Monday, October 31, 2011
External link: Article about Flying wings
If you are into flying wings like me, this PowerPoint slideset might interest you. It compares the basics of conventional airliner and flying wing airliner. Much bigger planes in other words, than my interest area. However, some of the pros and cons findings for each configuration also apply for the small version. Not all though as the starting point does not have engine nacelles and engines sticking out of the wing. http://www.engbrasil.eng.br/index_arquivos/ap23.pdf I haven't done yet comparison for the wetted area of a flying wing compared to a sailplane like structure. Logic tells that the flying wing in this size category might have more wetted area. But I am not sure. I need to design both and then measure the wetted area of both and compare. I am not a big fan of wing twist and the amount of wing twist on PUL-10 causes me shivers (wing tip twisted 10 degrees). That can't be good for cruise, simply can not. Ten degrees is insane amount of twist - on cruise the tips are on negative angle of attack and cause a lots of negative lift. The wing tips act as rather poor tails this way - it is very short coupled and if you have tail deflected that much on that close, the wing center section will need to lift also the negative lift of the tips which will make the plane to perform poorer. I am quite sure that a flying wing should be made stable without that much twist. I have a related idea for a flying wing: - one problem with flying wing is that flaps can not be used - what if you had small trim tails that look like the ones in SpaceShipOne. When flaps would be down, the trim tail, would cause opposing pitching moment to negate the pitching moment of the flap - The elevator control otherwise would be like on a flying wing, with elevons. - I haven't tried this out yet but it can be tested with RC model.