Author Topic: Mess with your minds: A wind powered craft going faster than a tail wind speed.  (Read 147367 times)

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Offline electrodacus

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The only way you get that 11W on the output is if you add another power supply in parallel or series with the first one.

Yes, that's the principle.  The propeller and the wind are 'in series', so to speak.  If you like bad analogies, you can compare the various 'speed' of the players with voltage.  If the wind and the vehicle are at the same speed you can compare that to a power source and a sink--say a charger and battery--that are both at the same voltage so that no power flows.  But if you add an isolated DC-DC converter across the source and then put its output in series between the source and sink, now power will flow.

So the wheel-to-propeller link can be considered as a sort of boost converter that allows power to go from an original source that is the same or even lower voltage than the sink.

I provided this analogy to show that if the only input is the wheel you can not get 11W out of just 5.5W at input.
And to continue with this analogy when vehicle is below wind speed there is extra power available from wind but at wind speed that power available from wind is 0W thus since the example was when vehicle speed = wind speed output of the propeller can not be more than 5.5W input from the wheel thus no acceleration possible. In real world blackbird there is the stored pressure differential energy that provides the power to cover the losses plus extra for acceleration.
So the point I made is that a energy storage device is needed to exceed wind speed directly down wind and that is the pressure differential with you do not understand thus try to avoid.

And to be clear a boost DC-DC converter outputs will be lower power than input and also any boost converter will have energy storage devices either an inductor a capacitor or both.

Online Alex Eisenhut

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And to be clear a boost DC-DC converter outputs will be lower power than input and also any boost converter will have energy storage devices either an inductor a capacitor or both.

What about a DC-DC converter with a solar panel providing 1 watt in sunlight added to the output, and used outside?

What then? How much power do you measure at the input vs the output?

Suppose a 5V to 12V boost converter you can buy on eBay, it's 90% efficient. Power to the input from a USB power pack at 5V with enough current capacity. I added a solar panel and circuitry to add the power to the output. I used it outside in sunlight no clouds with the solar panel pointed at the sun.

I measure 12V at 1A through a resistor. Do you agree this is 12 watts of output power?

Then a 90% efficient supply would need 13.3W, so 2.7A at 5V.

But 1W is coming from the solar panel.

How much current will the supply actually need at 5V?

2.5A? Why? 12W at 90% efficiency = 13.3W needed, MINUS 1W from the panel, 12.3W needed from the 5V supply.

Clear? The *SUN* has added power. Happy?
Hoarder of 8-bit Commodore relics and 1960s Tektronix 500-series stuff. Unconventional interior decorator.
 

Offline electrodacus

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And to be clear a boost DC-DC converter outputs will be lower power than input and also any boost converter will have energy storage devices either an inductor a capacitor or both.

What about a DC-DC converter with a solar panel providing 1 watt in sunlight added to the output, and used outside?

What then? How much power do you measure at the input vs the output?

Suppose a 5V to 12V boost converter you can buy on eBay, it's 90% efficient. Power to the input from a USB power pack at 5V with enough current capacity. I added a solar panel and circuitry to add the power to the output. I used it outside in sunlight no clouds with the solar panel pointed at the sun.

I measure 12V at 1A through a resistor. Do you agree this is 12 watts of output power?

Then a 90% efficient supply would need 13.3W, so 2.7A at 5V.

But 1W is coming from the solar panel.

How much current will the supply actually need at 5V?

2.5A? Why? 12W at 90% efficiency = 13.3W needed, MINUS 1W from the panel, 12.3W needed from the 5V supply.

Clear? The *SUN* has added power. Happy?

We are drifting in all sort of analogies but to try and answer what happens imagine that vehicle with the solar panel having the solar panels rotate away from the sun as the speed increases. That is what happens to a wind powered vehicle that drives directly downwind.

As for solar panel + boost converter the output of the boost converter will be always lower than 1W if solar panels outputs 1W

Why are you involving a battery ? Have you not mentioned there is no energy storage device or external power source ?


Here are the correct equations for wind power available to a vehicle traveling directly down wind
0.5 * air density * area * (wind speed - vehicle speed)^3    yes this is the correct equation. Notice how you have highest power at low vehicle speed and power drops to zero by the time vehicle speed equals wind speed.





Online IanB

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Here are the correct equations for wind power available to a vehicle traveling directly down wind
0.5 * air density * area * (wind speed - vehicle speed)^3    yes this is the correct equation. Notice how you have highest power at low vehicle speed and power drops to zero by the time vehicle speed equals wind speed.

But why is this the correct equation?

