Unsteady boundary layer transition detection by automated analysis of hot film data

Abstract

Several analysis algorithms were investigated for the detection of transition on the pitching airfoil DSA-9A. The state of the art method to detect unsteady boundary layer transition with experimental hot film data is a manual approach. Therefore, to reduce the investigation time and improve the data quality an automated detection has been created. In the most cases the computation time of the unsteady boundary layer detection is almost two orders of magnitude faster compared to manual extraction. Several algorithms will be discussed in this paper of which an algorithm utilizing the skewness produces the best results in a robust implementation.