yuri_base

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Posts posted by yuri_base


  1. LeeroyJenkins

    the second they start they already have a mathematical predetermined steady state. This is shown by your graphs.



    What? I don't understand.
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  2. Okanagan_Jumper

    I'm not sure what the incentive would be for anyone to produce a $200 wingsuit, given there would be no profit in doing so. Wingsuit manufacturers are not philanthropists. They exist to make money.



    If foam wingsystem, consisting of 2 foam arm wings and one foam leg wing, mass-produced in China in standard sizes S, M, L, XL, and belt attachments that accommodate wide range of body sizes, is manufactured for production cost of $50, I don't see why it can't be sold for $200 for a nice $150 profit. There's no need to make a wing suit, per se - it's a modular wing system*. And thus there's no need for so many body measurements, the wing mounts will be infinitely adjustable.

    But the main idea is that it's the thing that anyone (even with hands growing from the ass, like me) can build one using simple materials costing maybe $100 (not in bulk) and simple tools like a hot wire to cut foam, some ZP to wrap and glue to the foam, and a bit of simple sewing like sewing in attachment belts or some zippers (definitely, orders of magnitude less complicated than sewing all those ribs in wingsuits!). And it will be open source, anyone can implement their ideas as they want, and make a system for themselves, for cheap. And it will be modular - any wing can be swapped for a different airfoil profile, for example - and with things like AoI adjustment, possibly even leg wing forward/back shift, etc.

    Even with my poor DIY skill, I was able to build a nice high-lift airfoil leg wing, with nice leading edge (about 1ft long) from knee to knee, smooth, without any "pillowing", with sharp trailing edge, and zippered attachments (using a simple household Singer sewing machine, not a lot of sewing). Started building arm wings, but didn't have time/energy to finish. It's all dusting somewhere since about 2008. Someone else will follow. I hope. Perhaps, a new WSM will be born from this, or several even. Anyone is welcome to do so.


    * it can be jumped even naked!
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  3. BryanCampau

    A few very smart people built a fully flyable wingsuit tunnel that can vary speed and angle. I’d love to know why you feel this isn’t revolutionary and could lead to future advancements in suits? It would certainly do much more than flysight or jumping a vane with a cellphone could do.



    1. Wingsuit tunnel (WST), to match each pilot's max performance, will need to adjust both angle and air speed. For example, if one's max L/D is 3.0 (and they don't know that yet), and flight mode corresponding to that is 90mph/30mph (and they don't know that yet), they need to make a lot of attempts with 2 independent variables to finally arrive at the angle of 18.4 degrees and air speed of 94.9mph. Even if one of these is wrong, the pilot will simply either sink to the floor, or float to ceiling, or hit the front mesh with their head, or back one with their feet - or combination of the four. Even if the tube is made with variable diameter and angle (like a horn), the exact combination of L/D (place in the tube) and airspeed will be hard to nail.

    [inline Horn.png]

    The reason it's so easy currently in WST to fly is because it's set for ridiculously low L/D = 1.67 (that's L/D of the wingsuits of the 20th century!) to give a lot of available range to the flyer, make acrobatics easier, etc. For the top L/D, there will be zero range, both in angle and speed. If will be extremely frustrating, and time consuming, and time is 1200 Euros per hour.

    2. Only few chosen ones (with unlimited time in WST for free available to them) or millionaires will be able to spend hours studying their aerodynamics in WST. For the rest of us, these results won't be as useful as their personal results. Personal data for those who can't afford hours in WST can only be obtained from jumping.

    3. In WST, one cannot feel as natural as in real flight, and thus the results won't translate well between the two. In real flight, one has visuals of terrain or clouds zooming in in starfield effect ("accuracy trick") and sensation of speed relative to terrain or clouds; in WST, it's all stationary and all one sees is safety mesh and floor.

    4. In WST, flying is done without a rig. Although the chosen ones can make a rig mockup and fly with that for closer match to reality, those who pay for their time will be flying "naked" (even with a mockup, it won't necessarily exactly match their personal rig). Without rig, aerodynamic data will be skewed.

    5. If a platform is used to measure forces like in real research wind tunnels, body position will be affected, as it's hard to reproduce exactly the position from the real flight, esp. when the pilot is tired lying on the table while being prepped. Also, it will be hard to precisely subtract the effect of the platform itself from measured forces.

    6. Experiments with smoke to determine laminar/turbulent areas, can be done - and this is an advantage over real flight - but as always, it'll be used mostly for making pretty, self-promotion pictures.

