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World's Fastest Sport


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#1 gruntguru

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Posted 14 October 2013 - 23:18

I just noticed the F1 Racing magazine banner at the top of this screen. Is F1 racing really the worlds fastest sport? I would thing not - what about top fuel drag racing? - Land speed record? - Warbird racing? - Air speed records. All these sports have a human travelling faster than an F1 pilot.

 

Then if we consider the speed of the equipment only, what about rifle shooting?

 

With commercial space travel just around the corner it won't be long before someone creates a competition around that and we will have human competitors travelling faster than the proverbial speeding bullet.

 

Any comments? Faster sports we may not have heard of? Suggestions for faster sports now? Faster sports in the future?



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#2 John Brundage

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Posted 15 October 2013 - 01:13

It is one of the faster MOTOR sports. The fastest would most likely be land speed records. I'm not sure about air racing speeds. 

The fastest sport is ice hockey. 



#3 RogerGraham

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Posted 15 October 2013 - 01:55

Even with motor sport, surely NASCAR and IndyCars are faster in terms of top speeds, and even average speeds when on ovals?



#4 gruntguru

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Posted 15 October 2013 - 02:46

Top fuel dragsters average up to 330 km/hr (top speed 540) on a 1/4 mile track and 290 km/hr (top speed 534) on a 1000 ft track.


Edited by gruntguru, 15 October 2013 - 02:54.


#5 desmo

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Posted 15 October 2013 - 03:49

Fastest to burn through money then?



#6 gruntguru

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Posted 15 October 2013 - 04:17

Interesting point. Expressed in dollars per race, per weekend or per season, top fuel is much much cheaper than F1. Expressed in dollars per racing minute I'm not so sure.



#7 Lee Nicolle

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Posted 15 October 2013 - 05:35

F1 go around corners [and some tracks] faster than most. Straight line is girly compared with Drag Racing. Indy Cars and Nascar often travel faster than F1 too. Proper petrol engine Sports Cars are probably the fasted circuit cars of the lot. Except for straight line!
Record cars is not racing,, there is only one car at a time. Motorsport yes I guess though.

#8 Rob29

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Posted 15 October 2013 - 07:06

Always thought Reno unlimited air race was fastest sporting event-is it still held? I went in 1984 & 96.Not seen any coverage for some years.About 450mph I think!



#9 Bob Riebe

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Posted 15 October 2013 - 16:59

Reno racers exceed 500 mph and have lap speeds in the 490 mph range depending on year one is checking on.



#10 MatsNorway

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Posted 15 October 2013 - 19:40

Fastest on four wheels regarding cornering Gs is probably these fellas.

 

Thats just stupid.


Edited by MatsNorway, 15 October 2013 - 19:40.


#11 Ross Stonefeld

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Posted 15 October 2013 - 20:01

F1 go around corners [and some tracks] faster than most. Straight line is girly compared with Drag Racing. Indy Cars and Nascar often travel faster than F1 too. Proper petrol engine Sports Cars are probably the fasted circuit cars of the lot. Except for straight line!
Record cars is not racing,, there is only one car at a time. Motorsport yes I guess though.

 

Eh? Sportscars, even prototypes, aren't faster than top line open wheelers.



#12 JacnGille

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Posted 16 October 2013 - 01:03

Top fuel dragsters average up to 330 km/hr (top speed 540) on a 1/4 mile track and 290 km/hr (top speed 534) on a 1000 ft track.

From the NHRA website:

 

National Record Holders

Updated 10/07/2013

Professional Categories Class E.T. Speed Date Driver/Car Location

TF 3.701 Seconds   10/08/12 Antron Brown - Pittsboro, IN '12 DSR Mohnton, PA

TF   332.18 MPH 04/15/12 Spencer Massey - Fort Worth, TX '12 DSR Concord, NC


Edited by JacnGille, 16 October 2013 - 01:05.


#13 chdphd

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Posted 16 October 2013 - 18:47

I remember some triva about pelota being the fastest game. See http://en.wikipedia....al_Specialty.29



#14 scolbourne

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Posted 18 October 2013 - 04:46

For un-powered sports it is difficult to beat dynamic RC soaring where speeds of over 500mph are now being reached.

 



#15 mariner

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Posted 19 October 2013 - 12:40

Looking at the latest NHRA top fuel numbers it looks like the AVERAGE acceleration over the new 1,000 ft distance is 4g ?

 

332mph/60mph=5.533*88ft/sec @ 60 mph =487ft per sec/32.2ft/sec =15.51/3.701 seconds = 4.19 G ( if Ive done that right of course.)

