Windmills..Backyard type...which way do they point

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You have all seen those backyard windmills, about 4-6 high that turn in the wind? I never paid much attention as to how they worked until I purchased and assembled a used one for my 85 year old mom. The windmill fan blade will turn and the whole tops pivots based on the wind direction. But which way? For example, lets says the wind is coming from the North. Do the rotating fans blades turn into the wind, so they would face North, or are the pushed to the South? I thought maybe the direction of the blades might make a difference, but I think the direction of the blades only changes which way the fan blade rotates? Anyone actually know?
 
Originally Posted By: tgrudzin
You have all seen those backyard windmills, about 4-6 high that turn in the wind? I never paid much attention as to how they worked until I purchased and assembled a used one for my 85 year old mom. The windmill fan blade will turn and the whole tops pivots based on the wind direction. But which way? For example, lets says the wind is coming from the North. Do the rotating fans blades turn into the wind, so they would face North, or are the pushed to the South? I thought maybe the direction of the blades might make a difference, but I think the direction of the blades only changes which way the fan blade rotates? Anyone actually know?


If its a scaled-down model of a classic ranch/farm type windmill, he tail vane of the windmill is what aims it into the wind. The tail vane is usually behind the "turbine" so that the blades aren't shadowed by the tower, in other words it rotates the turbine face-on into the wind. In the picture below, the wind would be coming from the right toward the left:

Windmill_4_Large.jpg


In a full-scale windmill, the tail is hinged and a lever at ground level lets the operator flip it so that it drives the blades side-on to the wind so that the windmill will not rotate (a band brake is also applied). Further, the tail vane is offset and spring-loaded so that in very high winds, it will start to slew the turbine wheel sideways and out of the direct wind as a sort of crude governor or self-protection. The image below shows a windmill that has been shut down by manually flipping the tail vane sideways to the rotor:

an-old-style-windmill-built-by-the-aermotor-company-of-chicago-aa7yw9.jpg
 
Originally Posted By: HosteenJorje
Hard to understand how anyone could be confused as to how this device works.


Yes - by simple observing it on a windy day, on can deduce it's operating parameters.

BTW, it doesn't matter which direction the wheel rotates (CW or CCW)
 
Originally Posted By: HosteenJorje
Hard to understand how anyone could be confused as to how this device works.


My wife does - if I say there is a northerly wind, she asks if the wind is coming from the north, or going to the north. When she asks why, I say just because. Do you face into the wind, or put your back to the wind...I guess that's the way she sees it.
 
Originally Posted By: Silk


My wife does - if I say there is a northerly wind, she asks if the wind is coming from the north, or going to the north. When she asks why, I say just because. Do you face into the wind, or put your back to the wind...I guess that's the way she sees it.


I actually understand that one because its backwards to how everything else works.

A north wind is from the north

While anyone traveling north is going in the opposite direction.


A windmill in normal operation on the other hand, the tail(vane) is always going to be behind the blades.. just because of how it works to steer it into the wind.
 
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