Please derive this equation step by step from first principles, stating any assumptions made at each step.
 

Offline Labrat101

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@electrodacus
A Bumblebee can't fly .!!
Same as electrodacus can't  believe a simple
Solution.  That if everyone says the 🌎 is round .
He would argue its flat because my spirit level says so .. :palm:
So if everyone here has proven it does work .
Plus there has been a video showing it works
. There for Bumblebee can fly also faster the tail wind .
Your ideas of what is true and false , was is, and what can . 
  Maybe beyond your comprehension .
  It wouldn't matter if Albert Einstein could tell you that your wrong .
You are living in some sort of self denial.
Get over it and except that it can and does work.

Solution is not simple and I never believe anything I need to understand.
All works as shown in tests and is fully described by my theory.
On the other hand the equations you proposed do not predict what happens in real tests.
You Quoted ::
  Solution is not simple and I never believe anything I need to understand.   Explain Just ONE thing that YOU do UNDERSTAND   :-DD
On the other hand the equations you proposed do not predict what happens in real tests.  .. What equations do you see in my quote??
   It's Text .. ie   NO numbers. 
Also you quoted this ::
   Luckily there are people that understand all this they just seems to be unwilling to waste time with you (all).
 Maybe all your People you Know . Have all ready been institutionalised and not allowed out to the general public .  :-DD
« Last Edit: December 18, 2021, 11:04:48 pm by Labrat101 »
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Online bdunham7

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We are drifting in all sort of analogies but to try and answer what happens imagine that vehicle with the solar panel having the solar panels rotate away from the sun as the speed increases. That is what happens to a wind powered vehicle that drives directly downwind.
 

I'll agree that analogies are often problematic, but that one is the worst I've seen in a long time.

Quote
Here are the correct equations for wind power available to a vehicle traveling directly down wind
0.5 * air density * area * (wind speed - vehicle speed)^3    yes this is the correct equation. Notice how you have highest power at low vehicle speed and power drops to zero by the time vehicle speed equals wind speed.

So surely you agree that the total available wind power at a certain point (no vehicle or sail involved) is 0.5*airdensity * windspeed3, correct?

So where does the rest of that wind power go if you can only get the fraction of it that your formula specifies?  That power is still there somewhere, isn't it?
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline electrodacus

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Quote
Here are the correct equations for wind power available to a vehicle traveling directly down wind
0.5 * air density * area * (wind speed - vehicle speed)^3    yes this is the correct equation. Notice how you have highest power at low vehicle speed and power drops to zero by the time vehicle speed equals wind speed.

So surely you agree that the total available wind power at a certain point (no vehicle or sail involved) is 0.5*airdensity * windspeed3, correct?

So where does the rest of that wind power go if you can only get the fraction of it that your formula specifies?  That power is still there somewhere, isn't it?

Please read again my formula as you forgot a very important part and that is the area that wind pushes against.
0.5 * air density * area * windspeed3
This is the formula anyone designing a wind turbine will use except that is is ideal 100% of available wind power and to this they need to add the turbine efficiency usually around 40% and the generator efficiency that can be over 90%
For a vehicle driving directly down wind ideal case all you need is to subtract vehicle speed from wind speed since wind speed relative to vehicle is what can power the vehicle.
This formula
0.5 * air density * area * (wind speed - vehicle speed)3 is what will apply to any wind only powered vehicle driving directly downwind.
This is also the ideal case so absolutely max that is available to the vehicle meaning that if you do not add an energy storage device to this vehicle or some external energy source like gasoline and an engine then your vehicle can not exceed wind speed.
For direct downwind blackbird is clear to me that energy is stored in pressure differential generated by the propeller and that is what allows it to exceed wind speed even if it may be for just a few minutes depending on the design, how fast it will use that stored energy.

Online bdunham7

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Please read again my formula as you forgot a very important part and that is the area that wind pushes against.
0.5 * air density * area * windspeed3
This is the formula anyone designing a wind turbine will use except that is is ideal 100% of available wind power and to this they need to add the turbine efficiency usually around 40% and the generator efficiency that can be over 90%
For a vehicle driving directly down wind ideal case all you need is to subtract vehicle speed from wind speed since wind speed relative to vehicle is what can power the vehicle.
This formula
0.5 * air density * area * (wind speed - vehicle speed)3 is what will apply to any wind only powered vehicle driving directly downwind.
This is also the ideal case so absolutely max that is available to the vehicle meaning that if you do not add an energy storage device to this vehicle or some external energy source like gasoline and an engine then your vehicle can not exceed wind speed.