 

Cutting the last 320 ft off the length has resulted in hardly any terminal velocity drop - amazing

 

yes , I did note the low ET and top Vmax are not on same run but the overall numbers will be ball park correct.



#16 gruntguru

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Posted 21 October 2013 - 00:58

Cutting the last 320 ft off the length has resulted in hardly any terminal velocity drop - amazing

 

 

 That's because the "Terminal Speed" is very close to the actual top speed of the car ie aero drag at the end of the run is approaching engine power (several thousand horsepower.) This is deliberate. Higher top speed doesn't help much. More downforce - especially early in the run - helps a lot.



#17 Canuck

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Posted 21 October 2013 - 13:10

Seems to me they shortened the track specifically to increase shutoff area because of the speeds. I admit I like that approach to safety vs F1's. Cars are faster than can safely go? Fix the track.

#18 Kelpiecross

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Posted 22 October 2013 - 03:58

For un-powered sports it is difficult to beat dynamic RC soaring where speeds of over 500mph are now being reached.
 


These high-speed gliders really are quite remarkable. One of the interesting things about them is how they manage to fly at roughly ten times the local wind speed. I saw a complicated and (to me) incomprehensible explanation of how it is possible in RCM&E magazine. I suspect it is more likely that it is the "sailing across the wind is faster than with the wind" effect that is most noticeable in sailing "ice-boats" etc.

You would not want to get in the way of one of these things at 500mph.

#19 Canuck

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Posted 22 October 2013 - 05:49

There's nothing I can think of that seems a reasonable thing to stand in front of at 500 miles an hour.

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#20 gruntguru

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Posted 22 October 2013 - 06:46

Maybe a sound wave?

 

Makes me wonder if these guys will be testing the sound barrier sometime soon? The shape of their aircraft would have to change of course.



#21 Kelpiecross

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Posted 23 October 2013 - 03:16

Maybe a sound wave?
 
Makes me wonder if these guys will be testing the sound barrier sometime soon? The shape of their aircraft would have to change of course.


Would sound barrier speeds be possible? Would there not be an effect similar to that which prevents flows past engine valves going supersonic? I suppose it depends on just what the principle is that allows these very high glider speeds.

#22 gruntguru

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Posted 23 October 2013 - 04:52

Would sound barrier speeds be possible? Would there not be an effect similar to that which prevents flows past engine valves going supersonic? I suppose it depends on just what the principle is that allows these very high glider speeds.

Can't see why not.



#23 Bob Riebe

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Posted 24 October 2013 - 04:14

Aircraft not desigined for trans-sonic and super-sonic speeds have serious instability at trans-sonic speeds.

 

Unless the aircraft was designed for these regimes, it would suffer fromt he same problems early supersonic aircraft suffered.

 

Most supersonic aircraft have the glide characteristics of a flat stone.


Edited by Bob Riebe, 24 October 2013 - 04:17.


#24 gruntguru

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Posted 25 October 2013 - 00:59

Yes - and glide ratio is what this is all about. If a glider is in an updraft of say 50 mph vertical and it has a high speed glide ratio of 10:1 it can be doing 500 mph as it corkscrews down - without losing any altitude.

 

So what would be needed is a craft capable of 10:1 glide ratio at supersonic speeds and an updraft of 80 mph or more.



#25 Bob Riebe

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Posted 25 October 2013 - 03:16

Yes - and glide ratio is what this is all about. If a glider is in an updraft of say 50 mph vertical and it has a high speed glide ratio of 10:1 it can be doing 500 mph as it corkscrews down - without losing any altitude.

 

So what would be needed is a craft capable of 10:1 glide ratio at supersonic speeds and an updraft of 80 mph or more.

Supersonic speeds are 700 plus on the deck and six hundred plus tens of thousands of feet higher up.

 

The aircraft would also have to deal with the heat generated at speeds well over a hundred miles an hour faster than they have gone before and sustain speed as they deal with the instability at trans-sonic speeds while lacking the high thrust that supersonic aircraft have to blast through.

Unless one could design a truly area-ruled design that also has a high glide ratio, it is not going to happen and if it does manage to reach transonic speed and is not 

constructed heavily enough it will break apart.


Edited by Bob Riebe, 25 October 2013 - 17:03.


#26 gruntguru

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Posted 25 October 2013 - 07:31

Concorde glide ratio at Mach 2 is 7:1 according to Wikipedia.



#27 Kelpiecross

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Posted 25 October 2013 - 07:59

Yes - and glide ratio is what this is all about. If a glider is in an updraft of say 50 mph vertical and it has a high speed glide ratio of 10:1 it can be doing 500 mph as it corkscrews down - without losing any altitude.
 
