L. Lofdahl et al., SMALL SILICON-BASED PRESSURE TRANSDUCERS FOR MEASUREMENTS IN TURBULENT BOUNDARY-LAYERS, Experiments in fluids, 17(1-2), 1994, pp. 24-31
Small silicon based sensors for the measurement of wall-pressure in tu
rbulent flows have been designed and fabricated using microelectronic
technology. The sensor diaphragms have a side length of 100 and 300 mu
m, and polysilicon piezoresistive gauges were used for detection of th
e deflection. A two-dimensional flat plate boundary layer was employed
to determine the performance of the pressure transducers, and compari
sons with established data from the literature were made. A threshold
value for the pressure fluctuations of about the double Kolmogorov len
gth scale was estimated independently from the probability distributio
n as well as from the power spectra. In good agreement with theoretica
l predictions of Blake (1986), the slope of the power spectra was foun
d to be omega-1 in the intermediate and omega-5 in the high frequency
range.