yuri_base

brokenback

There is the Garmin Varia Vision but I think if has to be linked to one of their devices.

Something like this, but non-proprietary and cheap ($100 tops).

I hope Apple will come up with some AR HUD companion for iphone; once Apple starts doing something, many follow and prices drop.

aonsquared

Quote

The solution of these is:

Kl = Vxs/Vs^3
Kd = Vys/Vs^3

With these adjusted coefficients, the wingsuit equations are

dVx/dt = g*V*(Kl*Vy - Kd*Vx)
dVy/dt = g*(1 - V*(Kl*Vx + Kd*Vy))

Now the unknown wingsuit parameters (wingloading mg/S and aerodynamic properties Cl, Cd) are "hidden" inside coefficients Kl and Kd, which can be easily calculated from sustained horizontal and vertical speeds.

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?

The equation for D is "the whole pie", as I explained in my reply to Geo. Splitting the drag "pie" into two parts, while can be done, is totally unnecessary for wingsuits. We still have to eat the whole pie. Split is useful for powered aircraft flying level at constant speed. Does not apply to us.

aonsquared

Also, you said in the post:

Quote

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.

Because,

Quote

With these adjusted coefficients, the wingsuit equations are

dVx/dt = g*V*(Kl*Vy - Kd*Vx)
dVy/dt = g*(1 - V*(Kl*Vx + Kd*Vy))

Now the unknown wingsuit parameters (wingloading mg/S and aerodynamic properties Cl, Cd) are "hidden" inside coefficients Kl and Kd, which can be easily calculated from sustained horizontal and vertical speeds.

aonsquared

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.

Yes, Kl and Kd vary with angle of attack, and they form a polar curve in [Kl, Kd] space. This curve can be obtained from "natural research windtunnel" - your own flights. And can be subsequently used in modeling, for example, answering questions: what sequence of flight modes (Kl, Kd pairs) would be a winning strategy for competition in speed? in distance? in time? etc.

I strongly recommend contacting Hartman, may be he will share his brilliant spreadsheet that uses 3D WSE. (maybe he already posted it somewhere on social media, idk)

aonsquared

The V in this equation also denotes airspeed, and GPS measurements only measure ground speed.

Yes, I only operate with airspeed. GPS measurements cannot be trusted since the wind is never known with sufficient for us accuracy. L/D Vario and L/D Magic with the first two Kalman Filter models (with accelerometer and accelerometer+gyro when iphone is mounted on a vane) are completely independent from wind influence since the vane always point into relative wind, not apparent ground impact point.

TheEdge

******guys pls ...stop with those altimeters wrist/arm band holders...waiting for a Head Up Display (HUD) directly on the helmet visor...

Tx

Anyone know any news/rumors on any compact HUD (like Google Glass, but affordable) coming out in the near future? HUD that just gets data from the phone, not a computer in itself, like Microsoft HoloLens.

i think this will be the natural evolution...

Yeah, all I need to just mirror phone's display in the eye, that's it. HoloLens and similar AR glasses are just too bulky and expensive.

TheEdge

guys pls ...stop with those altimeters wrist/arm band holders...waiting for a Head Up Display (HUD) directly on the helmet visor...

Tx

Anyone know any news/rumors on any compact HUD (like Google Glass, but affordable) coming out in the near future? HUD that just gets data from the phone, not a computer in itself, like Microsoft HoloLens.

Based on this conversation with "altimeter designer at AO(N²)" (per signature), I would not recommend the products from

https://www.aon2.co.uk

since they are "black boxes" (we don't know what they do inside) and as obvious from above, the lack of knowledge of physics and aerodynamics can result in errors in outputs. I wouldn't trust it!

aonsquared

And if you're a PhD then you would also have published a few academic papers - so you're not really 'outside' the system are you?

After my PhD in 2005, I'm not in academia and not doing physics professionally. It remains my hobby as applied to wingsuits and whatever other interesting for me areas I find it useful and fun to apply to.

http://www.pureflyingmagic.com/About/

aonsquared

Quote

(And I strongly think, it never will.)

um...

Other than "um", any rigor proof?

aonsquared

You can't have L isolated on one side of the equation then have it on the other side too. Same with D. Equations need to be equal (that's why they're called equations).

(L/D) on the right side is used as a notation for a number, not as literal lift devided by drag. I can denote it by some letter, e.g. greek gamma. In the absence of rich formatting here, I get around this limitation by enclosing the number L/D in parenthesis: (L/D). For example, if L/D=2.5, just substitute 2.5 wherever there's (L/D).

Same for drag in sustained level flight:

D = L/(L/D).

It's not literal (otherwise, it's like D=D). It's "take the lift (1000kg), devide by L/D of the plane (10), you get drag 1000/10=100kg".

I thought this was pretty obvious.

aonsquared

Well, the burden of proof is really to prove that your "equations" are correct, as you haven't provided any proof that the prevailing academic thought on aerodynamics is wrong.