    7. Vane with a smartphone/watch measures real, personal data, in real flight. And it's free. And it measures L/D and other aerodynamic parameters in real time, no need to fiddle with the fan speed and angle, like in WST.

    8. WST or research tunnel, in right hands, can provide some scientific data. The problem is, the tunnels so far have been in wrong hands, used not for science, but for self-promotion and pretty pictures, as well as a cash cow as with WST. There are several examples of such use over the years, including the famous Jari Kuosma's pic in the tunnel back in early 2000's, set at AoA of about 60 degrees, with L/D of probably 0.5, LOL.

    [inline Jari.jpg]

    It will take many more years before we see real science done in WST. Vane is available right now, it's in everyone's toolbox and pile of scrap materials, and the app is free and runs on any device, even cheap, no cell-service necessary, Android phones that can be found as low as 20 bucks (I have several that I use as WiFi devices - Huawei Ascend XT2, $50; Motorolla E4, $40 - fantastic devices!)

    BryanCampau

    You seem very opposed to listening and replying to anything that doesn’t promote your own work.



    Not at all. I specifically created this thread so people can share their own research, theories, formulas, data, thoughts, ideas, and works they found on the internet. I'm all ears. However, so far it's just me presenting value here, the rest, unfortunately, is just unsubstantiated noise. Everybody is welcome to post here their valuable signal. I can't wait!

    To anyone who feels it's just me talking here and it's all about me and my apps, fill this thread with your own valuable contributions and my contribution here will not seem to be "in the face" anymore.

    I do not reply to silly questions like "does WSE use Bernoulli or Euler" because WSE derivation is published in OP and anyone can read it and see that there's no Bernoulli, nor Euler in the derivation. And many other equally silly questions. As well as these silly attacks about my burden to derive and to prove, while the derivation and the proof is right there, in OP!

    Anyone who claims to refute WSE or other work, needs to do so with solid argumentation on the same level, i.e. mathematically.

    BryanCampau

    A true airspeed indicator that doesn’t rely on gps is great, but not practical given you need a large attachment to get the reading.



    C'est la vie... c'est la vie! As I said in the thread about airspeed indicator, this is the only way. It doesn't mean the whole Otter will be filled with people with sticks, or there will be f1.0cks with a bunch of sticks, but one or two thoughtful and experienced jumpers on a load doing solos is not a big deal, as my test jumps in many places (Ranch, Zephyrhills, Eloy, Perris, San Diego, Lodi, etc.) show. Let alone in BASE, of course. It's not uncommon these days to see people jumping these ridiculously long camera sticks on the helmet - even two, both front and back! People accept inconvenience to achieve their goal to post their pretty face in flight on social media, I see no reason why people who are interested in studying the flight cannot have similar inconvenience.

    I've done quite a number of jumps with vanes, both skydiving and BASE, and it's no big deal, really.
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

    Jari.jpg

    Horn.png


  4. And as I said before, I much prefer building ephemeral products (electrons, ideas) to building physical ones, since physical ones can easily be shamelessly copied, they might not sell as well as was expected, and then one has to deal with inventory that needs to be cleared even at a loss, one has to deal with customer complaints, replacements, service... yikes! With electrons (software), it can't be easily reverse engineered (one needs advanced math knowledge to make something like L/D Magic), it can't be shamelessly copied (an app that's exactly the same, will be removed from the app store immediately), can be made in any quantity needed without any effort (there's enough electrons in the world to make any number of copies of the app), it doesn't require a warehouse to store and inventory to clear. Ideas only need a piece of paper, or keyboard, and a timestamped copy on web archive to prove your first, if question arises. Electrons and ideas for the win, at least, for me!

    If someone else good at manufacturing things, having solid grasp of outsourcing manufacturing to China, makes a foam suit for sale price of $200, based on my ideas, I'd rather just release my ideas and pay $200 and get a finished product I didn't have to sweat to make.

    And I firmly believe that someday we'll see a $200 wingsuit/system. Fuck tailoring and all this sewing stuff!
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  5. hjumper33

    why haven’t you designed a new suit yet?



    I'm not good at making physical things, I'm much better with theoretical research, ideas, and software. Humans specialize in things they do best, and that's how humankind reached the levels it reached, by specialization, one cannot do everything. A surgeon, for example, most likely cannot be a good theoretical physicist, as both professions require full dedication. (I, for example, would make a poor surgeon, maybe can do a quick amputation with a chainsaw, though?)

