Aerodynamics - KW MkII Rigid Flying Wing Foot Launch Hang Glider

[@gerryherman7420]

Thanks!

[@KlingbergWingMkII]

Glad you enjoyed the video and thanks for the generous donation! - Rol K.

[@SteveLewisFlyingWelshMan]

Wow, this is really great stuff. Thank you so much for putting up this remarkable educational resource. I think I may have to watch it several times for my 50 years (plus) old brain to take it all in. Your presentation is really packed full of information and delivered in a most expert and professional way. Thank you so much for sharing this material and your obvious depth of experience. I'm really enjoying following your project

[@KlingbergWingMkII]

Thank you very much, I'm glad folks are getting something positive from my efforts. I've spent more than 40 years working on flying wing designs and I'm thrilled to have KZbin which makes it easy to share my knowledge with so many people. Hopefully others will make good use of this information and build on the experiences I have gained.

[@SunilSundar]

Thank you for your time and generosity in sharing these videos. They are fascinating! I have a couple of questions; 1. Why the focus on yaw and yaw-roll coupled stability over pitch and roll stability? 2. What is an acceptable take-off speed for a foot launched aircraft? Btw: these questions came up the 2nd time I was watching this video. I'm sure I'll have even more questions when I watch it again!

[@KlingbergWingMkII]

Good questions! Pitch and roll stability are easy to achieve compared to the other factors. Flying wings are generally lightly damped in yaw. Often yaw and roll couple to cause dutch roll which can be annoying, but not dangerous. However, yaw stability problems can aggravate spanwise flow which can contribute to stall/spin. I'll ask a question to answer your second question - How fast can you run? Most folks can't do much more than 10 mph, but most gliders have stall speeds between 18 and 22 mph. So, how do they ever take off? Well, sometimes there is a headwind, sometimes there is a steep slope, and sometimes there is a cliff. All of them have different methods of getting up to flying speed - some more exciting than others. With flaps, my wing should have a takeoff speed around 22 mph. I don't plan on testing unless I have at least a 10 mph headwind! Thanks for the nice feedback.

[@SunilSundar]

@@KlingbergWingMkII Another question; The way I understand it, adverse yaw is the main problem with a rudderless aircraft. The way the Hortens and Al Bowers overcame this is by using the Prandtl or bell shaped lift distribution to obtain a proverse yaw Your solution is to use the auto yaw winglets So my question; How are you measuring the proverse yaw for a given roll at a given AoA? Or in other words, is there an ideal proverse yaw response for each flight condition or is that not a critical parameter?

[@LoveconQuersall73]

Mr klingburg I am a h3 and a huge fan of yours

[@KlingbergWingMkII]

Thanks for the support. Stay tuned, I'm sure it will be an amazing adventure - one way or the other!

[@Hutzpahh]

Thanks for a great informative video and for sharing your knowledge.

[@KlingbergWingMkII]

Great! It is my hope that all this info gets widely distribute to the aviation community and serves to make our activities safer while enjoying higher performance.

[@cliffcampbell8827]

What would happen if you added winglets on the end of each wing but they are semiflexible? They wouldn't be vertical but natural extentions to each wing. Another question I have is: what wo

[@KlingbergWingMkII]

I don't know. Maybe one of my viewers would like to tackle this one.

[@robertmason3812]

Hope this is Rol. Great work on the KW II. Still have a 2m wing and another kit. Also an X wing :). Still looking out for a sport wing. All great designs. Have studied your designs and Horten wings for many years.

[@KlingbergWingMkII]

Yep, it's me. It really gives me great joy to hear from some of my "old" customers/followers. I have to admit, out of all the work I've done in my life, some of the most rewarding was making the model kits. It is very satisfying when I hear that someone has had fun "playing" with something I created. I have a special reward for my long time followers. If you email me at [e-mail], I'll send you something special. Keep 'em flying!

[@lazarusmagellan2367]

i too am looking to build a flying wing and live near the california coast. Do you have any advice on using aluminum tubing vs electrical conduit for the frame? or other materials?

[@KlingbergWingMkII]

I will let my viewers answer this question. What do you folks have to say?

[@SunilSundar]

Thanks for the videos. Amazing stuff. What is the software you use called again? Sounded like Ice Flow...

[@KlingbergWingMkII]

Thanks for the kind words. Glad you enjoy the info. The aerodyanmic analysis software I use is called "Xflr5" It is freeware and available here: www.xflr5.com/xflr5.htm It is really written for model aircraft but if you have basic aero eng skills and use it on a comparative basis only, it can be very useful for full size aircraft design work.

[@SunilSundar]

@@KlingbergWingMkII Thanks Mr. Klingberg! I have a couple more questions that I hope you wouldn't mind answering; 1. What are the citeria for an aircraft to soar ? Is there a minimum L/D ratio or a lift to weight ratio or what? 2. How do you decide where to place control surfaces and how big they should be? Thanks again

[@KlingbergWingMkII]

Let's see, those questions are quite a bit harder than their shortness belies. 1. To soar means to stay aloft - to keep or gain altitude. Anything can soar if the lift is strong enough. I have seen parts of a barn soar in a tornado. If you want to know how well my current wing will soar, I can tell you that we are planning on trying to set the World's distance at 1000 km - that's a lot of soaring. 2. To do this type of calculation generally requires a degree in aero engineering and lots of hands on experience to fill in the gaps that theory does not address. That's why I use R/C models - helps me sort out difficult items like the ones in your question. So, most engineers start out with an educated guess, then test and revise as needed. Testing can be simulations and/or flight test.

[@alexmorillo3812]

good info...thanks for sharing

[@Hobi_gambar]

Nice

[@KlingbergWingMkII]

Thanks