Power Kite Forum

Upwind ability

BeamerBob - 15-12-2008 at 07:12 AM

I had a revelation this weekend with my Blurr 7m. On Sunday, I ran downwind to the point on the island looking for a better angle with the wind and tide. On my way back upwind, I discovered just how far upwind that Blurr will run. When running on hard sand, I was able to hold a line with a reasonable pace within 10-15 degrees of dead upwind. One time as I built apparent wind along with stronger breezes, I got a little overpowered to the point that as I continued to turn upwind to scrub off speed my 285lb body/buggy combo just slid sideways with the back wheels scrubbing continually. The kite wouldn't stop pulling till I took it high.

Is this angle upwind that I had common with decent kites or is the Blurr something special in this department? I wasn't slogging at a walking pace but probably going between 15 and 20 mph.

PHREERIDER - 15-12-2008 at 08:00 AM

THE APPARENT WIND REALLY TAKES OVER ONCE YOU'RE MOVING IN LONGER RUNS. THE ROLLING MASS , ABILITY TO TRACK WITH A STABLE LINE( THE BUGGY FEATURES THIS) THE KITES ABILITY TO DEPOWER ENHANCES ITS UP WIND ABILITY. MECHANICAL LIMITATIONS, AOA .

STEERING UPWIND YOU CAN END UP DRAGGING THE KITE WHICH WOULD HAVE QUITE A BIT OF PULL

dylanj423 - 15-12-2008 at 08:09 AM

I noticed the same with my Blade once at the beach... Flown right next to my Rage 4.7.

I wad to work the hell out of the Rage to get any movement... finally I gave up and walked the board up (wasnt in bug) to a better spot. I decided to pull out the Blade to compare. There was really no comparison. I just put the Blade there, and it did the work, park and ride vs. work-a-lot-for-nothing.

Both decent kites... just different designs. Ther higher the AR, the further forward in the window it will sit... The further forward it sits, the better upwind ability. At least thats how it was explained to me.

Yesterday I was flyin the Rage again, and was keeping upwind fine (in bug) but another of us was about 150 yards further upwind... flying a Jojo with pretty high AR.

Anyhow... it really is amazing the differences in performance that the different kites that we fly have.

acampbell - 15-12-2008 at 08:17 AM

I once spent an afternoon taking compass bearings on wind direction and tire tracks in the sand, hoping to arrive at maximum sustainable upwind tacks. It was interesting in that I found I did better than expected but getting accurate results was impossible due to imprecision of measurements and fluctuating conditions. I reasoned that I would need a recording (over time) GPS feed for direction and speed, synched to concurrent feeds over time of true local wind speed and direction.

In the end I reasoned that time was better spent in the buggy or knocking back a few beers while waiting for someone else with the proper instrumentation to do the job. Any engineering students out there looking for a thesis? I know that Flexifiol has spent a lot of time in the Cabridge wind tunnel and I would love to hear what they have learned about maximum attanable L/D (lift to drag) ratios with modern kites.

According to the Peter Lynn folks, "An L/D of 6 is the high end of what currently available kites attain, representing just over 80 degrees [to the edge of the window]" What was not stated was whether "currenlty available" meant from their product line or the general kiting world including race kites.

Anybodey else have some valid engineering data thei could share? Good thread topic Bobby.

WELDNGOD - 15-12-2008 at 10:00 AM

Dylan , I know I have said this about 100 times, but I'll say it again. Order a AAA kit from flexifoil, it makes the rage totally different kite. You get the same upwind ability.

BeamerBob - 15-12-2008 at 10:26 AM

I might've been conservative in saying 10-15 degrees. The flag was indicating a wind just barely offshore and I was able to go straight up the beach. I wasn't diving away from the wind to generate momentum and then turn back up either. It was park and ride. Well maybe park and grunt is more like it when the wind picked up from time to time. In fact, I was able to gain such a sharp upwind angle that I couldn't turn around and go the other direction on the same line. The kite would fall out of the sky.

tridude - 15-12-2008 at 10:40 AM

remember hand out the window/depower scenario.................KISS..............keep it simple silly! Id say a combo of your ability and the kite. Those Blurrs are one fine piece of engineering. Next outing, Id like a go on the board with one. Hell, I could probably even get upwind on one!:dunno:

BeamerBob - 15-12-2008 at 11:04 AM

yeah tridude, if we can just get you some skills! :D That reminds me of another padawan/jedi moment when on Saturday, I ended up driving the tandem with my mentor Angus on my 6. I mentioned to him the irony of me giving him a ride in it when it was he that got me into this and got me rolling in the buggy.

