Re: Buddy golf balls

Michael Bell wrote:
One would have thought that perfectly smooth objects would go most easily through the air, but golf balls have dimples because, so golfers tell us, they fly better like that. Since golf is a rich man's game and testing is easy, we've got to take that as true.

Presumably golf balls have dimples rather than grooves because golf balls turn in the air and they don't know which way the air is going to come from, so round dimples will take the air from any direction.

That brings to mind the corrugations of American Budd railcars. I am sure they were built like that for styling or structural reasons, but it does make you wonder whether there might be an aerodynamic reason? In the case of a railway vehicle you know which way the air is coming from and it would be difficult to build railway vehicles with dimples to the same depth in proportion to the vehicle's size - milled aluminium plating maybe? - but there is no difficulty about corrugated ***. But which way should they lie? Along or across?

The simple answer is no, the ribbing will not be for aerodynamic reasons, and it is unlikely to have any beneficial effect. The longer answer is the issue of dimples is to do with boundary layer separation, and along the (otherwise smooth) side of a railway vehicle there should be no separation with or without surface features of this kind. The sides (and top and bottom) of a railway carriage really just want to be as smooth as possible.

Robin
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