LeeroyJenkins

L/D (not GR, who cares about it, really, other than people who don't know the difference) changing 3.0->3.5 is actually a HUGE deal. Look what the 20% change 2.5->3.0 did - we have much more massive dives and much more massive flares, and faster starts in BASE, enabling jumps that have not been possible before. With L/D = 3.5 (almost the magic L/D of 3.567), we'll have mind-blowing flares and dives, the energy buildup and retention will improve dramatically (as I wrote in the Wingsuit Research thread, the dependence of these things on L/D is not linear, it's more like exponential). As well as new jumps opened in WS BASE. I've offered my device several times, but no one is interested, although it almost happened with one world champion (I don't remember why it didn't happen - he was seemingly interested, but either I had to go, or he had to go, or what, don't remember.) People just don't understand it, and it seems weird to them. "I have a Flysight, why would I jump this weird thing?" They can have many thousands of jumps and several decades in the sport, but they don't understand the difference between GR and L/D. But surely WSMs can build a vane for their smartphone or smartwatch and use the tool to quantify wingsuit characteristics? But they don't do that, because... CoW. (and I bet they don't understand the diff between GR and L/D, either) Why do you think 3.567 is the magic L/D ratio for wingsuit flight? What parameter of the wingsuit flight is that magic number for?

Sure, It really isn't a big deal. What is a big deal is him complaining about the main stream media manufactures marketing techniques while aggressively promoting his product based in junk science.

Wrong. 3.0 (+/- hundredths, maybe) L/D is not determined by speaking with folks, it's determined by rigorous calculations like in the link, or by real wingsuit instrumentation like L/D Vario and L/D Magic. Isn't peddling your product against the rules? Rhetorical. The Forum Rules: 1.No personal attacks. 2.No jokes about or references to pedophilia. None. 3.No advertising in the forums. 4.Post to the correct forum and stay on topic.

I'll show how it's done. Let's take this track from Paralog as an example. https://www.paralog.net/ppc/showtrack.php?track=26916 In 3D view, https://www.paralog.net/ppc/showtrack3D.php?track=26916 we see that the flight is pretty much exactly downwind, with the wind of 49km/h (26.6kn) right on the back (257 degrees). So, we subtract 49km/h from horizontal speed. Let's use the above mentioned WSE trick to find L/D in extrema points of Vx (in these points, according to WSE, L/D is equal to air glide ratio; in arbitrary point, L/D != GR). We see several minima/maxima in Vx: t=33.0s, Vx=146, Vy=48, L/D = 3.04, ground GR = 4.06 t=42.0s, Vx=151, Vy=53, L/D = 2.85, ground GR = 3.77 t=59.0s, Vx=130, Vy=49, L/D = 2.65, ground GR = 3.65 t=74.4s, Vx=132, Vy=51, L/D = 2.59, ground GR = 3.55 t=87.0s, Vx=122, Vy=50, L/D = 2.44, ground GR = 3.42 So we can clearly see that this is nothing but gaining tremendous speed before the window and slowly (very slowly) flaring it into a better GR. L/D starts from 3.04 and continuously falls down - the angle of attack is slowly increased, L/D is decreasing. Average GR in the window - 4.195, but this is not L/D! L/D is 3.04 max. We can analyze any Paralog or Skyderby track like this and see that max L/D is never higher than 3.0 (plus/minus small change). Besides using extrema points, one can use general formula that relates L/D and GR, which is derived from WSE: L/D = (GR + z)/(1 - GR*z) where z is dimensionless ratio z = ax/(g - ay), ax is horizontal acceleration, ay vertical, g acceleration due to gravity. GR here is glide ratio relative to air, not ground! Also, when z = 0, L/D = GR, as mentioned above. L/D is like a inverse of coefficient of friction: the latter depends only on smoothness of surfaces and has a finite minimum value (coeff. of friction can never be zero, excluding quantum phenomena like superfluidity). Same with L/D - it's a finite value from 0 to (for current wingsuits) 3.0 (+/- maybe hundredths). No one can fly current wingsuits with L/D higher than this max value! Glide ratio is a different animal altogether, it can be anything from -infinity to +infinity. Same as a skateboard temporarily moving horizontally or going up - it doesn't mean the coefficient of friction turned zero or became negative! L/D is a true aerodynamic finesse parameter, GR is for these bogus competitions with their bogus numbers (5:1, 6:1, etc.) L/D for the win!!! Did you just use your own equations to prove your equations right? Also, everyone note, the reason yuri wont answer my question about the limits of wingsuit design is because he knows it will ruin his own argument (or he actually doesn't know) which would be ridiculous since he is claiming to have this revolutionary knowledge.

