ManBird 0 #1 July 8, 2003 What would the repurcussions be, if any, to removing the mesh from the inlets on a wingsuit? I'm considering doing this to my GTi to improve inflation time. Would I also lose air quickly? One negative might be the possibility of dirtying up the suit on the inside, but I could live with that. I may even stitch in some airlocks, provided I can acquire the proper materials. This experiment would, as I see it, either leave the wings more rigid throughout the flight and perform better, or it might just turn it into a "floatier" suit. I'm not entirely sure how significant the difference would be, either, but when you really look at it, the mesh covers a lot of real estate on the inlets. Is there some really big aerodynamic feature I'd be killing if I made this alteration? It feels like I'm missing something big. Edited to add: I could also be cool like Kevin and get glowsticks in my wings for night jumps (which are coming up this Friday)."¯"`-._.-¯) ManBird (¯-._.-´"¯" Click Quote Share this post Link to post Share on other sites
andy2 0 #2 July 9, 2003 you may already have done so, but if not ask BM!! Report back what they say, sounds like a neat idea. --------------------------------------------- let my inspiration flow, in token rhyme suggesting rhythm... Quote Share this post Link to post Share on other sites
SkymonkeyONE 4 #3 July 9, 2003 Actually, I think that removing the webbing would allow that air inlet to distory in flight. Imagine removing the rib from the cell of a parachute. The cell would open into a circle. If you removed the mesh, I think you would have to reinforce the hole with some smaller grid of fabric to maintain the shape of the inlet. Quote Share this post Link to post Share on other sites
blair700 0 #4 July 9, 2003 QuoteEdited to add: I could also be cool like Kevin and get glowsticks in my wings for night jumps (which are coming up this Friday). Just be sure to take them out before you stuff them in your gearbag for the night Otherwise you may end up with a tie-dye GTI Blair Quote Share this post Link to post Share on other sites
ManBird 0 #5 July 9, 2003 QuoteActually, I think that removing the webbing would allow that air inlet to distory in flight. Imagine removing the rib from the cell of a parachute. The cell would open into a circle. If you removed the mesh, I think you would have to reinforce the hole with some smaller grid of fabric to maintain the shape of the inlet. Exactly my thoughts. I've heard a number of people ask why wingsuits inlets on every cell, like a parachute. It's because wingsuits don't have suspension lines, and the inlets would distort. Maybe just thin, strong materials to form a few "gills" or "bars"... just enough to hold its shape, while letting as much air in as possible."¯"`-._.-¯) ManBird (¯-._.-´"¯" Click Quote Share this post Link to post Share on other sites
SkymonkeyONE 4 #6 July 9, 2003 The problem here is that I don't think you need any more inflation in your wings. Crossbraced parachutes of today have incredibly small air inlets and remain very pressurized. What we strive for is minimal drag while allowing just enough air in to maintain optimum pressurization. Chuck Quote Share this post Link to post Share on other sites
ManBird 0 #7 July 9, 2003 True. That's why I think one possibility is that it would turn it into a "floatier" suit. But on the other hand, I look at the ProTrack charts, and the inflation of the wings (namely at the ends) and see the amount of time it takes to decrease the fall rate from say, 60 MPH to 50 MPH, and it seems a little long. That's why I'm thinking airlocks. After a good swoop, your wings lose pressure, deflate, and your fall rate increases dramatically, then you have to fly for a good six - ten seconds to get your fall rate back. But what if you swooped, got a nice low fall rate at the end, and then didn't lose pressurization? Your burn off of forward speed would drop you a bit, but recovery would be much faster with your wings already inflated/pressurized. Ever seen an airlocked canopy get cutaway? It still flies without suspended weight, because it maintains pressurization. I've watched my wings, even on my S3, deflate after a swoop. On the S3, the inlet is larger (plus there's the inlets in the sleeve), and repressurization happens significantly faster than on my GTi. Still just in theory stage. I e-mailed Robert. If anyone's the authority, it's him. Edited for spelling."¯"`-._.-¯) ManBird (¯-._.-´"¯" Click Quote Share this post Link to post Share on other sites
TB99 0 #8 July 9, 2003 Those things on your sleeves are deflectors, not inlets ... they make the airflow over your wing smoother instead of a twirly tornado. Smoother slipstream; they don't do anything for "pressurization." I think it would be a bad idea to do what you are suggesting. Trailer 11/12 was the best. Thanks for the memories ... you guys rocked! Quote Share this post Link to post Share on other sites
