Yarana Rai ---- Yarana I hope some of the links below, together, offer the information you're looking for.

1)__ Aircraft Winglet Design Increasing the aerodynamic efficiency of a wing.

https://www.diva-portal.org/smash/get/diva2:1440647/FULLTEXT01.pdf

2)__ WINGLET DESIGN AND OPTIMIZATION FOR UAVS

https://shareok.org/bitstream/handle/11244/10086/Weierman_okstate_0664M_10946.pdf;jsessionid=1A06C9380CC6B66EB9041D26BA5F6A3A?sequence=1

3)__ Multidisciplinary Considerations in the Design of Wings and Wing Tip Devices

https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2643&context=facpub

4)__ Design Process: End Plates and Winglets

https://www.kitplanes.com/design-process-end-plates-and-winglets/

5)__ Design & Analysis of Winglets for Military Aircraft

(N.B. this is from Boeing Aircraft and published 1976)

https://apps.dtic.mil/sti/tr/pdf/ADA029345.pdf

6)__ Aerodynamic and Structural Design of a Winglet for Enhanced Performance of a Business Jet (2015 thesis)

(N.B. - Embry-Riddle Aeronautical University is the best aircraft engineering and design school in US)

https://commons.erau.edu/cgi/viewcontent.cgi?article=1264&context=edt

Here's what they consider:

• Strength & Weight: Strong enough to handle extra forces, but lightweight to avoid negating fuel benefits.
• Aeroelasticity: Avoid unwanted vibrations or instability caused by the winglet.
• Ground Clearance: Ensure the winglet doesn't scrape the ground during takeoff or landing.
• Manufacturing: Keep it simple and cost-effective to build and maintain.
• Drag: Minimize extra drag caused by the winglet's shape and exposed surface area.
• Ice Accumulation: Design to minimize ice buildup, especially for aircraft in icy conditions.
• Compatibility: Make sure the winglet integrates well with the existing wing structure.
• Cost-Effectiveness: Balance the fuel savings with the cost of design, manufacturing, and maintenance.