A modified-Liutex-based vortex-core-line extractor and its application

Vortices, which appear as swirling behaviour of a flow field, are an important phenomenon in fluid dynamics, and the extraction of vortex cores is necessary for the research of vortex evolution in many areas of fluid mechanics. The Liutex method is a milestone in vortex identification and provides a reasonable mathematical definition for a vortex core. Based on this definition, a novel integration-based method is presented, which can reduce the numerical error in the integration process through location optimization. Two typical test cases, the wake vortices of an A320 in the near-ground stage and a helicopter rotor, are examined to show that the proposed method can extract continuous vortex core lines with accuracy and efficiency for vortex parameter study.