On a post on the DreamFoil Creations Facebook page, Fred has shown a debug tool he has developed. According to him, “each line represent a blade tip vortice, the bright green areas are the ones which interacted with blades causing a slap”.
This is a companion discussion topic for the original entry at https://www.helisimmer.com/news/dreamfoil-creations-research-blade-splap-x-plane