Laboratory Notes by Professor Tait 2. On the Flow of Water through Fine Tubes

Extract

Dr Matthews Duncan recently asked me whether the flow of blood under given pressure would be affected by a considerable change of form of the section of a small vein or artery. It appeared obvious, from the well-known experiments of Poiseuille (which show that when the bore of a capillary tube of circular section is sufficiently small, the flow through it is as the fourth power of the diameter), that the flow through a capillary tube of elliptical section must be le^s than that through a circular tube of equal sectional area.