On the vortex identification within a linear blade cascade - an experimental research

Abstract

This paper deals with the identification of the individual vortical structures within a linear blade cascade based on H criteria. The experimental data obtained from the pressure measurement at the cascade outlet were evaluated by a standard procedure to obtain the velocity field in one plane. Then, the vorticity in the flow field was evaluated based on Crocco’s theorem, and in the final step, the helicity density was calculated. The impact of the inlet flow angle on the velocity field as well as on the vortical structures was investigated. The effect of the value of the H threshold on the vortex identification is discussed in the last part of the paper.