So what would be needed is a craft capable of 10:1 glide ratio at supersonic speeds and an updraft of 80 mph or more.


As much as I hate to disagree with the esteemed GG - I don't think the above explanation is correct. If I understand what you are saying I don't think a glider which is falling due to gravity could achieve anything like 500mph let alone supersonic speeds. A WW11 bomb falling vertically from 20,000ft was usually no faster than about 500mph. - I doubt a glider would dive vertically any faster than maybe 100mph at best. I am also not sure the reference to glide ratio is really valid - glide ratios involve distances not speeds.
I suspect the reason these gliders are so bloody fast is a similar effect to vertical axis wind turbines (VAWT apparently) like this blighter:

http://www.platek.com/wind/

Note the glider-like wing size and section. The glider in question on the slope appears to circulate in a near-vertical bank - the overall action of the glider (and its wings) acting like a large (very large) diameter VAWT.

I am not sure if there is at present a generally-accepted theory as to why these gliders are so fast. The only vaguely "official" explanation I have seen involved the glider continually looping from the rising fast-moving air on the slope into the relatively still air in the lee of the slope - apparently picking up a bit of pace each time it completed a circuit - I don't think this theory is correct either.

Edited by Kelpiecross, 25 October 2013 - 08:05.


#28 Bob Riebe

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Posted 25 October 2013 - 17:05

Concorde glide ratio at Mach 2 is 7:1 according to Wikipedia.

Yes and a F-106 once landed itself after the pilot ejected.

The plane was patched and put back into service.

 

That is one of the plusses of a big wing delts.

There may be delta wing gliders but I have not seen one.



#29 Kelpiecross

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Posted 26 October 2013 - 04:22

Yes and a F-106 once landed itself after the pilot ejected.
The plane was patched and put back into service.
 
That is one of the plusses of a big wing delts.
There may be delta wing gliders but I have not seen one.


I have seen a photo of the very similarly-shaped Mirage 3 (of the RAAF) which landed itself on a sandbank in Darwin harbour after the pilot ejected after an engine failure when coming in to land. And another Mirage after an engine failure/ejection apparently not much damaged stuck in the ground like a enormous dart.

#30 gruntguru

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Posted 27 October 2013 - 07:26

As much as I hate to disagree with the esteemed GG - I don't think the above explanation is correct. If I understand what you are saying I don't think a glider which is falling due to gravity could achieve anything like 500mph let alone supersonic speeds. A WW11 bomb falling vertically from 20,000ft was usually no faster than about 500mph. - I doubt a glider would dive vertically any faster than maybe 100mph at best. I am also not sure the reference to glide ratio is really valid - glide ratios involve distances not speeds.

I am not sure if there is at present a generally-accepted theory as to why these gliders are so fast. The only vaguely "official" explanation I have seen involved the glider continually looping from the rising fast-moving air on the slope into the relatively still air in the lee of the slope - apparently picking up a bit of pace each time it completed a circuit - I don't think this theory is correct either.

Speed is the time derivative of distance so glide ratio is horizontal component divided by vertical component - either speed or distance. Interestingly it is also egual to L/D ie the vertical component of force divided by the horizontal component of force.

 

The post you refer to is of course a very much simplified version of what is really going on. However the average airspeed can only be a function of glide ratio (or at least the vertical component of glide ratio) and the vertical component of wind speed - think about it. Of course the radar velocity readings being taken are close to maximum groundspeed. As the glider dives down the slope it is flying directly into the wind so its ground speed will be airspeed minus wind speed. As it approaches the radar, it is travelling upslope and downwind, so the radar reading will be airspeed plus wind speed. In a 50 mph wind the groundspeed of the glider will vary by 100 mph and an average airspeed of 450 mph will produce the radar reading of 500 mph.



#31 gruntguru

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Posted 27 October 2013 - 07:28

There may be delta wing gliders but I have not seen one.

We haven't seen a supersonic glider either. Perhaps there is a link?



#32 JacnGille

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Posted 27 October 2013 - 23:26

There may be delta wing gliders but I have not seen one.

 

The Space Shuttle was a reentry gilder, wasn't it??? :cool:



#33 Greg Locock

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Posted 28 October 2013 - 00:49

and I dare say it was supersonic in the colder air

 

late edit - 1:1 glide ratio at re entry, 2:1 when supersonic, 4.5 :1 in landing configurartion. Now I'm going to read this http://klabs.org/DEI.../1985008580.pdf

 

 


Edited by Greg Locock, 28 October 2013 - 00:56.


