A variable angle method of calibration for X-probes applied to wall-bounded turbulent shear flow

Abstract

A variable angle calibration technique for hot wire and hot film X-probes incorporating a new method of interpolation is described here along with measurements in a fully developed turbulent channel flow. Results based on the new method of calibration include the mean velocity profile, Reynolds stress, and probability density distributions for fluctuating velocity components u and υ and for the flow angle. Also skewness and flatness factors for u and υ are given. Measurement data were also evaluated using the conventional method. A comparison of both techniques shows that the new method does not yield appreciable differences in statistical flow analyses but is more accurate in measuring rare flow events associated with large flow angles. An extended version of the new method of calibration allowing three dimensional measurements in turbulent flow will be discussed.