I was just thinking, the AAA had two knots toward upwindability I could've used as well. Someday I'll have a stretch of days that I can do all the experiments I want to satisfy all my curiosities.

I was also thinking about being able to measure the sustainable angle upwind. You could just pull a line downwind for a few hundred feet from your windsock/flag and then roll across the end of the line and hold your angle as best as you can upwind. Then average the line you maintained and measure the distance between the wind line and the buggy line at a known distance from the end of the string. I can calculate the angle on cad in less than a minute if someone could force themselves to go to the beach and do some "testing and evaluation". ahem. A rolling start when you hit the end of the string would give you the significant advantage of apparent wind.

sunset-Jim - 15-12-2008 at 11:08 AM

To add some more pieces to the puzzle is how powered up you are and also the size of kite. The more powered up you are the more angle upwind can be achieved. Since you would be flying at the edge of the window for that, just fly more powered up than you normally would. And of course avoid the middle of the window...*smile*

And I have yet to experience a 2m kite (or smaller) that has great upwind capability no matter how powered up you are. Even in 35-40 mph winds I've had trouble making a straight line back up the beach, where with a bigger kite in the top of it's range (say a 5m in 20-25mph) it's no problem whatsoever.

acampbell - 15-12-2008 at 11:10 AM

Quote:
Originally posted by BeamerBob
I might've been conservative in saying 10-15 degrees.


Not doubting you but rather noting that it's so difficult to gage

Quote:
In fact, I was able to gain such a sharp upwind angle that I couldn't turn around and go the other direction on the same line. The kite would fall out of the sky.


I think it's a visual thing that is fooling you as seems to happen to me. When going on an upwind tack while facing the inland, it's easier to see your wind sock/ flag/ banner and note the true and apparent wind. Then I find that when I'm on the other tack that faces the water, the waterline takes over as the dominant visulal clue and you tend to gage against that. I find that when I look over my shoulder to get another look at the windsock or flag , that it's harder to get the line right.

That's why I put the little tell-tale on my headsock (peice of bright color yarn on a small soft-plastic mast. When I go upwind facing inland and get a tack angle that feels "in the grove", I note the relative angle of the tell-tale to the buggy downtube and repeat it on the opposite tack. Usually the shoreline is at an angle that I would not have expected.

The fact that, on a sloping beach, one tack is slightly up hill and the other slightly down-hill, can really mess with your sense of effective tacking angles too

BeamerBob - 15-12-2008 at 11:45 AM

Quote:
Originally posted by acampbell
Quote:
Originally posted by BeamerBob
I might've been conservative in saying 10-15 degrees.


Not doubting you but rather noting that it's so difficult to gage

Quote:
In fact, I was able to gain such a sharp upwind angle that I couldn't turn around and go the other direction on the same line. The kite would fall out of the sky.


I think it's a visual thing that is fooling you as seems to happen to me. When going on an upwind tack while facing the inland, it's easier to see your wind sock/ flag/ banner and note the true and apparent wind. Then I find that when I'm on the other tack that faces the water, the waterline takes over as the dominant visulal clue and you tend to gage against that. I find that when I look over my shoulder to get another look at the windsock or flag , that it's harder to get the line right.

That's why I put the little tell-tale on my headsock (peice of bright color yarn on a small soft-plastic mast. When I go upwind facing inland and get a tack angle that feels "in the grove", I note the relative angle of the tell-tale to the buggy downtube and repeat it on the opposite tack. Usually the shoreline is at an angle that I would not have expected.

The fact that, on a sloping beach, one tack is slightly up hill and the other slightly down-hill, can really mess with your sense of effective tacking angles too


No doubt presumed or offense taken. Equally curious to be able to put a number on the angle.
You could be right on the perception thing going downwind. I had not thought of that "angle" (pun intended)

acampbell - 15-12-2008 at 11:56 AM

Quote:
Originally posted by BeamerBob
Quote:
Originally posted by acampbell
Quote:
Originally posted by BeamerBob
I might've been conservative in saying 10-15 degrees.


Not doubting you but rather noting that it's so difficult to gage

Quote:
In fact, I was able to gain such a sharp upwind angle that I couldn't turn around and go the other direction on the same line. The kite would fall out of the sky.


I think it's a visual thing that is fooling you as seems to happen to me. When going on an upwind tack while facing the inland, it's easier to see your wind sock/ flag/ banner and note the true and apparent wind. Then I find that when I'm on the other tack that faces the water, the waterline takes over as the dominant visulal clue and you tend to gage against that. I find that when I look over my shoulder to get another look at the windsock or flag , that it's harder to get the line right.