Where's the graph? Don't dodge the question. What is the number one limiting factor in wingsuit design?

Dude, there are so many things wrong with your post it would take forever to correct them all. Wingsuit specifically, it seems like you aren't aware there are different kids of suits for speed and distance compititions.... there are. You also never answered my question, what is the number 1 limiting factor in wingsuit design?

Yeah, I haven't made a post in this forum in 8.5 years, since Feb 2010. Dropped by to see if the new generation of wingsuiters would be interested in some old ideas and theories they haven't seen, critical and honest evaluation of WS progress in the past 12-20 years, as well as relatively new and not widely known wingsuit-specific software and instrumentation I developed in the past 5-10 years. While I'm not surprised that those old timers who were generating nothing but noise back 12 years ago (which everyone can see themselves by reading links to my old posts in OP), haven't changed - I'm disappointed that the new generation is absolutely the same. This, unfortunately, only confirms that the wingsuiting is still staying in the state of CoW. My goal was and is and will be to further the wingsuiting by sharing freely my ideas, calculations, software, and critique to nudge the WS R&D - either hopefully by major WSMs, or maybe some creative spirit who likes some idea and makes it a product. Unfortunately, due to CoW, this has failed so far, with no foreseeable change in the near future. My main interests still remain in the area of wingsuit dynamics research, via physics and software. I've got, in meme speak, over 9000 ideas in this area still waiting their time. I'll continue working on them. It's also the area where (unfortunately - "thanks" to CoW) I have no competition and inspiration from others' work (since it's nonexistent). I have no interest in creating physical products or proving anything by winning the competitions. (I just don't give a fuck, seriously.) If anyone is interested in applying scientific methods to competitions, wingsuit design, instrumentation, etc. - post on this forum. (The info and tools I generate based on these discussions will always be public; no "secret coaching".) If anyone wants to start a new WS company and make some innovative products like "superterminal wingsuit", "half-wingsuit (Superman)", wingsuit instrumentation - go ahead, just do it! (Man, I can't wait!) Post on this forum and I'll provide my input as best as I can. By watching WSMs do precisely nothing new and perpetually staying in the state of CoW, swallowing all their marketing BS - we're just wasting our lifetimes. We could have seen so much more in the past 20 years since the beginning of commercial wingsuiting in 1998. If WSMs responded positively (not with immediate rejection and aggression, even bullying) to nudging, critique, freely shared ideas; if they actually used real instrumentation, created for them, to quantify various improvements, instead of feeding us all this marketing BS; if their goal was, too, to maximize their lifetime of being a WSM, use every bit of it to actually take wingsuiting to the next level, not do the "same old, same old" routine - man, I can't even fathom what kind of wingsuits and performance and instruments we would have today! I think it's obvious now that all faith in "old WSM farts" is gone now, they have a proven record of perpetual CoW and 3-stooging. My only hope, in terms of physical products, remains on yet-to-be-born new generation of WSMs. You are so full of shit. You probably didn't expect to run into an aerospace engineer and a mechanical engineer in here that know more about the mechanics of flight and airfoil design than yourself. Let me ask you one very important question. What is the biggest limiting factor to the improvement of wingsuit performance?

