Quote:
Originally Posted by Varn
That is a great way to look at the shape. It is nearly spherical.
Do you think that if the front is not as good as the ideal image that we might need to be more conservative and use a 6 or 7 d shape?
I am thinking of my 86 jetta with it basically being a box with very little radii on the front.
Did I miss you tuft testing your tailbox?
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All my texts recommend a nose based on a convex hemisphere for sub-transonic flow.When we consider the 115-degrees of radius rule for the point of turbulent boundary layer separation,the convex hemisphere is the only shape which best satisfies that condition for crosswinds.
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With respect to the Jetta,Hucho was personally involved with streamlining of the 1st-gen Golf/Jetta.You can see smoke flow images of their noses in the 'Flow-Images' thread.While I would say that the plan-view rounded nose has an advantage in crosswind,Hucho has said that it's attached flow leads us to go straight to the rear as JethroBodine has done.
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If we go' longer' than the 'Template',it's okay in that there won't be flow separation,but the structure will be weaker structurally as we move away from the 'tighter' ovoid form,and it will of course be heavier,which won't really show on the highway,but would impact urban driving mpg.
Each of us must weigh out their specific needs and mod accordingly.Nothing's set in cement.
