• Content

  • Joined

  • Last visited

  • Feedback


Community Reputation

0 Neutral

Jump Profile

  • Years in Sport
  • First Choice Discipline
    Wing Suit Flying
  • Second Choice Discipline
    BASE Jumping

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. yuri_base

    Wingsuit research

    Everyone is most welcome to compile their work in a post here. Your thoughtful posts here on dz.com, bj.com, or elsewhere, articles you wrote, calculations you've done - share the love, don't be shy! It will be a very interesting read. Everyone remembers what they've done over the years; but not what others had done. It's like a ton of needles thrown from a plane onto a field of haystacks. Who can find them all?! Collect all your needles from your haystack and give it to us! If you have any critical thought on any material in this thread, go ahead, shred it! True science does not know "politics", little talk, tact, pretty lies... True science is the pure truth, it's fucking straightforward!
  2. yuri_base

    Rafale vs. Freak2 ?

    This is the extent of innovation in WS industry. Change materials, colors, patterns, zippers; make more pockets. The suit itself is pretty much the "same old same old".
  3. yuri_base

    Wingsuit research

    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.
  4. yuri_base

    Wingsuit research

    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. [inline Vane.jpg] 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): [inline Cow.gif] 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: [inline DoneWithWingsuitScience.jpg] 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. [inline Brento.png] [inline Sputnik.png] 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.
  5. yuri_base

    Wingsuit research

    YB12 - The Great Confusion: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3112987 I just started to read #8, the big dissertation (1000 pages!), The Effect of Surface Materials and Morphology on Wingsuit Aerodynamics. And immediately was SHOCKED to find that it falls into the same fallacy as Geo did - applying the math for powered level flight to wingsuit flight! I pointed about this confusion many times in wingsuit forum. Hopeless. In 2009, Geo wrote this post: http://www.basejumper.com/cgi-bin/forum/gforum.cgi?post=2911547#2911547 which clearly showed his wrong approach, and a couple of posts below, I explained it to him. Hopeless. He continued doing it the wrong way. Then, he posted about his study on effects of altitude on start arc: http://www.basejumper.com/cgi-bin/forum/gforum.cgi?post=2923164;#2923164 - apparently, this was part of his preparation for that fatal jump. And it's quite possible, that this Great Confusion cost him life, if there was an error in his calculations ([url http://www.blincmagazine.com/forum/wiki_index.php?title=BASE_Fatality_List]BFL[/url] #146). Cf. pages 47-49 in the Sestak's dissertation. As Geo, he separates total drag into two parts: induced drag and parasite drag. As I explained in "The Great Confusion" post and in reply to Geo, this is an artificial math trick designed to make life a bit easier when doing calculations related to powered level flight, but they are useless and even harmful, when applied to non-powered gliding flight! [inline Fallacy.png] Wingsuit's drag does not go to infinity as the speed approaches zero, otherwise, we'll be like a fly that flew into honey, after a BASE exit, since the enormous drag will stop us right away! Drag is always (with high Reynolds number) proportional to the square of airspeed! Unfortunately, the way they teach aerodynamics to aeronautical students, pounds this fallacy into their brain. From my observations over the years, aeronautical students and engineers do not have a solid grasp of fundamental physics concepts to recognize this fallacy. They fall into this pothole every. single. time. Finally, both Sestak's and Robson's work fail to mention the prior art - Wingsuit Equations (ca. 2006) and L/D Meter principle (i.e., the possibility of precise measurements of wingsuit flight characteristics) - in their work. (Robson learned about WSE and Wingsuit Studio in 2009.) Wingsuit Equations are like Newton's F=ma in wingsuit dynamics. For an aeronautics researcher who is also a wingsuit pilot, to not know about them in 2017 is laughable, they are easily googled by "wingsuit dynamics", etc. It's like writing a doctoral dissertation on mechanics and not knowing F=ma. Or like a Ph.D. candidate in electrical engineering doesn't know Ohm's Law. You can run, but you can't hide from the Wingsuit Equations!
  6. yuri_base