I have no idea if wingsuit designers use a scientific approach to design. It would be better if they did, I agree. But Yuri's approach is not scientific and there are many flaws with his methods, not to mention the conclusions he reached. throwing insults and calling wingsuit manufacturers names because they don't implement his (unproven) ideas is not very scientific...it's immature. Wingsuit manufactures do use science to design their suits. His entire premise is wrong. That's why he is laughable on this topic.

Not interested. Skydiving and BASE are just my hobbies. I put my ideas and software "out there in the wild" (i.e. here and some other similar forums, I'm not on social media and never will). If no one is interested, not my problem. I feel absolutely no burden, no obligation to anyone to prove anything. The ideas and software I make have value for themselves, once released in the open, they have their own life. No one interested? Fine, at least, they are just electrons, no need to store them in warehouse like physical products and sell under their value. Ideas are very hot these days in almost all areas of technology - propose some idea somewhere on the internet - and next day there will be 10 startups making it a reality. Not in the world of wingsuits. There it remains... CoW. I don't have to prove anything to anyone. Literally not how science works, the burden of proof is on you. Also I called this one, just trying to sell your app using aggressive marketing.

While "Agility, Safety/Usability, behavior and stability" are, no doubt, very important for certain types of flying (f1.0cking?), I'm talking about cutting edge. I'm talking Ferrari, not grandma's PT Cruiser or golf cart. A golf cart has a lot of specific features, like very tight turning radius (agility), safety (slow), usability (no doors), and stability (heavy batteries on the bottom and lightweight roof). A lot of research went into designing a golf cart, and it's respectable. But I'm clearly talking about the cutting edge, pushing wingsuits to fly even farther. Or faster. Or longer. (Is anyone even lobbying the idea of using 3 different suits, for each discipline in competitions - speed, distance, time - which will foster the development of interesting - and useful - new designs?) For some reason, WSMs (WS manufacturers) stopped working on maximizing max L/D somewhere around 2010-ish, when it became clear that T-planform is the winning formula and inlets must be on the bottom surface and scooped. That's it, nothing substantially changed since then. For almost a decade now, max L/D is pegged at about 3.0 (maybe - maybe - some pterodactyl-like pilots wearing superthin/integrated rigs, thin shoes, no or very thin helmet can do 3.1-3.3, but that performance bump is not wingsuit's merit). Because WSMs stopped trying. And because they don't use the readily available precise scientific instruments for measurements of aerodynamic parameters. And because they refuse to use even freely available ideas spoon-fed to them on the forums. I propose to call this passiveness of WSMs in the past 12-20 years (and continuing into the future) CoW - short for "Cow of Wingsuiting": Instead, they all engaged in Godzilla Marketing tactics with fast upgrade cycles (multiple models, upgraded every year each) and marketing speak flashfloods filled with superlatives and piles of BS disguised as chocolate nuggets. It works for them - wingsuits are flying out of the factories like hot pancakes, $1.5-2K each! (They've also raised the prices unilaterally to compensate for the new players on the market taking their slice of the pie.) This clearly shows lack of understanding where the better dive/flare came from. It didn't come from the genius WS designer's brain, from enormous effort of creating new revolutionary designs... it came automagically with the increased L/D (from mid-2's to 3.0) - which, in turn, is a result of a mere surface area increase - and from better ability of T-planform, compared to classic split arm&leg wings planform, to change the pitching momentum at will. (And T-planform was found by random trial and error, throw stuff at the wall and see what sticks.) This diagram posted a decade ago: is a polar graph of current horizontal and vertical speeds after a BASE exit, in constant flight configuration (mode), for various L/D's, from 0.5 to 3.567. It clearly shows the dramatic effect that increasing L/D has on gaining more kinetic energy in a dive and retaining it longer and converting it to potential energy more