#34 Bob Riebe

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Posted 28 October 2013 - 01:05

The Space Shuttle was a reentry gilder, wasn't it??? :cool:

The space shuttle was a delta wing falling object with a glide ratio.

 

A glider does not go only one direction, down.

 

All aircraft have a glide ratio, while FALLING; gliders go UP and down depending on wind currents.


Edited by Bob Riebe, 28 October 2013 - 01:08.


#35 Bob Riebe

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Posted 28 October 2013 - 01:06

We haven't seen a supersonic glider either. Perhaps there is a link?

Is that you speaking to your alter ego, or what?



#36 Kelpiecross

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Posted 28 October 2013 - 04:25

Speed is the time derivative of distance so glide ratio is horizontal component divided by vertical component - either speed or distance. Interestingly it is also egual to L/D ie the vertical component of force divided by the horizontal component of force.
 
The post you refer to is of course a very much simplified version of what is really going on. However the average airspeed can only be a function of glide ratio (or at least the vertical component of glide ratio) and the vertical component of wind speed - think about it. Of course the radar velocity readings being taken are close to maximum groundspeed. As the glider dives down the slope it is flying directly into the wind so its ground speed will be airspeed minus wind speed. As it approaches the radar, it is travelling upslope and downwind, so the radar reading will be airspeed plus wind speed. In a 50 mph wind the groundspeed of the glider will vary by 100 mph and an average airspeed of 450 mph will produce the radar reading of 500 mph.


I am afraid I still have to respectfully disagree. No amount of adding/subtracting wind speed with glide ratios etc. etc. is going to ever give a speed relative to the radar gun of anything near 500mph. With your example what still air glide speed can your glider reach? No where near 450/500mph. As I pointed out a bomb "gliding" (falling) vertically (glide ratio zero) only manages about 500mph.

The mechanism (whatever it might be) behind these very high speeds is a lot more complex than the explanation you give. I still contend that the mechanism probably involves a process similar to a propeller or a wind-driven rotor of some kind (most likely of the VAWT form) rotating in a large circle on the face of the slope.

The "official" explanation of the mechanism is that the glider picks up a little more speed each time it completes a circuit - this theory is worth consideration but personally I don't think it is correct either.

#37 Kelpiecross

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Posted 28 October 2013 - 04:31

and I dare say it was supersonic in the colder air
 
late edit - 1:1 glide ratio at re entry, 2:1 when supersonic, 4.5 :1 in landing configurartion. Now I'm going to read this http://klabs.org/DEI.../1985008580.pdf


News reports of the Shuttle returning to Earth usually report that observers on the ground hear the supersonic boom.

Now that boom from the recent Russian meteorite (which would have involved similar heights and speeds to the Shuttle) - that's what I call a boom.

#38 Kelpiecross

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Posted 08 November 2013 - 04:09

It may be of some interest - the current issue of Aeroplane Monthly magazine reports that the Shuttle when returning to Earth passes through 40,000ft at 18000mph/mach 25. Which is a lot faster at that altitude than I would have guessed.

Edit: I think the magazine meant to write 400,000ft not 40,000ft.

Edited by Kelpiecross, 09 November 2013 - 05:08.


#39 scolbourne

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Posted 13 November 2013 - 13:54

The dynamic soaring RC gliders in the video are flying on the back of the slope in the rotor. This causes there to be two layers of wind , the higher going down the slope and the lower coming back up the slope. This means the glider is effectively flying down wind all the time.

I also can not see how a glider which in a vertical dive can probably achieve only at a guess 300mph can achieve in a 100mph wind anymore than 300 + 100 = 400 mph ground speed.

 

Maybe high altitude helps here or the models can glide faster than I thought. Compression effects at the top of a ridge might help as well like in a venturi.

 

If anyone has any insight into this I am interested in finding out.



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#40 gruntguru

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Posted 13 November 2013 - 23:06

The dynamic soaring RC gliders in the video are flying on the back of the slope in the rotor. This causes there to be two layers of wind , the higher going down the slope and the lower coming back up the slope. This means the glider is effectively flying down wind all the time.

I also can not see how a glider which in a vertical dive can probably achieve only at a guess 300mph can achieve in a 100mph wind anymore than 300 + 100 = 400 mph ground speed.

 

Maybe high altitude helps here or the models can glide faster than I thought. Compression effects at the top of a ridge might help as well like in a venturi.

 

If anyone has any insight into this I am interested in finding out.

For starters I would wager these gliders are heavy.