    Wingsuit research

    Correction to #7: http://web.mst.edu/~spaceg/2017_annual_meeting/2017%20Reports/2017_MOSGC_Ferguson.pdf
  7. yuri_base

    Speed skydiving - head down

    // I'd like to see you try ;) I like to sit on a couch and give other people crazy ideas to try. To induce a spin, very little input should be necessary, just a twist in the upper body, perhaps? So, no sticking out extra control surfaces, just a twist. As far as the how fast, the main idea was actually not stabilization from gyroscopic effect, but to see if coefficient of drag can be reduced by twisting the dirty airflow behind. Usually, the research of flying bodies in windtunnels is done on static objects; I don't remember reading anything about rotating (esp. non-symmetrical) objects and the effect on Cd. Could be something surprising...
  8. yuri_base

    Wingsuit research

    Here are some resources about wingsuit research in the last 12 years or so for those interested. If you know of anything not listed, please share. Let's keep this up-to-date as a central "What's new in wingsuit research?" reference. 1. Geo Robson: http://www.idsc.ethz.ch/research-dandrea/research-projects/archive/actuated-wingsuits.html 2. Israel Institute of Technology: https://aerospace.technion.ac.il/projects/aerodynamic-design-of-a-wingsuit/ (can't find the paper though, probably, was sent to me by email and is lost now) 3. Karl Nyberg: https://mdx2.plm.automation.siemens.com/sites/default/files/thesis/pdf/Examensarbete_Karl_Nyberg.pdf 4. Icarus Project: http://generic.wordpress.soton.ac.uk/icarus/ (no papers) 5. Hartman Rector: The Excel spreadsheet (3D Wingsuit Equations solver) was sent in an email to me, don't know if he wants to publish it or not. A simple 2D Wingsuit Equations Excel solver can be found here: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2563142#2563142 3D WSE in fixed frame of reference can be found above "FUCK YEAH!!!" in my notebook here: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4825693#4825693 6. MIT: https://www.researchgate.net/publication/245481528_Wind_Tunnel_Testing_of_a_Novel_Wingsuit_Design 7. Maria Ferguson: https://openscholarship.wustl.edu/cgi/viewcontent.cgi?article=1000&context=engr310 8. Timothy Sestak: https://commons.erau.edu/edt/355/ I'll throw in some of my stuff as well: YB1 - "Superterminal" wingsuit idea: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2084537#2084537 YB2 - Wingsuit Equations, 2D: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2563135#2563135 3D: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?do=post_attachment;postatt_id=148684; YB3 - Accelerometer on a vane as L/D meter principle: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2563139#2563139 YB4 - "magic" L/D's - 1st, for maximum horizontal speed: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2253168#2253168 - 2nd, for level planeout after headdown dive: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3148124;#3148124 - 3rd, for level planeout after BASE exit: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3145335;#3145335 YB5 - wingsuit hysteresis: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2532192 YB6 - Wingsuit Studio, WSE-2D solver, L/D Calculator, World BASE Race simulator: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3626009 (download at http://www.pureflyingmagic.com) YB7 - flying with just a leg wing and like Superman: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2264543#2264543 (additional experiments with top above waistline removed for Phantom-1 and Vampire-2, circa 2012-ish and with arm wings cutoff completely on Vampire-4 and flying like a Superman, with arm(s) stretched forward, circa 2015-ish) YB8 - Z-Device, with accelerometer and Pitot Tube on a vane: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3069522#3069522 YB9 - Analog L/D Meter (laser-cut bubble level with mathematically calculated curve): http://www.dropzone.com/cgi-bin/forum/gforum.cgi?do=post_attachment;postatt_id=120198; http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3796788#3796788 YB10 - Smartdevices on a vane as real time wingsuit instrumentation: Links to the apps (L/D Vario and L/D Magic) can be found at http://www.pureflyingmagic.com Examples of flights with smartphones or smartwatches on a vane can be found here: https://www.youtube.com/channel/UCFaKavzIFhlKuFp40l4osIQ https://vimeo.com/pureflyingmagic Some examples of data and discussion of challenges: http://www.basejumper.com/cgi-bin/forum/gforum.cgi?post=2982476 YB11 - Fast, Accelerated Proximity principle: http://www.basejumper.com/cgi-bin/forum/gforum.cgi?post=2991086;#2991086 (for Wingsuit FAP app links, see http://www.pureflyingmagic.com)
  9. yuri_base

    Rafale vs. Freak2 ?