    I actually started building a foam, configurable wingsuit/wingsystem in 2009-ish, with adjustable AoI, wings that can be changed, and distinctly separate leg wing with it's own long leading edge from knee to knee, but never finished it. Long work hours, fatigue, etc. - just didn't have energy to concentrate on it. But I've accomplished reasonably lot of other things that I'm better at.

    The questions like, why haven't you designed a new suit, why haven't you won all competitions, why aren't you the fastest man in the world, why don't you trim trees in the closest proximity ever, they are the lowest level one can ask in a discussion, turning the subject from abstract to one's inability to do everything and be everywhere at the same time. Elon Musk is good at generating ideas and managing other people to implement them, but he can't build an electric car or a rocket himself using his hands, that would be a very inefficient use of his genius.

    Turning the question around, why haven't someone else created WS instrumentation, theory, software? Why haven't even WSMs used the software that was already built for this purpose? Why WSMs haven't even tried the ideas somebody posted for them on this forum? Why haven't a surgeon created a HUD built-in into human eye?

    I will be posting the details about foam suit/system soon, so anyone can continue this open source project.
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  6. aonsquared

    avoid engaging experts who can actually see through your claims.



    I'm still waiting for experts to rigorously, mathematically, with formulas and data (not by just wapping their mouth) show that WSE are incorrect, accelerometer-on-vane principle is incorrect, WS instrumentation based on WSE is useless and outputs bogus data, flight decomposition/analysis is useless or wrong, etc. etc.

    I've been waiting for 12 years, and counting. Anybody is welcome to actually refute my claims.
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  7. aonsquared

    ***I carpet-bomb with formulas until naysayers drop dead from exhaustion.



    You know what they say about those who shout the loudest...:D

    Their S/N ratio is the highest?
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  8. Looking back at the modern wingsuit history (1998 - 2018), this is how I see it. Of course, this is just my opinion, and I clearly understand that I might be wrong.

    In bird's eye view, the only thing that happened in this 20-year stretch was the gradual increase of surface area, which pretty much reached the plato in 2008-9 and has been virtually constant for the past decade. (Of course, out of every wingsuit manufacturer's (WSM) product line, I'm talking about the biggest suit.)

    As an automatic result of the surface increase, L/D increased from about 1.5 in 1998 to about 3.0 that was reached somewhere 2010-ish and remained pretty much platoed for several years now. This increase was not a result of aerodynamic ingenuity, it was the result of tailors using more fabric to sew bigger body envelopes. As I explained many, many times, the bigger the suit, the more it "dilutes" the "dirty" aerodynamics of the body, the end result being better. It's like taking a glass of nasty swamp water and making it taste better just by adding clean water to it - the more you add, the less nasty it tastes.

    No rigor scientific methods, no precision instrumentation has been used in 20 years; only the same lame tool, GPS, that, besides some exceptions of windless BASE jumps, is nothing but garbage data pump (useful for those "wind-shopping" bogus world records, though).

    Some opportunities to use research windtunnels have been wasted to produce just pretty PR pictures and marketing.

    Wingsuit "innovation" became this ever intensifying fest of Godzilla Marketing (GM), with product descriptions written by professional marketers, sounding so amazing that one can almost think that the new suit is over 9000 times better than the outdated, last year's model. Yet, no evidence of the major changes, no technical drawings showing the difference A/B and why and by how much it improves the performance, are presented. Just marketing speak.

    By releasing new models often and pushing them hard and making them lasting much less (many suits now have no reinforcement tapes and use flimsy materials that should never be used in parachuting equipment), customers are pushed into fast upgrade cycles, enticing them to part with more money, more often.

    Suit prices doubled, to nearly $2000 of modern big suits. While it's just some more fabric and some more rib stitching, typically done by low-paid workers in sweatshops in Asia, and even in Europe and the USA. The $1000 increase in price is disproportional to increase in amount of stitching and raw materials.

    WSMs now excel at painting zippers, using printed fabric that makes wingsuits look like comforters from bedding section at Walmart, sewing more pockets, and calling it "innovation".

    Major WSMs now have literally battalions of factory pilots, "friends", and dealers, who get suits for free or at deep discount. Many of them also lead this lifestyle of having fun and being paid for it, traveling to exotic places, all paid - travel, lodging, food, lift tickets, helicopters, etc. etc. Who pays for all this? WE DO. A large chunk of that $2000 out of your pocket goes to someone to have fun at your expense. Is this all necessary? Of course, some number of test pilots is always necessary. But for aggressive GM, a *lot* of pilots is necessary. To make all those pretty videos that convince you: "buy... buy... OBEY".

