What is the direction of the wind based on flag direction

[TheWonderer1]

I think it is about 90 degrees off but I never thought about wind direction too much. I guess let's say the wind is coming from the NE and there is nothing behind the flag so it's on a field. I know a windcone is 180 degrees so opposite wind direction.

 

[Orodruin]

Why do you think a flag would be any different froma windcone? And if it was not 180 degrees off, which of the two directions would it go?

 

[A.T.]

I think it is about 90 degrees off...

How about directly upwind, like on many sail ship paintings?

 

[CWatters]

LOL

Fortunately not all paintings are wrong.

https://goo.gl/images/rK1zoi

 

[Ibix]

Getting a small flag and blowing on it is also a fairly simple experiment, if you've any doubts.

 

[TheWonderer1]

I figured out soon after writing it. It should be 180 degrees and found that this is true in practice.

 

[boneh3ad]

How about directly upwind, like on many sail ship paintings?

To be fair, sailing ships aren't necessarily pointed directly downwind ( and in fact perform better when they aren't. They can even almost sail into the wind, called tacking. So the picture isn't really impossible by any stretch.

 

[A.T.]

To be fair, sailing ships aren't necessarily pointed directly downwind ( and in fact perform better when they aren't. They can even almost sail into the wind, called tacking. So the picture isn't really impossible by any stretch.

That picture is. Note the sails.

 

[davenn]

That picture is. Note the sails.

filling in different directions LOL

 

[Orodruin]

filling in different directions LOL

There could be a strong velocity gradient ...

 

[Vanadium 50]

Note the sails.

I wonder if they are using the same wind we are using.

 

[Ibix]

Maybe the painter was three sheets to the wind ?

 

[Orodruin]

Also, I must say that it is not completely clear to me that the flag is flying towards the stern and the sails could very well be at an angle to the ship that is not 90 degrees. Compare to this:

 

[A.T.]

Also, I must say that it is not completely clear to me that the flag is flying towards the stern and the sails could very well be at an angle to the ship that is not 90 degrees. Compare to this:
View attachment 203255

That's a different type of sails. What you mean would look like this on the pirate ship above:

But this is not how that sails are set on the pirate ship image (which was just an example for an error you sometimes see, maybe not the clearest one).

 

[TheWonderer1]

Eh, is the suggestion here that on a sail boat it would be different? Went away for a while but in fact, that's why I asked.

 

[A.T.]

Eh, is the suggestion here that on a sail boat it would be different? Went away for a while but in fact, that's why I asked.

On a sail boat the flag orients down the apparent wind. At the height of the sails (like the big US one above) it's affected by the airflow diverted by the sails.