efficiently. (Note that this is not even a flare, this is a natural planeout after BASE exit. Real flare differences are even more dramatic.) Let me make this analogy. L/D is very much like an inverse of coefficient of friction - the lower the friction, the higher L/D. Why? Because if you consider a force diagram of 1) a wingsuit and 2) an object sliding on inclined surface - they're identical! We have weight, then in 1) we have lift L perpendicular to the line of travel and in 2) we have normal force N perpendicular to the surface; and in 1) we have drag D parallel to the line of travel and in 2) we have friction force F parallel to the surface. In 1), we call the ratio L over D as a number (L/D), which is a measure of wingsuit's aerodynamic finesse. In 2), we call the ratio F/N as a number (k) - coefficient of friction. So, by this analogy, (L/D) = 1/k. We know that for object to slide on an incline, the tangent of the angle to horizon must be equal or greater than k. For example, if k = 1/3, then the angle is arctan(1/3)=18.4 deg. This is the same angle as a sustained glide angle for a wingsuit with L/D = 3.0! So, imagine riding a skateboard in a skate park. With a good skateboard with low friction, you can gain more speed going down an incline and retain this energy longer for going up on various tricks. A rusty skateboard will gain lower speed and will stop going up much faster. Same with wingsuits, really. These two factors - amount of speed gained in a dive and the more efficient conversion of it into gained altitude - are multiplied and as a result, flare is quite sensitive to increasing L/D ( = decreasing k). That's why a relatively small (50% from wingsuits of early 2000's or 25% from 2005-ish) increase in L/D resulted in massive improvement of dive and flare. Plus, the T-planform advantage in pitch control, which was copied by every other WSM. Why don't WSMs show the exact changes of this "research by flying"? Before/after. And did they quantify the before/after change? Or it's just marketing blah-blah-blah? Why didn't WSM's try various ideas offered to them for free on the forums? The non-zero angle of incidence for both arm and leg wings? ("superterminal wingsuit", link in OP) I tried it ca. 2007-8 with the arm wings on my Phantom-1 and Vampire-2, it was promising, but I couldn't quantify it, because at the time I didn't have the instrumentation. I did it by sewing a second set of tabs going from armpits towards crotch, not along the sides (which is zero AoI). This is only possible with planform designs of old wingsuits with separate arm and leg wings, and for the leg wing, it requires Vampire-style leg wing with its own leading edge. Because... CoW Half-windgsuit with leg wing only? I tried it many times, starting with flying just the pants of my Prodigy back in 2005-6 and the advantages in speed were obvious. Also, eventually cut both P-1 and V-2 in half and flew the leg wings. Also, cut my V-4's arm wings completely after the zippers broke, and flew it like a Superman, with arm(s) stretched forward. Flew it in Eloy, Perris, San Diego, Lodi - no one is interested. I'm sure if some WSM made such a half-WS, people will say, "wow, this is awesome, the speed is just ludicrous!" (it also naturally puts L/D close to 1.4 - the optimal for max horizontal speed) Because... CoW Why no WSM is using real wingsuit instrumentation, not just GPS/Flysight which can't determine aerodynamic parameters? Because... CoW The list of ignored ideas is very long and this post is already long, so I'll stop for now. It's hopeless anyway, as I learned over the past 12 years. The Solar System - at least in WS innovation sense - is a very lonely place, it turns out. You are so full of shit, explaining why would be like talking to a brick wall. When you come up with something real, revolution, and can prove it, come back and I'm sure people will listen. For now you seem like an old man yelling at a cloud.

Alex Jones must be a buddy of yours. I have seen them in the news but know very little about him. by the way, what do you think of the grand jury that's been empaneled against FBI Personnel who have been involved in the Russian collusion bullshit? You literally use his talking points. I'm not aware of a grand jury but that sounds great. Get the criminals out of their positions of power. I'm not like you, my team is the United States of America and the people that compose it. Not a person, or party.

Hey rush, wish Alex Jones off Twitter who is going to tell you what to say about all of this?

