A skin friction sensor suitable for extreme conditions

• Experimental and numerical computation results for a new skin friction sensor.
• Sensor is non-invasive, particularly suitable for easily disturbed flows.
• Accuracy and performance comparable to known sublayer-fence sensors.
• Sensor calibration in a wind tunnel and numerical solutions.

This paper presents a simple sensor for measuring shear stress in fluid flow adjacent to a wall. Experiments and numerical flowfield computations have shown no measurable disturbance of the flowfield and the sensor may thus be well suited to conditions in which the invasive character of known sensors causes premature transition to turbulence or flow separation. The sensing part occupies a minimum surface area on the wall. In principle, the sensor is capable of detecting individual vortices in near-wall turbulence. Accuracy and sensitivity are comparable to known sensors of the sublayer-fence type.