilibrium orientation technique. A mathematical model describing the molecular dynamics of the nematic liquid crystal layer has been introduced. Theoretical results from the proposed mathematical model are in excellent agreement with the current experimental measurements. It is thus demonstrated that the present model captures the essential physics of the nematic liquid crystal measurement techniques. Estimates based on the variance of the liquid crystal calibration data indicate that skin friction measurements to within ±4 percent should certainly be possible. The techniques offer the considerable advantage of simplicity, without any compromise on the accuracy, relative to other surface shear stress measurement techniques. The full surface measurement capacity of the equilibrium orientation technique is demonstrated by measuring the skin friction distribution around a cylindrical obstruction in a fully developed laminar flow.

Direct Full Surface Skin Friction Measurement Using Nematic Liquid Crystal Techniques

1997 ◽  
Author(s):  
D. R. Buttsworth ◽  
S. J. Elston ◽  
T. V. Jones
Keyword(s):  
Mathematical Model ◽  
Liquid Crystal ◽  
Skin Friction ◽  
Nematic Liquid Crystal ◽  
Measurement Techniques ◽  
Surface Measurement ◽  
Calibration Data ◽  
Surface Shear Stress ◽  
Orientation Technique ◽  
Friction Measurements

New techniques for the direct measurement of skin friction using nematic liquid crystal layers are demonstrated. Skin friction measurements can be made using a molecular rotation time technique or an equilibrium orientation technique. A mathematical model describing the molecular dynamics of the nematic liquid crystal layer has been introduced. Theoretical results from the proposed mathematical model are in excellent agreement with the current experimental measurements. It is thus demonstrated that the present model captures the essential physics of the nematic liquid crystal measurement techniques. Estimates based on the variance of the liquid crystal calibration data indicate that skin friction measurements to within ± 4 % should certainly be possible. The techniques offer the considerable advantage of simplicity, without any compromise on the accuracy, relative to other surface shear stress measurement techniques. The full surface measurement capacity of the equilibrium orientation technique is demonstrated by measuring the skin friction distribution around a cylindrical obstruction in a fully developed laminar flow.

Ising-Bloch transition in a nematic liquid crystal

1994 ◽  
Vol 4 (2) ◽  
pp. 319-331 ◽  
Author(s):  
J.M Gilli ◽  
M. Morabito ◽  
T. Frisch
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal

LIQUID CRYSTLASLIGHT SCATTERING BY FLUCTUATIONS INDUCED BY AN APPLIED ELECTRIC FIELD IN A NEMATIC LIQUID CRYSTAL (APAPA)

1972 ◽  
Vol 33 (C1) ◽  
pp. C1-63-C1-67 ◽  
Author(s):  
M. BERTOLOTTI ◽  
B. DAINO ◽  
P. Di PORTO ◽  
F. SCUDIERI ◽  
D. SETTE
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Nematic Liquid Crystal ◽  
Applied Electric Field
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