    The thousands of professionally-made new videos of various stunts, extreme proximity flying, aerial maneuvers, freeflying, mattresses of different colors and patterns - all can make a weak mind think that, "look, there's a lot of innovation in wingsuits! stuff like this was not possible in the past!" What the weak minds fail to understand is that pro pilots these days have many thousands of WS (and even WS BASE) jumps, the skill level increased exponentially, being driven not only by mere time, but by GM, sponsoring opportunities, and self-promotion. A lot of stuff that seems to be new, is also possible in older, smaller suits. And some of the stuff, like clean, tight corkscrew, became possible due to higher L/D and lower wingloading, both of which are automatic benefits of simply sewing bigger suits. Same with flare - it's mostly auto-consequence of increased L/D, again, due to bigger suits "diluting" poor body aerodynamics.

    This is the "state of the union" in wingsuiting today. We haven't actually achieved that much in 20 years. Wingsuits could be much much different today than they are, and we'd already have some amazing instrumentation tools, with HUD and all.

    So let's stop being the Stooges that we've been all these 20 years.

    Let's MWGA - Make Wingsuiting Great Again! ((tm) Yuri "Trump" Base :P)

    Wake up, everybody!!!

    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  9. yuri_base


    This video also demonstrates some major benefits of a vane as a WS instrumentation tool:

    1. Vane is already stable pointing into relative wind after less than 2 seconds from BASE exit (let alone skydiving exit):

    [inline Vane1.jpg]

    (iphone 5 screen is shit in direct sunlight)

    It starts measuring L/D right away (~1.5), and it's non-zero from the start, while GR is nearly zero.

    2. 15 seconds - L/D is at about max L/D for this flight (2.7), but GR is only 1.7, but growing:

    [inline Vane2.jpg]

    3. 23 seconds: L/D and GR become equal, 2.7.

    [inline Vane3.jpg]

    4. 42 seconds: using milking of speed to convert it into GR (~3.5, the scale is highly nonlinear after 3.0 there) that is higher than L/D:

    [inline Vane4.jpg]

    My flight was very poor, I was simply tired of previous 20-30 jumps in a row (I'm not fit, get tired very quickly). That's why my flight didn't have that GR peak, my transition from exit to full flight was mushy, not at constant, max L/D. Also, at about time for my wingloading to have the GR peak (20-25 seconds), it's about time to make a turn which dampens GR.

    WSE in all their glory. WSE make true flight analysis and instrumentation possible. Let the mass christening of wingsuit community into the new age of wingsuiting begin today! Halle-fucking-lujah! Stop CoWing, start thinking fresh out of the box! I have high hopes that I'm not alone in trying to nudge the WS industry from the stagnation swamp it's been sitting at for the past 12 or so years.

    Let the Great Wingsuit Revolution of 2018 begin!

    Let's "Make wingsuiting great again!" (tm) ;)

    Yuri
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

    Vane1.jpg

    Vane2.jpg

    Vane3.jpg

    Vane4.jpg


  10. // https://youtu.be/ee-vE1S-v8s

    As anyone can see, I'm a very poor mechanical engineer - the vane jitters sideways, which introduces significant acceleration noise from vibrations, I already wrote about these challenges in data filtering.

    Maybe, a good mechanical engineer will come up with a better vane mount (3D printed even?) that eliminates these parasite vibrations? And become that Solar System-famous (and possibly, Universe-famous) WSV #2?

    Maybe, a good aerospace engineer will come up with a better vane itself (3D printed even?) that is slick and more aerodynamic (less vibrations from turbulence, too!)? And a belly arm that creates less parasite drag than that trekking pole? And become that Solar System-famous (and possibly, Universe-famous) WSV #3?

    (that drag from the pole is surprisingly noticeable: without the pole, at Walenstadt, in V4 and exit weight ~250-260lbs, I could fly all the way though the Crack and open at comfortable 40s canopy ride altitude above the PG landing near the soccer field; with the pole, I could not reach that far).

    Where art thou, good aerospace and mechanical engineers? Chewing in the swamp of WS industry stagnation like CoW?
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  11. aonsquared

    Ever heard of proof by contradiction?



    Why use ancient methods, I've invented a new method that works with 100% success: proof by exhaustion. I carpet-bomb with formulas until naysayers drop dead from exhaustion. Also, I let those who repeatedly ask silly/trolly/useless/uneducated/answered in OP questions, exhaust themselves by responding with deafening silence.