Sigh. You treated C_l and C_d as constants. Which means if you use the equations that you used in the beginning: D = 1/2 rho * V^2* S *C_d Then yes, setting V to 0 will result in D = 0. Is this why you think the drag polar is invalid? Because of D = qSC_d? Also, you said in the post: ***We have 2 equations for 3 unknowns (k and Cl, Cd). But note that if we combine k with the Cl and Cd into "adjusted" lift and drag coefficients (no longer nondimensional) Which is incorrect. k is known - it's 0.5*rho*S/m which is constant (rho = approximately 1.225 kg/m^3). So I'm not sure why you had to condense them to yet another set of coefficients. It's understandable why D = 0 if V = 0 when you use that equation, but this drag term is not a constant - it's a condensed set of coefficients itself and is itself calculated with another equation. The drag polar was not derived from the equation you started with, which is why you got a different result. The equation you started with has been extremely simplified. The V in this equation also denotes airspeed, and GPS measurements only measure ground speed. Please refrain from personal attacks. Dude, it's not worth the argument. The best we engineers can do is to make sure people don't buy into this guys nonsense. He isn't going to reinvent unpowered flight. He for sure isn't going to reinvent unpowered flight with an infinitely variable wing.

You're speaking to a mirror again John! You do this every day. Projection projection projection. That's all you got Rush you might as well be a flat earther and think haarp is a mind control station at the rate you’re going. Also it’s a mental disorder called narcicism. Trump has it 100%.

Lol, fighting back is also called obstruction when your the boss of the investigating department.

well, we now have a post that goes against a person on Speakers Corner. Seems like a flagrant disregard for the rules? And form a moderator no less. Holy shit guys, he has gone full trump. Rush is parroting trumps tweets. Classic trump tweet ending, make assertion, stick a question mark at the end, hope fox and friends tells him what to do. If this isn't full blown trolling and lack of personal opinions I don't know what is.

CFD for now, as applied to wingsuits, is just a toy producing pretty colorful flow pictures. (See #2, 4, 7, 8.) They miss the most important first step: validation of simulations vs. real wingsuits. They get unrealistic max L/D (I've seen 4.0 and higher), which shows that their results have unknown (possibly no) relevance to real wingsuits. Their main purpose is to make pretty pictures. Give me a break, are you at least a mechanical engineer or aerospace engineer? So how long till you start selling your product/data? You marketing campaign seems to be off to an aggressive start?

Here is a video for you. Take from it what you want. https://www.youtube.com/watch?v=zCM-eAekMCg Dammmnnnn those Safire openings were slow and crappy.

Just removed the sewn on part. I used a jav D bag with a sky snatch for hundreds of jumps. It is no issue.

To the best of my knowledge, true L/D and polar measuring devices I invented have never been used by anyone in Solar System other than the author. Smartphones and smartwatches are available. Apps (even free) are available. Telescopic poles are available. Simple materials are available. But no one has ever been interested in spending an evening or two to build a vane. 12 years since the idea publication, about 10 since Z-Device and Analog L/D Meter, 5 years since L/D Magic launch in Apple appstore, 3 years since free L/D Vario app, available on 4 platforms. Nothing. Nada. Imagine similar situation in any hi-tech industry (aerospace, cars, etc.) if someone invents the theory and devices to measure critically important performance parameters, and for 12 years they do this (and will continue for X more years): Hartman Rector is the only one who "gets it". Using polar curve deduced either from GPS data with wind correction, or from L/D Magic and L/D Vario, one can not only model their flights with arbitrary conditions and control inputs (to evaluate a prospective WS BASE jump, for example), but also model competitions for speed, distance, time to find the winning strategy (and it's all can be simply done in Excel, like Hartman does, no special software needed! although Wingsuit Studio can be used for piece-wise modeling since it only supports constant flight modes). Even when I mention 1.4=sqrt(2) (recently corrected to 1.3) as the best L/D for max horizontal speed and ask the competition champions what's their glide on speed runs and get ~1.6 (which is, more or less, 1.4 + wind push), I get a blank stare. They can't fathom that these things can be determined by scientific research, without leaving the couch even, and has been done 10 years ago! As I said before, unfortunately, despite all the guerrilla/gorilla/Godzilla marketing BS we get to eat these days, the wingsuit industry has been, essentially, in a coma since its birth 20 years ago. No wingsuit manufacturer knows the most important flight characteristic of their products - max L/D - or how to precisely measure it. And a lot of the research listed above is also just BS, the vehicle for students (or even professors!) to get their diploma/get funding and be out the door: Some research is genuine (Geo's, who was also a WS BASE jumper), but has errors or fallacies in it, stemming from aeronautical educational background, which puts emphasis on powered airplanes, not gliders. These fallacies get perpetuated and we get dangerous errors unintentionally disguised as scientific nuggets. As far as my performance numbers, I precisely measured my max L/D in Phantom-1 (2.15), Vampire-4 (2.75), and Aura-2 (2.9). I'm not fit, so for the same suits I would expect 5-10% higher numbers for athletic body build. PS. For PF tracksuit, I got 1.4, and for V-4 with cut armwings, in traditional tracking position/arms along the body, or in "Superman mode", with arms stretched forward, I get about 1.5-1.6 (but much faster than tracksuit). Unfortunately, I didn't have time or energy to pursue Superman flying more, because I always skydive my BASE canopy, and openings after Superman are really hard; and I don't have a physical strength to hold Superman position for long - the forces that try to bend you like a banana are incredibly strong! If anyone sees me at their dropzone, ask me, I can give you the leg wings of Phantom-1, V-2, or V-4 to try this "superterminal" flying. Where is your 3D flow simulations and modeling?

