Title :
Measurement of the skin friction associated with turbulent flows in air and water using SAW devices
Author :
Varadan, V.V. ; Roh, Y.R. ; Shankar, B. ; Varadan, V.K.
Author_Institution :
Pennsylvania State Univ., University Park, PA, USA
Abstract :
Shear stress measurement under dynamic loading by a low-frequency SAW (surface acoustic wave) sensor placed in a water channel with a fully developed turbulent flow and in an air flow generated by an electric fan is discussed. The SAW sensors used in the flow facility were fully calibrated for both shear stress and normal stress measurements, and hence, by measuring shifts in the oscillator frequency under flow conditions, actual values of the stress were obtained. The measured values show agreement with conventional intrusive measurement schemes. By using an appropriately sized SAW device and adjusting the frequency of operation, any spatial scale of the turbulence features can be characterized
Keywords :
detectors; flow measurement; shear turbulence; surface acoustic wave devices; ultrasonic applications; ultrasonic measurement; SAW sensor; air; dynamic loading; oscillator frequency; shear stress measurement; skin friction; turbulence sensors; turbulent flows; water; Acoustic measurements; Acoustic sensors; Acoustic waves; Fluid flow measurement; Frequency measurement; Friction; Oscillators; Skin; Stress measurement; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 1990. Proceedings., IEEE 1990
Conference_Location :
Honolulu, HI
DOI :
10.1109/ULTSYM.1990.171373
