If you mean that you need to determine what type you need to suit a particular application, you can probably best determine it by comparing fan or propellor properties from aerodynamics. A windmill is just a fan in reverse. For instance, large highly angled blades (paddles) will give more torque at lower speed which is what the Dutch style requires to run heavy mechanical equipment. Smaller, flatter, more numerous ones (turbines) give high speed with little torque, as you find running alternators on some farms. There are also vertical turbines such as are used on some 'wind farms'. They are more like helicopter rotors set on end. Medium speed and torque, but very high efficiency. Height above the ground and placement relative to other physical objects also matter, because it should be in the highest average airflow.brucephy said:i know there are so many types of windmill
and they all have their specific advantages and suitable application.
But i cant find the detail about that. )o(
can anyone help me ??
quark said:The flowrate across a fan depends upon the fan speed and the primemover should have enough power to move the air. You can use affinity laws of fan.
Q1/Q2 = N1/N2, H1/H2 = (N1/N2)^2 and P1/P2 = (N1/N2)^3, where Q is flowrate, H is head developed and P is power. When flowrate is high, the primemover develops power till it gets overloaded and trips off.
The above link provides you basic and detailed knowledge on fans.