    It works - one is already not saying that WSE are wrong and thus is now WSE #4. Who's gonna to be WSE #5?
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  12. By the way, the 2nd video (from my helmet cam) clearly demonstrates that I made a too aggressive turn and it was uncoordinated, there was a strong slip component, as can be seen by the pole being pushed sideways by the relative wind. Maybe, it's a good idea to attach a wool thread near the end of the pole to see the slip angle and practice better coordinated turns.

    [inline UncoordinatedTurn.jpg]

    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

    UncoordinatedTurn.jpg


  13. I wonder when (or whether if at all) somebody else will make a vane for their smartphone or smartwatch (or even a Pitot tube) - the magic instrumentation tool for wingsuiting, that has these magic properties of totally eliminating wind influence (as it points into the relative wind) and apparent gravity components being directly related to L/D, Kl, Kd? Who's gonna be the amazing WSV #2? (WSV for "wingsuit vane")

    I've been waiting for this for years, and it's total *crickets* worldwide (even Solar System-wide, and possibly even Universe-wide). It's not a rocket science, just measure your device and use simple materials, like thin aluminum, acrylic, etc. and a telescopic trekking pole and an aluminum belly platform. If *I* can do it (I must admit, my hands grow from my ass, I'm very poor at making physical things), *YOU* can do it, too! Just several hours of basic DIY stuff. And you get the most advanced and revolutionary wingsuit instrument in the world! (and no, I'm not trying to sell L/D Magic app (iphone only) - it's too complicated for most users, you need to understand things like Kalman filter and properly configure parameters for it, and exit at precise count "C-ya!"; I have a much simpler, FREE app, L/D Vario, that runs on virtually any smartdevice and provides real time visual and audio feedback for L/D, not this garbage thing called "ground glide ratio" that comes from GPS, fuck that!)

    You can see the logistics of using a vane on a BASE jump in these videos of my jump with James about 5 years ago:

    https://youtu.be/7pTzCAl2UtA

    https://youtu.be/nNHuB7XFTBQ

    https://youtu.be/ee-vE1S-v8s

    Any questions are welcome.

    WSV #2, I'm waiting for ya, you'll be my hero!!!


    In the other news, I'm proud to announce the hard-earned WSE #4: Leeeeeeeeeeeeeroy Jenkins! :D

    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  14. LeeroyJenkins

    Yuri, you honestly don't see whats wrong with you GR v. Time graph with the various L/D plots on it?



    No.

    LeeroyJenkins

    After all you have said about L/D and GR being different you don't find it weird that the steady state GR=L/D?



    No.

    LeeroyJenkins

    You don't think it's weird that your equation overshoot steady state?



    No.
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  15. LeeroyJenkins

    Overshoot is what your equations are doing. Look up Gibbs phenomenon if you want the fancy math version.



    https://en.wikipedia.org/wiki/Gibbs_phenomenon#Explanation

    Wikipedia

    Explanation

    Informally, the Gibbs phenomenon reflects the difficulty inherent in approximating a discontinuous function by a finite series of continuous sine and cosine waves.



    Has absolutely nothing to do with WSE. A better analogy would be a pendulum in viscous liquid where it will swing and overshoot the equilibrium state due to initial energy. And the less viscosity, the more it will overshoot (like the higher L/D, the higher peak GR will be achieved; with L/D = 3.567, the peak will be equal to infinity).

    Just like that cycloid example mentioned above. Totally irrelevant.


    LeeroyJenkins

    I made a statement off the fact that your spreadsheet said after 30 seconds there would be a GR of ~4.5



    After 18 seconds, not 30. And what is wrong with that? I personally have experienced this "overshooting" on all BASE jumps when starting to fly quickly (i.e. using mushy, high-lift flight mode with AoA ~ 45 degrees) was not necessary and I could dive at constant L/D. The time of onset of this planeout and its duration depend on wingloading - shorter for light jumpers and longer for heavier ones. It's all in the same post as with the Excel solver.

    [inline PlaneoutTheoryVsExperiment.gif]

    [inline PlaneoutVsLD.gif]

    [inline PlaneoutVsWingloadingAndLD.gif]
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

    PlaneoutTheoryVsExperiment.gif

    PlaneoutVsLD.gif

    PlaneoutVsWingloadingAndLD.gif


  16. I will continue, because there's never enough times to hammer the differences between L/D and GR.

    Imagine you're standing on a sand surf board on a sand dune. (Suppose) the board has a coefficient of friction 0.4 with sand. (This means that if total weight of person+board is 100kg, and it's on level sand surface, it will take 40kg of force to move it horizontally at constant speed.) If you stand on a slope with the angle arctan(0.4)=21.8 degrees to horizon, the board will juuust start sliding on sand, because at this angle the component of weight parallel to slope becomes equal to friction force. But if you make a half-pipe from steel to first fall straight down, gain a lot of speed, and then start surfing the sand, then you for some time can slide on a more shallow slope, like angled at only arctan(1/4.6)=12.3 degrees. Of course, you will start slowing down and you can't sustain sliding on 12.3 degrees indefinitely, only on 21.8 degrees you can slide indefinitely! Also, given enough gained speed, you can even temporarily go up on the upward sand slope!

