A Miniature Flow Sensor Capable of Determining the Instantaneous High-Frequency Wall Shear Stress Fluctuations in Magnitude and Direction

The present paper deals with a wall shear stress sensor that is an improved modification of a conventional sublayer fence probe. Using a novel probe geometry - a so-called star probe - the measurement technique is capable of detemining the shear stress or the velocity close to the wall in magnitude and direction instantaneously at high temporal resolution. Hence, the novel probe enables significant gain in sensor capabilities compared to the conventional probe configuration. However, the directional resolution becomes more and more biased and damped with increasing frequency.