Comparison test of the response to pitch angles of some digital hot wire anemometry techniques

The same real time hot-wire data have been processed digitally by the cosine law method and that of Friehe and Schwarz for various pitch angles of the probe holder. It was found that mean velocities and turbulence intensities can be measured quite accurately even at very high pitch angles by the cosine law, while shear stresses can be measured with much better accuracy by the Friehe and Schwarz method.