0
yuri_base

The Wingsuit Theory, or How to fly like an eagle while barely moving on the couch

Recommended Posts

Here is another illustration of effects of wingloading in WS BASE. We apply wingsuit equations to two jumpers of the same size, but different exit weight: 180lbs and 260lbs. They both have L/D=2.5 (the model assumes that it's constant throughout the flight for simplicity). The lighter jumper has sustained speeds 100mph forward, 40mph down; the heavier jumper - 120mph forward, 48mph down. (The speed is proportional to the square root of wingloading: 48mph/40mph = sqrt(260lbs/180lbs).)

As can be seen from the graphs, the lighter jumper has a significant advantage in distance covered. The most dramatic difference happens for relatively low walls with 2000ft of usable altitude: the light one flies 3000ft horizontally, while heavy one only 1500ft. The heavier jumper's planeout kicks in later, but lasts longer. At 3000ft of usable altitude, the difference in horizontal distance reduces to about 800ft. At 4000ft, the difference is about 1000ft and stays constant after that. The average glide ratio for such a flight, if we subtract 500ft for starting to fly, will be 2.3 (8000ft/3500ft) for the light guy and 2.0 (7000ft/3500ft) for the heavy.

So if you're heavy, you naturally suck! On the other hand, if you're heavy and flew to the same spot as a light guy, he sucks (his L/D is lower).

Now, what's that Deadmanwalking's big wall diet? ;)
Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

Share this post


Link to post
Share on other sites
Exit technique has a major affect on how soon a flight is initiated. I have seen skinny light people in big suits do worse than 200 lb folks in beginner suits. It was also evident(to anyone watching the exit technique) why the skinny person was burning up so much altitude to start flight.

Personal observation.
===============
V1@90kgs and Phantom@72kgs...flight reached pretty close to max in 10-12 secs. It is my belief based on being in between 72 and 90 kgs(nearly 6'2") and having flown the Phantom throughout this range that 72 kg is too light. It was more comfortable to fly when weighing 78-80 kg.

Kris.

Share this post


Link to post
Share on other sites
3.567 is the magic L/D at which wingsuit will fly horizontally after a natural planeout on a BASE jump. With L/D higher than that, you'll even temporarily go up.

In the attached example, wingsuit equations are solved using Mac's Grapher utility (Grapher file with WSE is attached in .zip) for a range of L/D's and polar curves (horizontal axis - horizontal speed, vertical axis - vertical speed) are plotted. Starting with zero initial speed, the vertical speed momentarily becomes zero if L/D = 3.567. Running the equations for a wider range (L/D from 0 to 25) creates an interesting 'psychedelic' picture. :)

The race to achieve the magic L/D = 3.567 started today. If you're not in, you're not revolutionary enough! ;)
Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

Share this post


Link to post
Share on other sites
Another magic L/D discovered: 2.631 is L/D sufficient for level planeout after reaching maximum possible vertical speed while spiraling headdown.

Based on the assumption that all of lift serves as centripetal force and that drag simply equals to weight, the maximum achievable speed (while flying fully spread out, and with the same AoA as for given lift/drag coefficients Kl and Kd) is Vymax = 1/sqrt(Kd). Feeding this initial speed into WSE produces this magic L/D = 2.631, which is independent of wingloading and actual values of lift and drag coefficients (i.e., it's universal - applicable to all flyers).

All in all, we have 3 magic, universal L/D's:

1.414 is L/D to achieve maximum horizontal speed possible

2.631 is L/D to achieve level planeout after reaching maximum vertical speed by spiraling down

3.567 is L/D to achieve level planeout after zero-speed exit

It's pure fucking magic!!! :)
Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

Share this post


Link to post
Share on other sites
C# class library that solves WSE. Open the solution in Visual Studio 2005, hit Ctrl-F5 and read the important message from Che Guevara.

Enjoy the shrooms! ;)
Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

Share this post


Link to post
Share on other sites
To celebrate the upcoming 10th Anniversary of Wingsuit Equations -

[inline WSE.png]

[inline 10th.jpg]

- L/D Magic and all of its optional components will be free on December 7, 2016. Get your piece of Pure Fucking Magic while supplies last!