ManBird 0 #9 July 9, 2003 QuoteThose things on your sleeves are deflectors, not inlets ... they make the airflow over your wing smoother instead of a twirly tornado. Smoother slipstream; they don't do anything for "pressurization." I think it would be a bad idea to do what you are suggesting.In the sleeves, not on the sleeves. I was referring to the inlets at the top of the ribs inside the sleeve, not the deflectors on top (in regards to the S3). And I'm only referring to the inlet at the armpit that cross the first cell (and part of the second) on the front/bottom (depending on how you're looking at it) of the wing on the GTi. I wouldn't make this mod to my S3, anyway. The S3... my precious... we won't hurts it... er... Edited to add: The deflectors on the arm wings are not turbulence preventers, as there is nothing in the way to cause turbulence there (though they would smooth the air out if something was there). They route air from below and infront of the wing to the top of the wing, thus putting pressure on it, thus balancing the pressure a little more (the Bernoulli effect). The rear deflector, while having this same effect, is the one that inherently reduces turbulence, which would be coming off of your rig. I need head deflectors on mine, or perhaps a type of hood. My head is so non-aerodynamic. Also adding that the deflectors have everything to with pressurization, the inlets have everything to with inflation... airlocks would be aiding the inflation, and maybe some deflectors on the arms (and angled on the thighs perhaps?) would aid in pressurization. Turn that GTi into a whole new beast."¯"`-._.-¯) ManBird (¯-._.-´"¯" Click Quote Share this post Link to post Share on other sites
LouDiamond 1 #10 July 9, 2003 While it sounds like a good idea I think the whole idea is to reduce drag as much as possible. What I think your trying to do is create in essence what the crossbow was known for and that is for being floaty but with low forward speeds. After having talked with Jari and flown with him I am convinced that if you want lift you need forward speed which means you want less drag in order to go forward faster. I think removing the mesh will do little to improve your performance and may even cause deformation as chuck mentioned. Even if you could keep the cells fully pressurized all the time your vertical descent would more than likely increase snce it would require more pressure to force air into the cells unless the cells where open at the other end,like a parachute. I believe jari said they tried this and it didn't work. I saw 2 of the prototypes Jari is playing with right now and Kevin jumped one of the suits and while far from perfect, I think they are moving in the right direction."It's just skydiving..additional drama is not required" Some people dream about flying, I live my dream SKYMONKEY PUBLISHING Quote Share this post Link to post Share on other sites
ManBird 0 #11 July 9, 2003 QuoteEven if you could keep the cells fully pressurized all the time your vertical descent would more than likely increase snce it would require more pressure to force air into the cells unless the cells where open at the other end,like a parachute.Do you mean inlets across the "nose"? Because a parachute's cells definitely aren't open on the "other end". A "nose", or inlets all the way across the bottom definitely would do no good (that's why the inlets are in the sleeve on the S3), and would just deform the wing. I'm not talking about major transformation, I'm simply talking about allowing the air to flow into the wing faster, and then stay there. The amount of inflation and the profile would not change at all. As evidenced by the Skyflyer 3, more air flowing into the wing, faster, allows for more inflated and pressurized time throughout your flight, thus getting you into the "spot" faster, and holding you there longer. It's just that if you do slow down enough, like after a swoop/dive, you sort of hit a wall because not as much air continues to flow in. Air escapes, thus losing pressure inside the wing, which results in greater pressure on the wing from the outside, which pushes the rest of the air out, totally deflates the wing, now we lose pressure on top of and under the wing, and then forward speed goes, and therefore lift goes, and then you explode. OK, so you don't explode, but does the prior sound familiar? It's also what happens when a canopy collapses. Airlocked canopies, while not completely collapse-proof, have a much better chance of staying inflated and therefore pressurized, therefore giving you a sustained flight... even at slow speeds, be they horizontal or vertical. Plus, I spelled repercussions wrong."¯"`-._.-¯) ManBird (¯-._.-´"¯" Click Quote Share this post Link to post Share on other sites
kevin922 0 #12 July 9, 2003 btw manbird, you don't need to cut the mesh to get access to the cells -- if you're interested in the glo stick thing i actually went on the inside of the suit to get to the cells. Kevin p.s. blair - oxyclean and 4 washes later you can barely tell ;) Quote Share this post Link to post Share on other sites
