An Integrated Silicon Based Pressure-Shear Stress Sensor for Turbulence Measurements

Paper i proceeding, 1996

An integrated silicon pressure-shear stress sensor has been designed, fabricated and tested in a turbulent wall-boundary layer. The piezoresisitve pressure sensor is based on a polysilicon diaphragm technology and the thermal shear stress sensor on the gas cooling of a polyimide insulated heated chip. The pressure sensor diaphragm area is 100 x 100 μm, the top area of the shear stress sensor hot chip is 300 x 60 μm and the edge-to-edge distance between the two areas is 100 μm. The measured steady-state power dissipation of the shear stress sensor in a turbulent wall-boundary layer at an over-temperature of 100 degrees Celsius was ___ where ___ is the time-average wall shear stress. The new integrated sensor has been applied for the simultaneous measurement of fluctuating pressure and shear stress in a flat plate boundary layer at a Reynolds number range of ___. Pressure-shear stress correlations coefficients were found between 0.40 and 0.50 for the parallel, and between 0.20 and 0.25 for the perpendicular configuration to the mean flow.