    As I explained in some previous posts, L/D is analogous to the inverse of the coefficient of friction, so in this example L/D = 1/0.4 = 2.5 and sustained glide slope is 21.8 degrees to horizon. The "glide ratio" in this case is simply the inverse of the tangent of the slope to horizon. So, it was zero on the top of the half-pipe (sliding on steel straight down), then the pipe increased it, and you peaked "GR" at 4.6 (you overshot "L/D" of 2.5!), but it decreases after that and you can only sustain, of course, 2.5 in the long run. But if you have enough gained energy from a "dive", you can even temporarily go up - "flare".

    Note that at all times the coefficient of friction remained 0.4 (L/D remained 2.5), while "GR" increased from 0, peaked at 4.6, and then fell to 2.5 in the long run.

    Have I hammered the diff between GR and L/D, L/D and GR, hard enough? Or it's still not enough?
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  17. LeeroyJenkins

    Here is Yuri's WSE spreadsheet for a theoretical base jump.

    Now its been awhile since I took control theory but what's with all that overshoot in your graph?

    I'd take a 4.6 Glide any day.



    Over and over again - a clear demonstration of lack of understanding of difference between GR and L/D. And I'm tired to explain it over and over again, but I do it for other readers who will finally get it.

    GR is simply the ratio of current horizontal [air or ground] speed to vertical [air or ground] speed. (thus, different GRs - ground GR, measured by GPS, and air GR, which is equal to ground GR only when there's absolutely no wind and thermals/downdrafts) It can take any value from 0 (first fraction of a second in BASE exit with no forward push) to positive infinity (when pilot transitions from full flight into a flare and flies a concave arc trajectory, and the speed is purely horizontal for a moment) and then flips through negative infinity to some negative number corresponding to steepest climb angle during the flare.

    L/D is NOT a ratio of speeds, L/D is literally a lift-to-drag ratio, at any moment in time, and in general is not equal to GR. For example, 1-2s after BASE exit, GR is essentially zero (jumper is mostly just falling down), but L/D is equal to that of the flight mode he's currently in; for example, if pilot managed to "nail" the AoA and body position after 2 seconds, to that of his best L/D (say, 3.0), then L/D is 3.0 at that moment! So, GR~0, while L/D=3 at that moment.

    L/D has hard top boundary (the bottom is, of course, 0 - no lift, pure drag) that is determined by aerodynamic "finesse" of the gliding apparatus, in our case, wingsuit and its pilot. And at current state of the art of wingsuiting, max L/D across all pilots, rich and poor, of any skin color, big ego or small - is approx. 3.0, give or take maybe +/-0.1, for an average body build and average bulk rig. (of course, superlean pilots - possibly just released from Guantanamo Bay - with superthin rigs have a slight advantage over the average builds, probably by 0.1-0.2)

    Is this explanation of the difference between GR and L/D enough?
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  18. LeeroyJenkins

    The most obvious is the overshoot in the graphs for GR.



    What's an "overshoot"? Like, the graph line going out of axis boundary? Just set the automatic min/max axis values.

    LeeroyJenkins

    The second thing is the 4.5 mag glide that peaks.



    And? What's wrong? That's what glide does on a WS BASE jump, it peaks, provided the pilot flies with consistent AoA in flight mode that has at least L/D of approx. 1.0 (as demonstrated in this picture; below L/D=1.0, GR doesn't reach a peak higher than L/D, it just increases monotonically from 0 to L/D).
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  19. LeeroyJenkins

    If you put in values that are well within the range of wingsuit performance you should get valid results back. I put Vx=100 and Vy=40 in the attached spreadsheet. Both numbers that are very reasonable to travel through air.



    Correct. Putting in Vxs=100mph and Vys=40mph with initial speeds Vx=0 and Vy=0 would correctly model a WS BASE jump with realistic flight mode (for someone, in some wingsuit with L/D=2.5), provided the flight mode remains constant throughout the flight (i.e. the pilot holds the same AoA and body configuration all the time). Why the results seem to be invalid?
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  20. LeeroyJenkins

    you posted a link to a spreadsheet where you enter Vx and Vy. It doesn't mater if they are gps or from a vain, as long as they are within a reasonable % of wingsuit ability your equations should produce reasonable results.