Download -----> [inline LDMagic.png]


L/D Magic now supports 10Hz sample rate with Bad Elf GPS Pro and Dual XGPS160, as well as 5Hz with Dual XGPS150A and Emprum UltiMate GPS.

The app is iPhone-only. For Android and Windows phones, I have a simplified app called L/D Vario, see this thread. Note that while L/D Magic has two modes of operation - one with the phone mounted on a vane in free stream, using accelerometer to measure L/D, and the other with the phone in pocket, using high-speed external GPS; L/D Vario works only on a vane. Here's an example with LG G Watch R:

https://www.youtube.com/watch?v=u_iPSSV-5qY

(Also, a fast built-in pressure sensor is highly desirable to get accurate measurements of the polar curve speeds. LGGWR has one at 90Hz; the champion as of now is Nixon the Mission smartwatch with 165Hz sample rate reported by a user.)

Another difference between L/D Vario and Magic is that the former does not require exit at exact moment of "c-ya!" count like the latter; it works continuously. L/D Magic requires precise start because it needs a start point to integrate WSE and run Kalman filter; thus it's more suited for BASE as it's hard to exit at exact moment from the airplane.

Vane: you need to make one yourself for your device. It needs to be balanced neutrally on its axis and mounted on a pole at least ~2ft from the belly (helmet is not a good place for this) so that the angle of the relative wind hitting the vane is the same as the angle of your velocity relative to the air mass (i.e. the vane is in true free, undisturbed stream). Like this:

[inline Vane.jpg]

Any questions about the use, feel free to ask here or by email in my profile.

WSE are an azaming (i.e. so amazing that can't even spell right) phenomenon - they're so simple to derive that it's like kicking a rock with your foot and boom! it splits in half and a 100-karat diamond rolls out of it! And in 10 years, I derived so much useful stuff from it that it fills several Moleskins with yet unpublished gems waiting their time:

[inline Moleskins.jpg]

And it shows no signs of depletion. For example, recently I found a more accurate estimate of the L/D necessary to achieve maximum sustained horizontal speed: 1.3 for wingsuits capable of max L/D of ~3.0 (the previous result from 10 years ago was square root of 2; it turns out this is for infinitely high L/D) - useful for those participating in speed competitions. The recent idea of FAP (Fast, Accelerated Proximity) was also fueled by WSE.

It almost feels spiritual: it can't be so simple, so beautiful, so powerful... but it is! I don't know if there's God or we're living in a computer simulation run by another civilization, but to me WSE ring that tiny bell that it's all not random... all these big walls, diving boards as if specifically made for BASE... there must be The Old Dude in White Wingsuit Sitting on a Cloud watching for us! :)

Beeeeeeeeeeeeeeeeeeeeeeeeeeer and azaming flights, everyone!!!

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

Share this post


Link to post
Share on other sites
"One more thing..." Rockdrop Pro also uses Wingsuit Equations, so the celebration wouldn't be complete without this child of WSE. So, Rockdrop Pro app will also be free on December 7th.

Download Rockdrop Pro here: Android+Wear ~ iOS ~ Windows

However, for Android users it will require a bit of work: unfortunately, it's not possible to make a paid app on Play Store temporarily free; free is permanent. So, you'll need to use a promo code. I've generated 357 promo codes (out of 500 allowed for the quarter) - remember, 3.57 is a magical L/D, thus, 357 codes. The list of promo codes is attached. If one doesn't work on December 7th, it means it was taken already, try a different one.

The other children of WSE - L/D Vario (Android+Wear ~ iOS ~ Windows), Wingsuit FAP (Android ~ iOS ~ Windows), and Wingsuit Studio (Win 32) - are already free.

Flying smart is the new cool, so join the party!!! :)
Doors open on December 7 at 12:00am UTC, close on December 8 at 12:00am UTC.
Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account. It's free!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
0