LAMINAR-TRANSITIONAL-TURBULENT LIQUID FLOW IN SMOOTH CAPILLARY PIPES

Hydraulic characteristics smooth capillaries of 280.6 and 327.8 mu m in diameters in the range of]550, 6600[ (sic) Re were determined experimentally The critical Reynolds number Re-cr approximate to 2100 (concerns capillaries with sharp-edged inlets, since Re-cr increases, when the edge is rounded off), whereas the flow is turbulent, if Re >= 2800. The laminar-turbulent transition occurs in the range of]2100, 2800[ (sic) Re, and the characteristic curves cease to run unequivocally, however, they are contained in the area with it determined envelope (not given in the literature). It was confirmed, based oil 1420 author's results (6 capillaries 281-1270 mu m, Re is an element of]180, 58001), that the Hagen-Poiseuille law and the Blasius formula are also related to microscale flows.