An instrument for wall shear stress measurement

The instrument is designed for wall shear stress measurement, operating with flexible hot film sensors or floating-element sensors. The hot film sensor can be used to measure the wall shear stress on curved surfaces. And the floating-element sensor directly senses wall shear stress, and the output signal has good linear characteristics. The application software of the instrument is developed to analyze wall shear stress and flow phenomena of the boundary layer. The benchmark experiments of the flat plate were conducted in wind tunnels to show that the instrument with hot film sensors has a related normalized standard deviation of 1.02%, and with floating-element sensors has a related normalized standard deviation of 0.92% and a good linearity of 1.5%. And dynamic calibrations of the instrument with floating-element sensor show that the instrument has a dynamic response up to 6500 Hz.