Effect of a Small Surface Wave on Boundary-Layer Transition

摘要

Surface imperfections affect boundary-layer stability directly. A series of flight tests have been completed by the Aerion Corporation on a Cessna CitationJet airplane to evaluate the extent of natural laminar flow (NLF) on an operational aircraft. The sealant used to fill a junction between the leading edge and the wing box creates a step which over time deteriorates and forms a wavelike surface imperfection. Test flights were completed to determine the extent of NLF based on sealant condition at the leading edge joint. The waviness of the joint has been characterized and its effect on natural transition was analyzed numerically to better understand the transition process.