TB99 0 #13 July 9, 2003 I was just about to type something along the lines of what Lou said when I read his post! He said it before me, but here's my words ... I don't think it'll be any floatier, I think it'll be worse both vertical and horizontal. You will create more drag with more air flowing thru it. More drag = less forward speed and we all know that it is the forward speed that makes our vertical decent slower. The way to get air to flow into the wing "faster" is not by making a bigger hole, but by flying forward faster. Just my 2 cents, and I know Lou just said something like that too, but he woke up earlier than I did I'm pretty much done with this conversation ... curious to hear what Robert says. Trailer 11/12 was the best. Thanks for the memories ... you guys rocked! Quote Share this post Link to post Share on other sites
TomAiello 26 #15 July 9, 2003 QuoteThe problem here is that I don't think you need any more inflation in your wings. Crossbraced parachutes of today have incredibly small air inlets and remain very pressurized. What we strive for is minimal drag while allowing just enough air in to maintain optimum pressurization. If there was a way to encourage faster initial inflation without sacrificing flight characteristics, it would be extremely useful to some folks. Achieving full pressurization even a second sooner (from a zero airspeed launch) would decrease the required vertical distance (to begin flight) by as much as 120 ft (if that's the difference between flight at 4 and 5 seconds, for example). For a superb flyer, who could theoretically begin flying in 3 seconds, an extra second would gain around 60 feet of vertical--meaning that you could launch cliffs that couldn't even be done with normal slider down gear (say 80 vertical feet if you had cajones made of some stainless metal), and outfly them to gain enough vertical drop to open.-- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com Quote Share this post Link to post Share on other sites
SkymonkeyONE 4 #16 July 9, 2003 In that instance, Tom, I think that valves on the bottom of the wings, just like on modern BASE canopies might work. I would figure that Robi and crew would have been messing with that by now. Peace, Chuck Quote Share this post Link to post Share on other sites
ManBird 0 #17 July 9, 2003 QuoteIf there was a way to encourage faster initial inflation without sacrificing flight characteristics, it would be extremely useful to some folks. Achieving full pressurization even a second sooner (from a zero airspeed launch) would decrease the required vertical distance (to begin flight) by as much as 120 ft (if that's the difference between flight at 4 and 5 seconds, for example). For a superb flyer, who could theoretically begin flying in 3 seconds, an extra second would gain around 60 feet of vertical--meaning that you could launch cliffs that couldn't even be done with normal slider down gear (say 80 vertical feet if you had cajones made of some stainless metal), and outfly them to gain enough vertical drop to open. Exactly. I'm thinking a whole new realm of objects. Not that I'm jumping any right now... but I'm working on it."¯"`-._.-¯) ManBird (¯-._.-´"¯" Click Quote Share this post Link to post Share on other sites
TomAiello 26 #18 July 9, 2003 I don't have a technical knowledge of the aerodynamics, but it appears to me... The inlets on a wingsuit are already on the bottom skin, rather than the leading edge (which is occupied by your arm or leg), and are already in a position roughly equivalent to the secondary inlets on the bottom skin of a BASE canopy (which are placed either just forward of the B line attachments, or midway between the A and B attachments). I'm not sure that anything other than a large one way valve covering most (or all) of the bottom skin of the wing is really going to decrease pressurization time. The only real good way to decrease pressurization time that I've heard is to somehow "preinflate" the wings. Picture a wing shaped balloon insert that you put inside the wing, then inflated prior to launch. That way, the wing would be inflated at time zero. I asked Robi about this a while back, and he pointed out that for deceleration purposes the wing is already expanded at time zero (since you stretch out your arms and legs to pull it taut), and that any additional gains to be made would come at great cost. Specifically, larger inlets would degrade flight performance, and that some kind of preinflation technique would require a complex (hence prone to failure) purge valve to be used prior to parachute deployment. Still, I'd love for someone, somewhere to work it all out, then sell me a suit that starts flying immediately upon launch. Maybe that powered Skyray prototype...-- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com Quote Share this post Link to post Share on other sites
