This is the third video in a series summarizing my notes for the design, analysis, fabrication, and testing of flying wing style aircraft from an engineer's approach. This video builds upon Part 1 and Part 2, so please go watch those videos and understand their content before watching this one. This video covers induced drag and tackles some common misconceptions, reviews efficiency and how lift-induced downwash effects can change both lift and drag along a wing, and the aerodyanmic pricniples behind winglets. Towards the end, there's a nice summary that wraps up the video, reviewing what questions to ask when thinking about implementing a winglet and, if a winglet is selected to implement in your design for one of those reasons, how to get in the ballpark of a 'good' design before getting tangled in the weeds of detailed design.
Again, if you catch something that is incorrect here, please let me know! I filtered through the final cut as best as I could, but I'm here to learn, so I'm all ears!
0:00 Intro
0:32 Drag Breakdown
1:59 Induced Drag
7:15 Reducing Induced Drag
9:05 Winglet Aerodynamics
17:08 Span Extension Limitations
18:03 Effects at the Wingtip Region
21:51 Winglet Design
25:50 Upturned or Downturned Winglet?
27:53 Winglet Extension vs Winglet
29:18 Summary of Winglet Aerodynamics/Design