Skin friction measurements on reflective surfaces using nematic liquid crystal

Citation
Dr. Buttsworth et al., Skin friction measurements on reflective surfaces using nematic liquid crystal, EXP FLUID, 28(1), 2000, pp. 64-73
Citations number
21
Categorie Soggetti
Mechanical Engineering
Journal title
EXPERIMENTS IN FLUIDS
ISSN journal
07234864 → ACNP
Volume
28
Issue
1
Year of publication
2000
Pages
64 - 73
Database
ISI
SICI code
0723-4864(200001)28:1<64:SFMORS>2.0.ZU;2-Z
Abstract
A new liquid crystal technique for full surface skin friction measurements is introduced. With the new technique, the transmission of light through ne matic liquid crystal viewed in reflection provides a quantitative measureme nt of the skin friction. The measurement technique is discussed with the ai d of a model which describes the rotation dynamics of the liquid crystal mo lecules. Calibration experiments performed in a laminar flow duct demonstra te that the model captures the essential physics of the new technique. The measurement of skin friction downstream of a three dimensional roughness el ement in an incompressible laminar boundary layer is then presented as a de monstration of the utility of the technique.