461. 回転円筒の風損

抄録

An empirical relationship for the windage losses of a rotating inner cylinder in a concentric stationary outer cylinder was obtained as a function of the rotaing speed of the inner cylinder and the gap width between both cylinders, through analysis of theories by Taylor, Davey and Batchelor, and experiments by Wendt, Taylor and Donnelly. lnformation was also gained on the critical speed at which instability sets in, which depends on the gap width. The formula relating the friction factor f to rotating Reynolds number Red^*, and to the ratio between gap width and radius d^* can be applied to a range of Red^* values from the critical value to about 200 times thereof and to a range of d^* from 0 to 1, within an error of 30%.
Measurements of the windage loss of a Zippe-type gas centrifuge 34.9cm long with a radius of 5.20cm have been made for three mantle inner radii of 6.30, 7.04 and 8.20cm.
Experimental results plotted in f vs. Red^* with d^* as parameter agree well with the curves calculated by the present formula.