Mea culpa, I forgot to put in 'area'.  But you've dodged the actual question.  Since all of the energy in the first question represents the total wind energy available for that particular area and the second equation represents only part of that energy, where does the rest of it go?
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline Brumby

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Clearly shows you do not understand power and energy. 20km/h ~ 5.5m/s
If you take 5.5W form the wheel (1N * 5.5m/s) and put all that in to propeller (ideal case) the most propeller can output is 5.5W
Using this, you have 5.5W spinning a propeller.  This propeller creates a thrust force against an air mass which is stationary with respect to the vehicle.

Quote
thus no acceleration possible even in ideal case.
How can a non-zero force NOT create a change in velocity?
 

Online IanB

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It's really necessary to work with power, rather than energy.

For a vehicle to travel at any steady speed, v, the power it requires is the power required to overcome the frictional resistance--the rolling resistance on the ground and the drag from the surrounding air.

Let's suppose that a vehicle wants to travel at a speed, v, that is faster than the wind, then it will require some motive power, Pv.

If a vehicle can obtain at least that much power from the wind, using a turbine or other mechanism, then it can travel at that speed. It becomes an engineering problem of how to design that mechanism, that will necessarily include such items as turbines, fans, gears, shafts, even possibly a motor-generator combination.

There is no violation of conservation of energy implied, since clearly the wind has unlimited power available (if you want more power, just use more area for your fan/turbine).

To be clear, sailors know this, since they routinely sail downwind faster than the wind, as noted by my example earlier in the thread. If the wind speed is 20 mph due west, then racing yachts can travel 20 miles due west at an average speed greater than 20 mph. And they can do this indefinitely. Energy storage cannot be claimed for a boat that is travelling for an hour or more at these speeds.

(Specifically, if point B is 20 miles due west of point A, and the wind is blowing at 20 mph due west, then a boat can travel from A to B in less than 1 hour.)
« Last Edit: December 19, 2021, 01:44:36 am by IanB »
 

Offline electrodacus

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Mea culpa, I forgot to put in 'area'.  But you've dodged the actual question.  Since all of the energy in the first question represents the total wind energy available for that particular area and the second equation represents only part of that energy, where does the rest of it go?

The equation is for wind power available to vehicle not wind energy. Wind power will be stored over time as kinetic energy and pressure differential in the case of direct downwind blackbird.
If there was just kinetic energy like it is the case with a sail vehicle then that vehicle could not exceed wind speed unless it was driving at an angle and not directly down wind.
You all seems to be confused on what power and energy is so most of your questions do not make sense.
I will rather talk with GPT-3 :)

Offline electrodacus

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It's really necessary to work with power, rather than energy.

For a vehicle to travel at any steady speed, v, the power it requires is the power required to overcome the frictional resistance--the rolling resistance on the ground and the drag from the surrounding air.

Let's suppose that a vehicle wants to travel at a speed, v, that is faster than the wind, then it will require some motive power, Pv.

If a vehicle can obtain at least that much power from the wind, using a turbine or other mechanism, then it can travel at that speed. It becomes an engineering problem of how to design that mechanism, that will necessarily include such items as turbines, fans, gears, shafts, even possibly a motor-generator combination.

There is no violation of conservation of energy implied, since clearly the wind has unlimited power available (if you want more power, just use more area for your fan/turbine).

To be clear, sailors know this, since they routinely sail downwind faster than the wind, as noted by my example earlier in the thread. If the wind speed is 20 mph due west, then racing yachts can travel 20 miles due west at an average speed greater than 20 mph. And they can do this indefinitely. Energy storage cannot be claimed for a boat that is travelling for an hour or more at these speeds.

(Specifically, if point B is 20 miles due west of point A, and the wind is blowing at 20 mph due west, then a boat can travel from A to B in less than 1 hour.)

Yes an ideal vehicle will need to power to maintain speed as there is no fiction loss.
You just forget that wind power is available to vehicle only as long as a direct down wind vehicle speed is lower than wind speed.
You have unlimited energy to use as long as you stay below wind speed.
As soon as you exceed wind speed there is no more wind power available so to do that in the first place you need some earlier stored energy.
The way they will travel with a sail faster than wind will be to drive at an angle to the wind that way you still have access to wind power since vehicle while faster than wind is not faster direct down wind (it is a geometry thing) so boat is faster but wind / air particles can still reach the boat to push as boat is still slower in the direction of the wind. Then the boat once it charged energy as kinetic energy can turn strait down wind and if friction losses are low it can drive for some amount of time direct down wind faster than wind while the speed will continually drop and of course so will the kinetic energy.

