On the Conditions at the Boundary of a Fluid in Turbulent Motion . n the surface friction in the 0*714 cm. pipe is 10 dynes per square centi-metre, the value of dVfdr at 0*075 mm. from the wall would be 57,200 if theflow were streamline in character. The measured value of dY/dr was33,600. In the case of the 5-inch pipe, the corresponding values are 211,200for streamline motion and actually observed. - (2) The speeds calculated from the observations at distances of 0*075 less from the walls are appreciably higher than would exist in laminarflow with the measured surface friction.
On the Conditions at the Boundary of a Fluid in Turbulent Motion . n the surface friction in the 0*714 cm. pipe is 10 dynes per square centi-metre, the value of dVfdr at 0*075 mm. from the wall would be 57,200 if theflow were streamline in character. The measured value of dY/dr was33,600. In the case of the 5-inch pipe, the corresponding values are 211,200for streamline motion and actually observed. - (2) The speeds calculated from the observations at distances of 0*075 less from the walls are appreciably higher than would exist in laminarflow with the measured surface friction. For example, in the 0-714 cm. pipe,with a frictional resistance of 10 dynes per square centimetre, the calculatedspeed at 0*075 mm. from the walls was 795 cm. per second. In laminar flowwith this value of the surface friction the speed would be 443 cm. persecond. In the case of the 5-inch pipe at a value of the surface friction of36*1 dynes per square centimetre, and at a distance of 0*5 mm. from the Conditions at the Boundary of a Fluid in Turbulent Motion, 421. *03S jad suo \M Fi^^iDOi^ 422 Mr. T. E. Stanton and others. On the wall, the corresponding values are 1230 for the calculated speed and 1050for the speed in streamline flow. To sum up the evidence afforded by the curves of figs. 3 and 5, it wouldappear that if it may be assumed that the speed indicated by the Pitot tubeis the speed of the fluid at its geometrical centre during the experiment,streamline motion if it exists must be confined to a region of less than0*05 mm. from the boundary, and further, the observations are not inconsistentwith a finite amount of slip at the boundary. It was evident, therefore, that the proof of the existence or otherwise ofstreamline motion at the boundary would involve a closer exploration of theregion near the boundary than had hitherto been possible. This, however,could not be done with the available appliances owing to the fact that anyfurther reduction in the cross dimensions of t
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectproceed, bookyear1920