#41 gruntguru

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Posted 13 November 2013 - 23:30

http://en.wikipedia....Dynamic_soaring

 

So it appears the gliders are exploiting a sharp difference in wind velocity in two adjacent regions (often vertically separated layers) of the atmosphere - Scolbourne is almost right. The extra piece of the puzzle is the energy available every time the model penetrates the boundary between air layers and experiences a significant increase in airspeed. This is converted into kinetic energy (increased groundspeed) by executing a 180* turn to point downwind at which time the glider crosses into the other airstream and experiences yet another increase in airspeed etc etc.



#42 Kelpiecross

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Posted 15 November 2013 - 03:47

http://en.wikipedia....Dynamic_soaring
 
So it appears the gliders are exploiting a sharp difference in wind velocity in two adjacent regions (often vertically separated layers) of the atmosphere - Scolbourne is almost right. The extra piece of the puzzle is the energy available every time the model penetrates the boundary between air layers and experiences a significant increase in airspeed. This is converted into kinetic energy (increased groundspeed) by executing a 180* turn to point downwind at which time the glider crosses into the other airstream and experiences yet another increase in airspeed etc etc.


The Wiki article (and many other similar items on the internet) has become the "official" explanation for the high speed "dynamic soaring" effect. It may very well be correct but I remain not totally convinced. I cannot see how this explanation could give a speed greater than the maximum wind speed in the area. Any object running parallel to the prevailing wind cannot exceed the velocity of the wind itself.
However there is one classic way where an aerofoil (or a sail etc.) can exceed the local wind velocity - it has to run at an angle (or a right angle) to that wind. There are many classic sail-type examples but the main one would have to be a typical propeller "windmilling" in the prevailing air flow. In this case the aerofoil section is moving normal to the wind. The speed of the propeller tip (or any other part of the propeller) is proportional to the wind speed but is not necessarily that of the wind speed itself. I would suggest that the glider picks up speed each time it climbs or dives vertically across the airstream until it reaches what would be equivalent to its "propeller" or "rotor" speed. The glider essentially acts as a VAWT rotor (but one which is lying on its side) of the type I quoted earlier in this thread.

#43 gruntguru

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Posted 15 November 2013 - 06:03

The VAWT analogy is pretty close except that you can't operate a VAWT without mounting to a stationary object (the ground). The glider needs something to "react" the wind force. If the wind profile was constant velocity everywhere, an observer located in the glider would not be able to distinguish any difference from still air (unless he looked at the ground).

 

The shear boundary and the two different wind fields, give the glider something to "push" against.



#44 Kelpiecross

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Posted 15 November 2013 - 10:57

The VAWT analogy is pretty close except that you can't operate a VAWT without mounting to a stationary object (the ground). The glider needs something to "react" the wind force. If the wind profile was constant velocity everywhere, an observer located in the glider would not be able to distinguish any difference from still air (unless he looked at the ground).
 
The shear boundary and the two different wind fields, give the glider something to "push" against.


As you say - for an aerofoil (or sail) to proceed across wind it needs to have something to "react" against - otherwise it would just progress downwind and not across the wind. In the case of the glider I envisage the considerable forward momentum (as you imply these gliders are very heavy) of the glider as being enough to, at least for a short period, to hold it against the wind as it emerges from the relatively still air and sticks its nose up into the fast-moving air. It is not uncommon to see a model plane flying into the wind suddenly pitch up and accelerate upwards for at least a short distance. Kites perform a similar trick - but they have their tether string to react against.

Edited by Kelpiecross, 15 November 2013 - 10:58.


#45 gruntguru

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Posted 15 November 2013 - 21:18

On reflection, I think the VAWT is a good analogy - actually two semi-VAWTs - 180* each. The reaction force in each is the considerable centrifugal force as the glider performs a very tight 180* turn.



#46 Johan Lekas

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Posted 18 November 2013 - 11:14

An other analogy is a bicycle riding "loops" over a fixed floor and a moving belt, like the plane does in the wiki animation (http://upload.wikime...ted_Diagram.gif)

I don't see the need for anything, except the floor and the belt, to react against?



#47 scolbourne

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Posted 19 November 2013 - 10:23

It would help in understanding dynamic soaring to know what air speed the gliders could achieve in a dive in still air. We might be making this much too complicated when it is really a case of simply adding air speed on to the reverse wind speed (rotor).

As far as I can understand it,  if the glider is moving faster than the wind (relative to the ground) it should be experiencing drag all the time. It will accelerate up to its max air speed but can it get any faster ?

 

I think another way to view this is that when the glider moves into the other air stream it is effectively sailing across the wind using its momentum instead of a sailing boats centreboard or a kites line to act against.

 

Page 36 of this document is one possible explanation.

 

http://www.rcspeeds....2012-04Orig.pdf


Edited by scolbourne, 28 November 2013 - 13:05.