Quote:
Originally Posted by Cd
Even if you create a tail that is not ' ideal ' in length, you are still filling in a large portion of you wake...right ?
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Hi Cd,
You are absolutely correct. The entire object of creating a boat-tail is to reduce the amount of turbulence at the back of the object moving through the air.
One way to do that is to add a 'tail' and taper it to allow the air to stay attached as far back as possible. The farther the air stays attached, the smaller the overall wake size with be, and this in turn lowers the overall drag.
And the angle of taper is important as well. Obviously we want to use a steep angle so that skin friction is low, but at the same time, if the angle is too steep, then the air will detach before the end of the tail, and create a larger hole in the air stream.
So there is a balance between choosing a steep angle of taper (loss of attachment), and using a slight angle and making the tail too long (increased skin friction).
Jim.