That's why I put the little tell-tale on my headsock (peice of bright color yarn on a small soft-plastic mast. When I go upwind facing inland and get a tack angle that feels "in the grove", I note the relative angle of the tell-tale to the buggy downtube and repeat it on the opposite tack. Usually the shoreline is at an angle that I would not have expected.

The fact that, on a sloping beach, one tack is slightly up hill and the other slightly down-hill, can really mess with your sense of effective tacking angles too


No doubt presumed or offense taken. Equally curious to be able to put a number on the angle.
You could be right on the perseption thing going downwind. I had not thought of that "angle" (pun intended)


I was thinking about the opposite tack up-wind, but the effects would be the same on both down-wind tacks, with down-wind being even trickier

mgatc - 15-12-2008 at 01:54 PM

Confusius say to all kite flying grasshopper: "Do not over-intellectualize having fun" :bouncy:

tridude - 15-12-2008 at 01:57 PM

Quote:
Originally posted by mgatc
Confusius say to all kite flying grasshopper: "Do not over-intellectualize having fun" :bouncy:


or KISS

bison - 15-12-2008 at 03:45 PM

There is only ONE thing that easily addresses the efficiency of an upwind tack. No matter kite, buggy, conditions, angles, landmarks, etc. All other factors are just over thinking it. Much testing was done concerning this approx. 10 years ago and the result was one number.

Does anyone know what it is? :saint:

acampbell - 15-12-2008 at 03:52 PM

Beer? A/R?

bison - 15-12-2008 at 04:22 PM

Lots of Beer, YES that the magic number. Then you don't care if your going upwind or not! :tumble:

mgatc - 15-12-2008 at 04:45 PM

With enough beer you sine your buggy and not the kite:barf:

BeamerBob - 15-12-2008 at 07:20 PM

Quote:
Originally posted by mgatc
With enough beer you sine your buggy and not the kite:barf:


Now that's funny! What an image you gave me. Stupid grin, (I know) and a weaving buggy. Now that is a worthy experiment.

MadKiteBoy - 15-12-2008 at 07:31 PM

Quote:
Originally posted by BeamerBob
yeah tridude, if we can just get you some skills! :D That reminds me of another padawan/jedi moment when on Saturday, I ended up driving the tandem with my mentor Angus on my 6. I mentioned to him the irony of me giving him a ride in it when it was he that got me into this and got me rolling in the buggy.


I had one of these moments as well.. Angus coached me very well and on the 5m Blur???? i took his PL buggy strait upwind for 50 yrds or so!?!

BeamerBob - 16-12-2008 at 06:57 AM

I guess to get back to my original moment of wonder, is my experience common amongst modern kites? Do many of you from time to time look in amazement at just how far upwind you are able to travel? Before getting into this, I would've guessed I could cut upwind to within 30-35 degrees of directly upwind.

PHREERIDER - 16-12-2008 at 07:12 AM

POWER AT THE EDGE AND HOLD THE LINE WITH OUT CHOKING THE KITE=UPWIND AND ON THE WATER YOU MUST BE AT PLANING SPEED.

AS THE SYSTEM GAINS MOMENTUM THE TENDENCY TO KEEP MAKING YOUR UPWIND LINE STEEPER IS THERE BUT SHORTLY THE SYSTEM CHOKES (DUE TO WATER DRAG). ON LAND YOU END UP DRAGGING THE KITE JUST LIKE WALKING UPWIND WITH THE KITE. YES IT STILL FLIES, STILL "PULLS" BECAUSE YOU ARE MOVING IT. NOT IT(KITE) MOVING YOU.

THE ROLL OUT IN WHEELED MOVEMENT SUSTAINS THE SYSTEM. ENERGY FROM YOUR MASS ACCEL. MOVES THE KITE. IT DOSE GIVE THE FEELING OF FLYING DIRECTLY UPWIND.


A GREAT EXAMPLE OF MOMENTUM SYSTEM IS A HIGH SPEED(BUGGY OR RUNNING) LOW WIND 360. PACE CREATES A VACUUM AT THE TOP OF THE KITE AS IT PASSES DIRECTLY UP WIND

BeamerBob - 16-12-2008 at 09:35 AM

The situation I was in wasn't created by momentum. I was maintaining speed and accelerating if the wind increased. If I was pulling the kite on flat ground, speed couldn't be maintained and I certainly wouldn't accelerate with increased wind.