Ah, ha!!! That explains why his desk in the oval office is always bare of papers!

I know of several cases, besides mine. 1. Geo Robson from Switzerland, did some research on wingsuit dynamics, similar to Wingsuit Equations. Circa 2009-10. 2. Some student from Israel whose research paper I found by a web search. He was making small crude wood/plastic models of wingsuit and studying them in a small windtunnel. Circa late 2000's. 3. Someone wrote a paper on stability of Apache wingsuit using CFD simulations. Circa 2010-ish. 4. Icarus Project linked above. 2015-current. 5. Harman Rector did and does research on wingsuit dynamics using Wingsuit Equations expanded to 3D, using his flights and GPS data to first extract sustained polar curve, then using it to fit other flights and evaluate the feasibility of prospective flights. Recent 2 or so years. If there's anything else, publicly available, I'd love to know. Other than Hartman's 100% solid work and Geo's somewhat confusing work, the rest is just academia-type diploma-level kind of stuff (write a diploma paper and forget about it). To this day, I don't know of any attempts, other than mine, to use L/D Magic or L/D Vario apps (or their own apps) with a smartphone or smartwatch on a vane to accurately measure wingsuit flight characteristics. Or to use a Pitot tube the only proper way - on a vane, on a long stick. That manufacturers never showed any interest, never inquired about available L/D and polar curve measurement methods, shows that they don't do any serious scientific research to improve wingsuits. (It's like someone invented a Pitot tube, but no airplane manufacturers were interested - they continue developing their planes using a flapping scarf on a pilot sticking out the window: "this plane seems to be faster!". Or a car manufacturer never using a speedometer - "I simply watch the clouds of dust the tires kick!") Godzilla Marketing, not science, is their main weapon. But I would absolutely love to be proven wrong. Lol, ok. Not being publicly available =/= the research hasn't been done.

There has been scientific research done on modern wingsuits, saying there hasn't is absolute BS and an insult to the aerospace engineers that help design these suits.

I really like my Outlaw Lite. I am also pretty new to the base and land in a lot of small areas. Lots of sinking in approaches. I have head great things about the Hayduke, I think if I start doing more slider up stuff I will get one. If you are used to flying a base canopy like the outlaw the epicene has a pretty solid flare.

Or they simply think "left" = "bad" and they figure they are not as bad as David Duke. It would not surprise me to hear, for example, that some of the right wing posters here consider David Duke to be a liberal progressive, because they are bad too. Is that wrong? Of course it is. But you cannot 'fix' people's misconceptions when those misconceptions are what they use to justify their entire worldview. You can sure try, might take a life crisis, but it is possible.