Offline electrodacus

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Using this, you have 5.5W spinning a propeller.  This propeller creates a thrust force against an air mass which is stationary with respect to the vehicle.
How can a non-zero force NOT create a change in velocity?

Yes but those 5.5W will not create more than 5.5W at the propeller output. So the kinetic energy / speed reduction to get those 5.5W will require the same 5.5W just to be where you started from in ideal case.
If you have no wind power available to help or no stored energy then you can just not accelerate above wind speed. Since wind power is not available above wind speed for a vehicle traveling directly down wind then energy storage is the only option or of course some external energy source maybe solar if you want.

Online IanB

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...as boat is still slower in the direction of the wind.

No, the boat is faster than the wind in the direction of the wind. That is the whole point of how the boat can travel 20 mph downwind in less time than the wind takes to cover the same distance.

(If you disagree with this, you will have to tell the sailors that what they are doing is impossible. They will be very interested to hear that.)
 

Online bdunham7

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The equation is for wind power available to vehicle not wind energy. Wind power will be stored over time as kinetic energy and pressure differential in the case of direct downwind blackbird.
If there was just kinetic energy like it is the case with a sail vehicle then that vehicle could not exceed wind speed unless it was driving at an angle and not directly down wind.
You all seems to be confused on what power and energy is so most of your questions do not make sense.
I will rather talk with GPT-3 :)

OK, you're right.  It's turtles all the way down.
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline electrodacus

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...as boat is still slower in the direction of the wind.

No, the boat is faster than the wind in the direction of the wind. That is the whole point of how the boat can travel 20 mph downwind in less time than the wind takes to cover the same distance.

(If you disagree with this, you will have to tell the sailors that what they are doing is impossible. They will be very interested to hear that.)

Let me try this again. In ideal case a boat can get to 2x even more wind speed at an angle and then since there is no friction it can just turn directly down wind and travel forever at 2x. In real world there is friction so sailor will get the boat to speed means increased kinetic energy (stored kinetic energy) and then it can turn straight and for a few minutes stay above wind speed as kinetic energy and boat speed reduces then he can turn again to an angle to get to speed and repeat. If friction is sufficient low average may be higher than wind speed but even if it is not above wind speed it is still faster as most sail boats direct downwind can do just 0.5x wind speed.
So in this case kinetic energy is used as energy storage.  In case of blackbird driving at an angle is not allowed so kinetic energy can not be used as energy storage in the same way it is used in the example above.

Offline electrodacus

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OK, you're right.  It's turtles all the way down.

It is.
« Last Edit: December 19, 2021, 04:40:51 am by electrodacus »
 

Offline Brumby

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Using this, you have 5.5W spinning a propeller.  This propeller creates a thrust force against an air mass which is stationary with respect to the vehicle.
How can a non-zero force NOT create a change in velocity?

Yes but those 5.5W will not create more than 5.5W at the propeller output. So the kinetic energy / speed reduction to get those 5.5W will require the same 5.5W just to be where you started from in ideal case.
I know exactly what you are saying here ... and it is what you would naturally expect from applying intuitive thinking.

However, the mechanism utilises a mechanical advantage (if you will) with the power of the wind augmenting the effectiveness of that 5.5W.
 

Online IanB

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...as boat is still slower in the direction of the wind.

No, the boat is faster than the wind in the direction of the wind. That is the whole point of how the boat can travel 20 mph downwind in less time than the wind takes to cover the same distance.

(If you disagree with this, you will have to tell the sailors that what they are doing is impossible. They will be very interested to hear that.)

Let me try this again. In ideal case a boat can get to 2x even more wind speed at an angle and then since there is no friction it can just turn directly down wind and travel forever at 2x. In real world there is friction so sailor will get the boat to speed means increased kinetic energy (stored kinetic energy) and then it can turn straight and for a few minutes stay above wind speed as kinetic energy and boat speed reduces then he can turn again to an angle to get to speed and repeat. If friction is sufficient low average may be higher than wind speed but even if it is not above wind speed it is still faster as most sail boats direct downwind can do just 0.5x wind speed.
So in this case kinetic energy is used as energy storage.  In case of blackbird driving at an angle is not allowed so kinetic energy can not be used as energy storage in the same way it is used in the example above.

Here's a picture. This is with friction, traveling at a steady speed, with no speeding up or slowing down, and no kinetic energy. At no time is the boat traveling downwind slower than the wind speed. The boat can tack like this forever, always going faster than the wind, and never going below the wind speed. This is what real boats can do, in the real world, with lots of evidence to prove it.

If you think this is not possible, you will have to argue with the people who sail these boats.

