OT:- Faster than the speed of wind.

[Demon69]

Doesnt seem like it should work, but

Enjoy

 

[Scruffy887]

Ever break wind sitting in your vehicle with the air conditioned seat blower on? That goes blazing fast.

 

[Bill D]

I always heard that on a dead calm day if a sail boat is drifting downriver. once it gets enough speed 3-5 mph it can raise the sails and it's speed will increase.
Turbine attic ventilators will exhaust more air then a equal size open hole. On a dead calm day they will start to spin as the air heats up inside and rises. As they start to spin faster they pump more air and the rpm will increase as will airflow. Of course any slight breeze will start them spinning even if the delta T is not enough for a static start.
Anyone want to chime in about the sailboat with spinning vertical cylinders for sails? The America's cup boats use ridgid airfoils longer then any jumbo jet wing.
Bill D

 

[Forestgnome]

I've seen a lot of these videos, and don't believe it works the way they say it does. Otherwise it would be a perpetual motion machine, which can't exist. The models tha work on the treadmill work because there's no forward wind speed to negate the thrust from the propeller. If this works the way they say it does, you could push the machine up to a certain speed on a windless day and it would take off on it's own. I want to see that.

 

[Demon69]

Heres some more, a bet was won.

 

[Garwood]

I've seen a lot of these videos, and don't believe it works the way they say it does. Otherwise it would be a perpetual motion machine, which can't exist. The models tha work on the treadmill work because there's no forward wind speed to negate the thrust from the propeller. If this works the way they say it does, you could push the machine up to a certain speed on a windless day and it would take off on it's own. I want to see that.

It's not a perpetual motion machine and NO, it would not work if there was no wind. Go back and watch it again if you don't grasp it.

It makes complete sense to me.

At first it didn't because they keep you in the dark about what the propeller is doing. They kinda lead you to believe the propeller is powering the wheels.

 

[sealark37]

The controlling proven process is Bernoulli's Theory.

 

[Forestgnome]

It's not a perpetual motion machine and NO, it would not work if there was no wind. Go back and watch it again if you don't grasp it.

It makes complete sense to me.

At first it didn't because they keep you in the dark about what the propeller is doing. They kinda lead you to believe the propeller is powering the wheels.

Faster than the wind would be the same as pushing it forward to start it running. Moving forward at 15mph with a 10mph tailwind is exactly the same as moving 5mph with no wind.

 

[Garwood]

Faster than the wind would be the same as pushing it forward to start it running. Moving forward at 15mph with a 10mph tailwind is exactly the same as moving 5mph with no wind.

It isn't the same at all.

I'm not going to go through the effort to make a detailed video explaining exactly how it works and why you are wrong, but luckily, some people already did.

 

[mhajicek]

I've seen a lot of these videos, and don't believe it works the way they say it does. Otherwise it would be a perpetual motion machine, which can't exist.

This works by extracting energy from the difference between the windspeed and the groundspeed. Here's a purely mechanical demo, substituting a board for the wind:

https://youtu.be/yCsgoLc_fzI?t=852

 

[Rickyb]

Just another perpetual motion machine.

 

[Milacron]

Closed due to meaningless topic title

 

[mhajicek]