SLIPPYBLUEKNOBE 0 #1 January 31, 2008 I have been a bite confused apparently about which is more efficient? It was always my belief that the closed nose had more to do with creating a smooth surface for the air to move around the wing, (Velo, and the GLX) now it seams that its more just for slowing the Openings down. With the release of the spire? I have also just seen a newer GLX with a completely open nose. Any one else? Quote Share this post Link to post Share on other sites
diablopilot 2 #2 January 31, 2008 You're right, a closed nose IS more efficient, as it forms a cleaner leading edge, and improves laminar flow over and around the wing. GL canopies need to be able to inflate, and re-inflate fast, so open nose is preferable. I haven't seen much of the Spire, but the GLX was being constructed with 3 center cells open and outboard cells restricted as a compromise, using cross-ports to aid in the inflation/pressurization of the outboard cells. The slower openings with he closed nose are a by-product.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
SLIPPYBLUEKNOBE 0 #3 February 1, 2008 Hay thanks for the reply. Here is a Quote from Jim S. on Canopypiloting.com "Re: [sidarapr] New Daedalus GLS XF! (pictures) [In reply to] Can't Post Closed leading edges, like the wing of a aircraft are the best, if they are made of rigid composites that do not bend or change shape. Because of this the closed nose configuration (Which Jyro from NZ created for the X braced design) is best for the openings. However, if we didn't need to go through the whole opening sequence then you would see Jimmy here flying a JVX all sail with the nose completly open! A more open nose has more air ramming into the canopy...at all times. More air ramming into the canopy means more pressure...at all times The more pressure you have the more rigid the parachute which is quicker to inflate...specially when you need it to. The hybrid nose gives you the best of both worlds....Open more in the center three cells and closed off on the outside three cells. The choice is yours... " I was having some trouble signing on there or I'd of just asked him, but I still kinda wanted to through it out there anyway. I was aware of the center cells being open on the glx. I thought that it was a selling point of the canopy witch is what brought up my question in the first place. Why does the glx now have a completely open nose? Or maybe its just an option? Quote Share this post Link to post Share on other sites
yuri_base 1 #4 February 1, 2008 QuoteIt was always my belief that the closed nose had more to do with creating a smooth surface for the air to move around the wing For air, hitting the vertical membranes of the [almost] closed cells head-on is about as bad as hitting the stagnant air in front of the open cells. I think that small inlets are to make the wing more rigid. High dynamic pressure created by high speed provides plenty supply of air, so inflation is not a problem. Imagine a thin inflatable mattress (like ThermaRest). When you inflate and seal it, it's quite rigid. If you make many big holes in it and maintain the same pressure dynamically by a pump, with air running out of the holes, the mattress won't be as rigid as before. More rigid wing means it can be flatter spanwise. The lift vectors from all areas of the canopy are now pointing more vertically, resulting in higher lift.Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio Quote Share this post Link to post Share on other sites
jakee 1,257 #5 February 1, 2008 QuoteYou're right, a closed nose IS more efficient, as it forms a cleaner leading edge, and improves laminar flow over and around the wing. You either have laminar flow or you don't. I very much doubt that any inflatable fabric canopy has it.Do you want to have an ideagasm? Quote Share this post Link to post Share on other sites
UDSkyJunkie 0 #6 February 2, 2008 Quote You either have laminar flow or you don't. I very much doubt that any inflatable fabric canopy has it. hehe... damn engineers pointing out reality again... I have to agree that there isn't a fabric wing on earth with laminar flow to speak of. Hell, it took until the P-51 to figure out how to make a full-laminar airfoil out of metal. That said, I think his point is accurate, but would be better worded "... as it forms a cleaner leading edge, and reduces turbulence over and around the wing.""Some people follow their dreams, others hunt them down and beat them mercilessly into submission." Quote Share this post Link to post Share on other sites
hparrish 0 #7 February 3, 2008 Uhhghh okay I think you have all proven how much people like me don't know about the engineering aspect of canopies.Perhaps the Moderators can create a Geeky, Nerdy, Engineering Discusions Forum for you propeller heads. Quote Share this post Link to post Share on other sites
