SIMILARITY SOLUTIONS OFVISCOUS FLOWS IN THESECTION-GRADUALLY-VARYINGPIPES

Similarities of axisymmetrical internalfluid flows are discussed in this paper. Similarity so-lutions exist only for a special kind of tube shapes.In this case, a pressure formula may be derived andvelocity and local friction coefficient distributionsmay be computed numerically. The results showthat the Hagen-Poiseuille flow in strait pipes is alimit state of our cases.