On Turbulence Measurements with a Split-Film Probe

One of the main shortcomings of hot-wire technique for use in turbulent boundary layers is the difficulty in measuring the turbulent shear stress \(- \rho \overline {{\text{u'v'}}}\) near the solid wall (y < 1 mm) due to the size of the x-wire probes. To overcome this disadvantage the split-film probe was developed by TSI. This device is a miniature sensor consisting of a quartz cylinder coated with two thin platinum films, separated by two gaps along the axis of the cylinder.