I proved that they are correct by deriving them using proven physics (I'm Ph.D. in Physics) and aerodynamics laws. The derivation is here:

http://www.pureflyingmagic.com/Content/Knowledge/Resources/Articles/en/WingsuitEquations.pdf

I have no further "burden". If anyone scientifically proves them wrong, not just saying they are wrong, then I will have a burden to confirm my mistake. This hasn't happened yet. (And I strongly think, it never will.)

aonsquared

The burden of proof should be on you as you're using them to instruct other wingsuiters and if they change their behaviour according to your possibly incorrect formulas, you should have the experimental data to back it up.

I've done it many times, both deriving my aerodynamic parameters from my flights, and using this data to model flight. Hartman does this even in 3D!

aonsquared

I don't have time to fully review your experimental methods, but without wind tunnel tests and only relying on wingsuit jumps with variable weather data (you did record all wind conditions, temperatures, pressures, and humidity, right?), with noisy instruments that have not been calibrated against laboratory references, and of course a very variable and very human test model, lack of convergence testing and instrument parameters, lack of error bars in your final graphs - there's a lot to work on.

Yes, there's a lot to work on, but a lot of work is done already. I collected some of my work in OP, the burden to study it is not on me.

Actually, using jumps as a personal research windtunnel is way more superior to lab windtunnels, because 1) it's you, and in your suit tailored for you, not some other guy in a different suit or build; 2) laying on a measurement platform, waiting to get strapped, the blower motors to reach their speed, etc. is tiring, so the test pilot in windtunnel may have a body position not reproducing the real one in flight; when jumping, one has their real body position and can measure true aerodynamic parameters of it; 3) platform itself can introduce errors in measured lift and drag since it is big and interferes with the flow and can't be just subtracted (unlike thin mounting hardware for wing sections).

Re: wind conditions. L/D Magic and L/D Vario on a vane completely exclude wind, since the vane points into relative wind. They measure the motion relative to air, no ground (like GPS).

Altitude pressure is taken into account, of course. Effects of humidity and temperature are relatively minor and are ignored for now (but now that Nixon Mission smartwatch has a humidity and temperature sensors, it can be done).

"a very variable and very human test model" - yes, and it's yourself, which is the best. I'm not fit and very heavy, so, for example, Hartman's data will have little relevance to me. What I need for me is my data.

Instrument noise is taken into account by L/D Magic's Kalman filters.

Calibration is a big issue, need to, for example, put the pole with L/D Magic/Vario on a car in clean airflow and drive on a level road to calibrate 0.0.

There's a lot of work to do, unfortunately, other than me jumping with vanes and Hartman using GPS data, no one has done any meaningful work in deducing the real aerodynamic parameters of wingsuits and applying them to modeling. In 12 years. In the whole Solar System.

That's the state of the wingsuit industry today. 20-year long coma. And continuing indefinitely, it seems.

aonsquared

Quote

L = W*(L/D)/sqrt(1 + (L/D)^2)
D = W/sqrt(1 + (L/D)^2)

Those are not equations. That's like saying 1=2.

These are equations. They allow one to calculate lift and drag, given L/D and weight, for sustained flight. Yes, they are simple Pythagorean cathetuses from right triangle force diagram (W is hypothenuse, L and D are sides). That doesn't make them "not equations".

aonsquared

I'd strongly suggest you publish your wingsuit equations in a reputable academic journal then, it would be good to see full methodology and get it through peer review.

I feel no need. I'm not affiliated with any academic institution, so don't think this is even possible for a person "from the street" to publish articles in academic journals.

For me, it's sufficient to do the way I do it.

For those writing academic articles and even Ph.D. dissertations, it's an academic shame not to mention (either intentionally, or genuinely not knowing it and not simply googling around a little) the prior art that has been developed 12 years ago. Other than Hartman #5, none from the list #1-#8 mention it. It's pure ridiculousness.

aonsquared

So if your force diagram does not balance to zero then your equations are already wrong. Because F = ma.

Which equations? I wrote several above,

Quote

For sustained non-powered flight,

L = W*(L/D)/sqrt(1 + (L/D)^2)
D = W/sqrt(1 + (L/D)^2)

For both sustained or non-sustained, non-powered:

Quote

L = W·Kl·V^2
D = W·Kd·V^2

And then Wingsuit Equations - they are simply F=ma in expanded form for non-powered flight, for any velocity, sustained or changing.

So, which equations are wrong in their respective conditions and where is the math to show it?

aonsquared

Again, I'm sorry for saying it like this. You seem fairly good at maths, but it's really quite unlikely that you've found a groundbreaking new equation.

Yes, I did find groundbreaking equations - Wingsuit Equations, in 2006. I also invented the ways of measuring L/D and other aerodynamic parameters by using accelerometer and other sensors on a vane in undisturbed airflow.

aonsquared

Wingsuiters, as well as any other form of gliding flight, are probably better off using standard aerodynamics equations.

In my opinion, it's quite possible that this is what killed Geo Robson. He used "standard aerodynamics equations" and grossly overestimated his flight path. He didn't "get" WSE (the only person in Solar System other than me who gets them, is Hartman Rector).