    Excel solver from this post?

    http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2563142#2563142

    It uses initial airspeeds Vx and Vy, as well as a constant flight mode [Vxs, Vys] and then solves WSE for a given length of time (again, relative to air). Not ground Vx and Vy that are from skydive's GPS data. If one uses the latter, of course they would get complete nonsense! Also, one needs to know the flight mode, or try to guess it by trying the fit the theoretical trajectory (or at least, speed profile) to real one; if one just uses default numbers pre-entered in the spreadsheet, they would again get complete nonsense.

    I thought this was obvious.

    Also, I recommend using Wingsuit Studio instead, since it uses proper altitude density correction, as well as more robust Runge-Kutta (4th order) algorithm to solve WSE (instead of Euler in the simple solver above).

    Again, a perfect example of using [this time] a right tool, but for the wrong job. Like using an oscilloscope as a hammer.
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  21. LeeroyJenkins

    Attached is my first flight in a freak 2. Also attached is the Raw data. It wasn't the longest flight as I pulled high. It also wasn't a fast flight.



    and

    LeeroyJenkins

    I’ve played with the WS equations and used my GPS data in them and gotten absolute nonsense as an output.



    This clearly demonstrates total lack of understanding the basic premise of WSE: they only consider motion relative to air, in the inertial reference frame of the airmass (which is assumed to be moving at constant velocity, or be completely still). In WSE, Vx, Vy, ax, ay are speeds and accelerations relative to air, not the ground!

    If one uses GPS data from a skydive, with unknown wind, it's patently ridiculous to "used my GPS data in them and gotten absolute nonsense as an output". It's like recording a GPS track of walking to a restroom in a jet liner and giving it to a running coach asking, "how's my running? looks promising, eh?"

    Again, it's like taking the problem of determining the strategy for fastest time from A to B in wingsuit, and applying solution for a completely unrelated problem (bead sliding on frictionless string).

    The GPS data from skydives should be considered complete garbage, as the wind can never be reliably subtracted.

    The only value of GPS is for windless BASE jumps. Then it's in reasonable agreement with WSE (taking into account inaccuracy of GPS), as platypii's, Hartman Rector's, and multiple mine examples demonstrate.

    Use the right tool for the right job.
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  22. This is the most impressive and zeroest S/N ratio body of work I've seen in my life. (see quotes below) Asking - dozens of times! - questions that are answered in the OP and links therein. Anyone even read original posts anymore, anywhere these days? Or just jump to the latest reply and make a knee-jerk reaction to that? Complete with unnecessary personification and personal attacks while what we discuss is just equations, numbers, software, instrumentation, articles, and stagnation of innovation in WS industry?

    In the recent years I've come up with a radical change in how I post anything in the forums: I never use the word "you" (other than a depersonalized "you", like "If you know of anything not listed, please share."), I never personificate my replies, I only direct them to the subject at hand. (The "C" thing was the only exeption caused by sudden discovery of the situation. I'm done with this.) First of all, it keeps conversations civil. Second, if you don't know the person in real life, it's just a username to you, and it could be even artificial intelligence! (it would be totally stupid to become red-face angry at... a bot!) Now, read all the replies from my opponents and count all "Yuri"s and "you"s and "he"s in them!

    Anyway, I hope more folks here and everywhere adopt this approach and we see a lot of interesting things here to read and discuss. This forum in particular has a long history of being a swamp (2010-2018) with nothing interesting in it, let's "Make it great again!" LOL

    LeeroyJenkins


    You are so full of shit, explaining why would be like talking to a brick wall.



    LeeroyJenkins


    Literally not how science works, the burden of proof is on you.



    LeeroyJenkins


    he is laughable on this topic.



    aonsquared


    And he's just blaming most of the skydiving community for not accepting his genius. What I find laughable is his excuses for not providing proof.



    LeeroyJenkins


    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.



    LeeroyJenkins


    Did you just use your own equations to prove your equations right?



    LeeroyJenkins


    “I am very smart👌🏻, so much smarter that’s you🖐🏻, probably the smartest 👌🏻 person ever☝🏻.” - yuri



    LeeroyJenkins


    In simpler words. Yes he used his own equations to prove that his equations are right.



    LeeroyJenkins


    Yuri, why don’t you post your equation derivations? Or provide them somehow.



