Wall shear sensors with multiple independent flexures and measurement systems including the wall shear sensors

A wall shear measurement system comprising:

• a test body having a flow surface;
• at least one sensor housing mounted to the test body;
• and
• a wall shear sensor in the at least one sensor housing, the wall shear sensor comprising:
• a floating element fixedly attached to a base, the floating element having a sensing head opposite the base, a first flexure between the sensing head and the base and being along a longitudinal axis of the floating element defined perpendicular to the base, and a second flexure between the first flexure and the base and being along the longitudinal axis;
• and
• at least one strain gauge coupled to the first flexure to measure a first directional component of wall shear applied across a floating element surface of the sensing head;
• at least one strain gauge coupled to the second flexure to measure a second directional component of wall shear applied across the floating element surface of the sensing head,
• wherein:
• the first flexure is oriented along a first transverse axis of the floating element, the first transverse axis being perpendicular to the longitudinal axis;
• the second flexure is oriented along a second transverse axis of the floating element, the second transverse axis being perpendicular to the longitudinal axis;
• the first transverse axis and the second transverse axis define an offset angle;
• the offset angle is from greater than 0° to less than 180°;
• the sensor housing laterally surrounds the floating element;
• an interior space laterally surrounding the floating element is defined between the floating element and the sensor housing;
• the interior space comprises a small gap portion laterally surrounding the sensing head of the floating element;
• the head surface of the sensing head is exposed outside the sensor housing.