It almost seems that aerospace engineers hit a wall when one talks physics and math. They often lack even basics.

A very clear example of this is #8, a 1000-page dissertation for "Ph.D. in Aviation" (!) - not only it has this wrong drag plot and [unnecessary for wingsuits] separation of drag into induced and parasitic, but the whole method of studying effects of fabric roughness on wingsuits is grossly wrong, because taking a high-L/D section of a wing and covering it in fabric and seeing L/D dramatically decrease by half, has little relevance to wingsuits as our L/D is much much lower to begin with, so the effect of rough fabric will be probably within 5%.

aonsquared

I don't think you've explained very well WHY the standard drag polar is not applicable to unpowered flight.

Because wingsuits (and any nonpowered AC) do not have the goal (and means) to maintain the level flight. So we do not change AoA to maintain LF at different speeds; we change our AoA to do, for example, a flare, or to do a fast start in BASE, or adjust it to find some sweet spot, whether it's distance, time, or speed; or to stay in formation; etc. etc. We cannot fly level at constant speed like planes do!

aonsquared

I hate to break this to you but, your equations are wrong.

No, they are correct. Prove mathematically that they are wrong!

aonsquared

You say that drag is proportional to just the square of airspeed ( D~=v^2) but you've probably measured that drag with a constant angle of attack. The reason why the induced drag in the graph increases with decreasing speed is that you need to increase the angle of attack to maintain straight and level flight as you get slower. So yes, this graph is usually meant for powered aircraft in straight and level flight rather than gliding flight.

Exactly. The aircraft has to change its AoA to maintain level flight if it wants to fly slower or faster, so that graph and formulas for induced and parasitic drag reflect that.

A simple numeric illustration. We have a 1000kg plane flying level at 200km/h, with AoA=4 degrees and L/D = 10. We have a simple "cross" force diagram: weight W = 1000kg is down, lift L = 1000kg is up, drag D = L/(L/D) = 100kg back, and thrust T = D = 100kg forward.

Now the plane wants to fly level at 141km/h (200 deviced by sqrt(2)). If it doesn't change AoA, the lift (and drag, too!) will decrease by a factor of 2, since aerodynamic force is proportional to V^2. Now the lift is only 500kg - half the weight, the plane can't fly level! (the drag will be 50kg) We need to increase the lift by 2x. So we increase AoA to 8 degrees, since for thin wings the lift is proportional to AoA in a range of about 0-10 degrees. Now lift is 2x (1000kg), but drag is roughly proportional to the square of AoA (there's an offset to parabola - non-zero drag at zero AoA, but let's ignore it for the purpose of illustration), so the drag now is 50*4 = 200kg! So the airspeed decreased by sqrt(2), but the drag increased by 2x.

This illustrates why for powered aircraft flying level at constant speed, drag increases as the plane tries to fly slower. This is because they have to increase AoA to maintain level flight, which leads to sharply increasing drag.

This is not applicable to non-powered aircraft.

aonsquared

However, in gliding flight you still need to take this graph seriously. Why? Because your lift must still equal your weight! If you are flying your best glide angle, and your lift is not equal to your weight, then your speed will not be constant. You will be accelerating. As you yourself said, F = ma.

No, even for sustained flight, lift is not equal weight, this is because the force diagram is different, there are only 3 forces, and L and D are angled to W (all this is explained in The Great Confusion post).

For sustained non-powered flight,

L = W*(L/D)/sqrt(1 + (L/D)^2)
D = W/sqrt(1 + (L/D)^2)

For non-constant speed, Wingsuit Equations are needed. The calculated lift and drag vs. time can be seen in the graphs of my jumps above. How these calculations are done, is explained in the article How L/D Magic Works: once the "magic" coefficients of lift and drag Kl and Kd are found, lift and drag can be calculated as:

L = W·Kl·V^2
D = W·Kd·V^2

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!

Bluhdow

a hybrid version with partial UL construction, and partial non-UL for durability

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".

LeeroyJenkins

Where is your 3D flow simulations and modeling?

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.

Skwrl

I’m really curious if all of this extensive research has ever been applied to wingsuit performance? I mean, given this information, shouldn’t you be able to figure out a mode of flight that out-performs everyone? How do your flights compare to typical performance suit fliers?

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.

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 (BFL #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!

Correction to #7:

http://web.mst.edu/~spaceg/2017_annual_meeting/2017%20Reports/2017_MOSGC_Ferguson.pdf

// 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...

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)

(moved to a new thread)

LeeroyJenkins

There has been scientific research done on modern wingsuits

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.

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

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.

dpreguy

The term "Reverse Engineering" is wordsmithing to cover what it really is: Stealing.

If one's intellect and design skills are so poor that they can't make a product of their own...well, I guess they just steal from the guy who did. And to make stolen copies and sell them?...shame on you.

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.

VectorBoy

Yuri Stop being ridiculous just go buy a squirrel, seriously!

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'!

Quote

Now if you want a first generation Vampire 2 of medium size in brand new condition I will sell you one I have. Cheap! I also have a good condition X-2, worn but good condition.

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.