ManBird 0 #19 July 9, 2003 Yeah, makes sense. One of the theories, as mentioned in the first post, would that it may cause the suit to become floaty... looks like others believe. I don't think it would distort the wing nearly as much as is claimed on here, especially since your body is acting as a rigid frame to prevent this. I don't think the wing can "overinflate", thus increasing the profile and inducing drag, thus reducing performance. I just think there would be quicker inflation. Still interested in knowing if they've played with airlocks at all. It can't be denied that an inflated wing performs better than a collapsed one. Kevin: Thanks for the tip, I'll take a look at where the GloSticks may be inserted."¯"`-._.-¯) ManBird (¯-._.-´"¯" Click Quote Share this post Link to post Share on other sites
kevin922 0 #20 July 9, 2003 QuoteYeah, makes sense. One of the theories, as mentioned in the first post, would that it may cause the suit to become floaty... looks like others believe. I don't think it would distort the wing nearly as much as is claimed on here, especially since your body is acting as a rigid frame to prevent this. I don't think the wing can "overinflate", thus increasing the profile and inducing drag, thus reducing performance. I just think there would be quicker inflation. Still interested in knowing if they've played with airlocks at all. It can't be denied that an inflated wing performs better than a collapsed one. Kevin: Thanks for the tip, I'll take a look at where the GloSticks may be inserted. I'll take a picture of it.. on the gti there is a very small section of stitching between two larger sections (i know my descriptions suck) it is basically a horizontal line of stitching between two vertical lines. i just cut the horizontal line it is just wide enough to get glo sticks in. It doesn't affect the flight too much though blair said he saw them bouncing around .. i don't fly the GTI enough to say it made a huge difference in performance - i know it was a stable flight. I had used some office supplies (i call them aligator clips) to close up the opening -- pyke jumped the suit with those clips on.. when I jumped it i took them off.. can't say it made much of a difference there either. Kevin Quote Share this post Link to post Share on other sites
outrager 6 #21 July 9, 2003 Yo ! QuoteStill, I'd love for someone, somewhere to work it all out, then sell me a suit that starts flying immediately upon launch. Maybe that powered Skyray prototype... Well, the suit won't really start flying until it accelerates beyond the stall speed, and by then it's well pressurized anyway. I'm curious if mylar ribs will make any difference on BASE exits, but my gut feeling is it'll be negligible. I should have an opinion later this summer. I believe the inlet size is practically irrelevant. bsbd! Yuri. Quote Share this post Link to post Share on other sites
VectorBoy 0 #22 July 9, 2003 QuoteThose things on your sleeves are deflectors, not inlets ... they make the airflow over your wing smoother instead of a twirly tornado. Smoother slipstream; they don't do anything for "pressurization." These little pockets on the sleeves are vortex generators that keep the outer wings boundry layer airflow energized.... They create little tornadoes on purpose on the first part of the wing. This helps smooth the airflow across the middle and trailing part of the cell. The part that really changes when you move your arms around. Quote Share this post Link to post Share on other sites
LouDiamond 1 #23 July 9, 2003 QuoteI'm curious if mylar ribs will make any difference on BASE exits, but my gut feeling is it'll be negligible. Jari's suit and the other prototype he had with him have mylar inserts in the wings and the overall effect doesn't seem to be that great, according to Jari, the pull sequence is a bit more tricky due to the inserts in the wings and there are some tail issues that need to be tweaked but I think it is a move in the right direction that may help all types of wing suit jumping."It's just skydiving..additional drama is not required" Some people dream about flying, I live my dream SKYMONKEY PUBLISHING Quote Share this post Link to post Share on other sites
ManBird 0 #24 July 9, 2003 Hey, Yuri, any theories on airlocking? I think they could genuinely accomplish what is trying to be accomplished with the mylar... keeping the wing's shape. I do think the mylar would help with exits a wee bit, as you get a little more surface area to catch earlier on, but the difference for BASE exits would probably be marginal."¯"`-._.-¯) ManBird (¯-._.-´"¯" Click Quote Share this post Link to post Share on other sites
outrager 6 #25 July 10, 2003 Yo ! Airlocks are completely useless here. The wing holds its shape just fine as it is after the first 2 or 3 seconds. It also needs to deflate instantly at pull time, this is where airlocks would be a problem. Mylar ribs idea is to have the wing somewhat pre-inflated as you step off. It might be marginally beneficial for BASE exits, that's still to be seen. bsbd! Yuri. Quote Share this post Link to post Share on other sites