    (moved to a [url http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4896302#4896302]new thread[/url])
  10. yuri_base

    Rafale vs. Freak2 ?

    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.
  11. yuri_base

    The WingNut...an Airspeed Indicator for wingsuit pilots

    Good work, John! I have only one point to make: unfortunately, there's just no way to accurately measure airspeed without putting the Pitot tube on a vane a good distance from the body (0.5m is, from my experiments, an absolute bare minimum). It won't give undisturbed speed if mounted on a gripper only inches from the arm. Unfortunately, it's not possible with wingsuits to mount Pitot tube close to "fuselage" or wing and calibrate it to account for airflow slowdown and deflection, like they do on airplanes. Vane on a long stick is the only way for us. Here's an example of a vane on a helmet: [inline LD_Meter.jpg] and on the belly: https://vimeo.com/132279770 0.5m. Minimum. Sorry. Physics sometimes is such a bitch. Godspeed! Yuri
  12. yuri_base

    Speed skydiving - head down

    What if you do a fast continuous corksrew, like a bullet? I wonder if it not only will improve stability, but reduce drag coefficient as well as the airflow behind you will be more "organized" in a tight spiral, vs. random burble swirls.
  13. I guess "Reverse Engineering" was a poor choice of words. I meant to say, disassemble and make a replica for your own use. Reverse engineering usually means making a new product based on someone else's design and selling it en masse. That is, indeed, stealing someone's hard work. You bought a book. The book is old now and falling apart. You want to continue reading it, you make a xerox copy and bind the pages. For your own use. That's not stealing. 100% legal and 100% ethic. (I don't think any author would or can object to what you're doing with what you paid for, in your privacy, as long as you don't distribute it.) And no, I'm not neither planning on starting such a business nor making this replica myself. I was wondering if there is and why there isn't such a business already, of which I'd be one happy customer.
  14. I've never bought a squirrel before. I'm actually camping right now and there's a couple of very chatty squirrels in the trees near me. They were probably trying to sell themselves to me. Buy us! We're much better than the last years'! Can I get just the top of X-2? I cut my V-2 in half and left only the leg wing, making a rocket-fast leg wing pants. If I join them with the top of X-2, I will have a new Frankenstein suit - VX-2. It will fly at true L/D=7.0 measured with my instrument. Or I can sell my V-2 rocket pantz for only $2K (only $10/mph, much cheaper than slow mattresses) so I can buy one of those squirrels.
  15. I'm not a rigger and the most complex thing I can do with my hands is to pick my nose. So maybe my question would sound stupid to a pro, but so be it: A customer brings their suit and all necessary materials. The rigger closely examines the suit and based on their prior experience (this won't be their first wingsuit done!) carefully unstitches it. Suppose it takes the full 8hr workday. On the second day, he puts the parts on top of fabric roll and makes outlines of them with a marker and cuts them with scissors (the old fashioned way, no expensive laser cutter, no computer necessary!) The whole day - just outlining and cutting. On the 3rd day, he puts together the main "envelope" pieces. On the 4th day, he puts all the ribs inside. On the 5th day, he sews in the zippers, inlets, grippers, pockets and other small parts. All this assuming this is not his first suit, he already figured out the general flow. The suit replica is ready. For 5 days of work, he receives $1000 cash (and no material costs). Then he has a normal weekend. Next week, another customer, another suit, another $1000. Weekend. Rinse, repeat. That's more than $4000 a month. Clean, hard cash. Is this unrealistic? One full day for each step? Full workweek to copy a suit. $1000/week. No one would be interested? Maybe, riggers make $400,000 a month pencil-packing and $4K is a pocket change?