    LeeroyJenkins


    yuri, where are those derivations I asked for? Why won’t you say what you believe the magic L/D number translates to for wingsuit flight?



    LeeroyJenkins


    Can you just post your derivations? No more nonsense.

    Can you also explain why you think 3.567 is the magic L/D number and what that number translates to in wingsuit performance?



    LeeroyJenkins


    Are you incapable of answering simple questions?

    What does your magical L/D number translate to for wingsuit performance?

    Where is the mathematical derivation of your equations?

    Where is the physical data to back up your mathematical derivation?



    LeeroyJenkins


    Still waiting Yuri.....



    Skwrl


    There's definitely a CoW in this thread, and he's the one avoiding questions. I'm back to my comment about unsubstantiated mathsturbation. Seems like the models aren't substantiated - at least based on the reviews so far. I guess the world still isn't ready for the Yuri Device (remember when it was called that?)



    LeeroyJenkins


    Nice Dodge, answer these.

    What does your magical L/D number translate to for wingsuit performance?

    Where is the mathematical derivation of your equations?

    Where is the physical data to back up your mathematical derivation?


    Can someone repost these questions? I don't know if he is just ignoring me or he blocked me so he doesn't even see my comments.



    LeeroyJenkins


    As for now Yuris crack pot equations are unproven pshdoacience.



    aonsquared


    Again, I'm not really seeing anything new or revolutionary?



    LeeroyJenkins


    Im pretty sure this is how he came up with his equations. They prove what he wants them to and nothing more.



    aonsquared


    According to your earlier posts, do your wingsuit equations assume that either:

    a) L points perpendicular to the trajectory curve? Or
    b) L always points "up" opposite the gravity vector? Or
    c) perpendicular to the wingsuiter?

    Just trying to establish your conventions.



    LeeroyJenkins


    Whats your wing loading when you include the weight of your ego?


    But really, if wingsuit manufactures posted the same nonsense you did, people like aonsquared and I would still criticize them. One thing I do know however, the aerospace engineers that work to design these suits understand aerodynamics way more than you do. You can't even answer simple questions because you know the answer will undo your theories.



    LeeroyJenkins


    Hey Yuri,

    What's your highest performance wingsuit flight. Starting to get the feeling you aren't very good and want to blame the suit instead of the pilot. Your ego is so big you invented equations to make yourself feel better because all those MWS are keeping you down.



    LeeroyJenkins


    Dude,

    What does this have to do with you coming up with some revolutionary wingsuit equations? It's hard to keep track of the point of this thread with you posting all sorts of nonsense. You fail yet again to answer simple questions?

    What is you fastest wingsuit flight?



    LeeroyJenkins


    Dude, are you ok.... like mentally?



    BryanCampau


    This is a sad attempt at getting the attention off of yourself, Yuri.

    You are still ignoring the questions directed at you that are relevant to this thread.



    LeeroyJenkins


    Yuri, you have to prove the WSE are correct. The burden of proof is on you.

    I have asked you multiple times what the significance of your "Magic" L/D numbers are and you continue to fail to answer.



    LeeroyJenkins


    Yuri, came up with the WS equations. The burden is on him to provide the evidence to prove that the equations are mathematically correct and accurately represent the physical aspects he claims they do.



    The full copy of the thread can be found here and in earlier captures:

    https://web.archive.org/web/20180927232919/http://www.dropzone.com/cgi-bin/forum/gforum.cgi?do=post_view_flat;post=4896302;page=1;mh=-1;;sb=post_latest_reply;so=ASC
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  23. let's move on to Wingsuit Equations, shall we?

    Anyone succeeded in debunking WSE? I see that the initial denial stance of "they are 100% wrong!" changed to "I don't see any significance in them". Does this mean WSE are now accepted even by the stoogiest of the naysayers? We need to be clear on this to proceed.
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

  24. For wingsuit (and even tracking), exposing slider works really well to eliminate canopy cocoon hesitations and resulting from them offheadings, linetwists, and hard openings.

    [inline Cocoon.jpg]

    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio

    Cocoon.jpg


  25. I hope Jarno will not only show decency by coming out and saying in the Incidents forum that it was him, but send some of his windtunnel money to Vasily's mother. (https://vk.com/mvkarp) Even if they keep the tunnel shut down for 6.5 hours instead of making this stupid "world record", the saved electricity money would probably pay for a day of Vasily's recovery.
    Android+Wear/iOS/Windows apps:
    L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
    iOS only: L/D Magic
    Windows only: WS Studio