Thanks everyone. The discussion is leading to better definition of the problem or issue, I think.
ione the question i am asking is why is the efficiency so different between water and air. To continue with your equations:
F exerted on water turbine = 2*rho*Q*?V
Power delivered to turbine =...
Cup anemometer is very inefficient--very small volume of air is used to perform work. That is why it is not used for capturing energy; it is used for measurement.
Another way to ask the question is: If we were to design a mechanism to funnel the air from the entire rotor diameter into a focused pipe and use pelton wheel like device to impart energy from air, would the efficiency be higher than using aerodynamic blades?
About the previous post, I think...
In a water turbine most (90%-plus) of the kinetic energy contained in a water jet is converted into rotational energy of the turbine. Example, a pelton wheel water turbine that is a cup that turns around a water stream 180 degrees yields very high efficiency because all the momentum change can...
Want to clarify my post. Suppose the cylinder is 50cm long and 5cm in diameter and it is put into the ground (like a foundation) vertically. So one end of the bolt is at the 50cm below the ground and other end of the bolt is sticking out. Bolt is post-tensioned with 10N.
In this scenario...
I am trying to understand the basic physics of post-tensioning. Consider the following:
Concrete hollow cylinder, say 5cm in diameter has a hole of diameter 1cm. Put a steel bolt of dia 0.75cm, put a nut at the bottom and top; post-tension it to 10Newtons. I stick this in the ground. Assume...