 
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Online IanB

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This is how Blackbird can do the same thing:
 

Offline electrodacus

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Quote
Yes but those 5.5W will not create more than 5.5W at the propeller output. So the kinetic energy / speed reduction to get those 5.5W will require the same 5.5W just to be where you started from in ideal case.
I know exactly what you are saying here ... and it is what you would naturally expect from applying intuitive thinking.

However, the mechanism utilises a mechanical advantage (if you will) with the power of the wind augmenting the effectiveness of that 5.5W.

There is no mechanical system or even non mechanical that can output any more than the input in therms of power.
You can adjust the ratio between force and speed but power on output will need to remain the same (ideal case) or less (real world).
All you all did was experience that vehicle exceeded wind speed and came up with wrong explanation of why that happened when the obvious solution was to look for an energy storage device.
It is exactly like those motor generators setups where a motors drives a generator usually trough a gear ratio change and generator supplies the motor.
There people use tricks like adding a large flywheel (mechanical energy storage device) or even hide a battery to trick people.
Here there was no intent in deceiving (at least I do not think it was) but just did not understood that there is an energy storage device and that is what powers the vehicle above wind speed.
The sad part is that people with a PhD in physics get tricked by this. That university professor that lost the bet (his fault for gambling) said nothing wrong in Derek's video but since it was unable to explain how the treadmill prototype worked it was forced to pay the money not to be seen as not honoring his obligations.  He should have asked for help and try to understand why it works then make that information public.

Unfortunately school is mostly for those that can memorize facts and equations an understanding is completely irrelevant.     

Offline electrodacus

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This is how Blackbird can do the same thing:

Nope that image is possible for some moments due to initial stored kinetic energy or maybe higher wind gust.
It seems sailors do not have just stories about large fish and Mermaids.
But keep in mind the main discussion here is about blackbird that is not allowed to travel at any angle other than direct down wind.

Online bdunham7

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But keep in mind the main discussion here is about blackbird that is not allowed to travel at any angle other than direct down wind.

Hmmm.  Is that true for the propeller blades?  Are they going straight downwind?
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline Brumby

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There is no mechanical system or even non mechanical that can output any more than the input in therms of power.
It's not outputting any more.  It's extracting power from a wheel system that is travelling at one speed (frame of reference is the ground) and then applying that power to a propeller system travelling at a different speed (frame of reference is the wind).

This is the concept you continually dismiss, bypass or ignore.  It is THE heart of the Blackbird doing what it can - and has - done.  By refusing to even consider this concept as a possibility you are condemned to remain ignorant.


... when the obvious solution was to look for an energy storage device.
No.  The obvious solution would be to see if you could find out a way it COULD work.  This is something you continually refuse to do.

It is clear you cannot think outside your own comfort zone - which means you are destined to remain ignorant of the many possibilities that exist.

Quote
It is exactly like those motor generators setups where a motors drives a generator usually trough a gear ratio change and generator supplies the motor.
It's nothing like that - but you seemed hung up on standing your ground with this concept and your totally flawed "modelling" of that.

Quote
There people use tricks like adding a large flywheel (mechanical energy storage device) or even hide a battery to trick people.
Here there was no intent in deceiving (at least I do not think it was) but just did not understood that there is an energy storage device and that is what powers the vehicle above wind speed.
Just because you keep saying it, doesn't make it true.

Quote
The sad part is that people with a PhD in physics get tricked by this.
No.  The sad part is the people who think they know better - and and either won't listen or cannot comprehend an objective process to describe what is going on.

Quote
That university professor that lost the bet (his fault for gambling) said nothing wrong in Derek's video but since it was unable to explain how the treadmill prototype worked it was forced to pay the money not to be seen as not honoring his obligations.  He should have asked for help and try to understand why it works then make that information public.
Poor, dumb professor.

Quote
Unfortunately school is mostly for those that can memorize facts and equations an understanding is completely irrelevant.     
Sounds like someone we all know here....     ::)
 

Offline electrodacus

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But keep in mind the main discussion here is about blackbird that is not allowed to travel at any angle other than direct down wind.

Hmmm.  Is that true for the propeller blades?  Are they going straight downwind?

Yes they are. You are just confused by that super bad example with the cylindrical earth.
Just think about the fact that propeller is fixed to the vehicle and propeller blades can only move around the shaft so when vehicle is at wind speed or above there is no air particle that is going to push against the propeller. The properer since it rotates will push some air back but that is not wind powering the vehicle.  Of course there is that pressure differential that you refuse to acknowledge and that will push the vehicle for some short amount of time.


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