Wall shear sensors with multiple bending beam flexure 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, and a split-beam flexure between the sensing head and the base, a longitudinal axis of the floating element being defined perpendicular to the base;
• and
• at least one strain gauge coupled to the split-beam flexure that measures a strain imposed on the split-beam flexure when a wall shear is applied across a head surface of the sensing head,
• wherein:
• the split-beam flexure comprises a single cantilever beam split into a first beam and a second beam by at least one channel defined through the split-beam flexure parallel to a first transverse axis of the floating element, the first transverse axis being perpendicular to the longitudinal axis;
• the wall shear sensor sways in a sway direction parallel to a second transverse axis that is perpendicular to both the transverse axis and the longitudinal axis of the floating element when the wall shear is applied;
• the wall shear sensor mechanically isolates measurement of the wall shear by the at least one strain gauge from moments induced on the sensing head by impinging pressure gradients or shock waves;
• the sensor housing laterally surrounds the floating element of the wall shear sensor;
• 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;
• and
• the head surface of the sensing head is exposed outside the sensor housing.