Bringing wind energy to the ground through a giant pitot tube

[steamdreamer]

Ok not a great title, but let me try to explain the idea.
Imagine that you have say a parachute attached to the top of a flag pole. In the center of the parachute a hole is cut and connected to a plastic tube that goes to the ground. When the wind comes up the parachute exerts a drag on the air and this tube connects the low pressure backside of chute to the ground. At the ground level inside the tube is a turbine that will spin as a result of the suction created. To enhance the energy transfer there will be a tube concentrically centered around the low pressure tube that transmits the high pressure air to the underside of the turbine on the ground. Essentially its a giant pitot tube with the parachute acting as a flow obstructor, the two line then transmit differential pressure to the ground. So would it an effective way to transfer wind energy?

The pros would be that you could bring all maintenance to a ground level, and eliminate gigantic tower weights and costs.

I am not certain how to proced modeling or thinking numerically about such an idea. Any ideas?

 

[phyRob]

I can't quite visualize this. I don't see where the low pressure is.

The pros would be that you could bring all maintenance to a ground level, and eliminate gigantic tower weights and costs.

You still need a tower for the parachute, and a plastic tube and a fragile parachute which will need to be repaired. The tube needs to be fairly large because the turbine won't spin unless there is a lot of air moving through it.

 

[steamdreamer]

I've attached a very poor sketch of what I'm thinking. The low pressure region should be behind the parachute since it is blocked off from wind flow.

 

[russ_watters]

There isn't much pressure behind the wind so there would be an awful lot of loss.

 

[AlephZero]

Ignoring the practical details of building it, a basic problem with your thinking is that there is no "pressure drop" behind the HOLE in the parachute where your tube is.

Yes there is a pressure difference between the front and back of the rest of the chute, but even that is a very small pressure. Think about the size of an "old style" circular parachute that is needed to support a 200lb person doing a parachute jump. The pressure difference across the chute is probably less than 1 psi. That is not enough to generate an useful amount of energy.