Managing Model Tolerances

Using C1 continuity, points out this article, is attractive to CAD modelers since it “is a much lighter data representation and yet still looks very pleasing to the eye“. CFD, in many cases, requires much more precision than that, given first-cell spacings of the order of 1 micron are not uncommon. There’s no easy way out but there are some approaches that are better than others. A common trap: when a CAD application outputs an IGES file the results are almost always sub-standard.