Concept explainers
A popular gravity-driven instrument is the Cannon-Ubbelohde viscometer, shown in Fig. C1.10. The test liquid is drawn up above the bulb on the right side and allowed to drain by gravity through the capillary tube below the bulb. The time t for the meniscus to pass from upper to lower timing marks is recorded. The kinematic viscosity is computed by the simple formula: v = Ct where C is a calibration constant. For v in the range of 10U-50U mm2/s, the recommended constant is C = 0.50 mm2/s2, with an accuracy less than 0.5 percent.
(a) What liquids from Table A.3 arc in this viscosity range? (b) Is the calibration formula dimensionally consistent? (c) What system properties might the constant C depend upon? (d) What problem in this chapter hints at a formula for estimating the viscosity?
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FLUID MECHANICS W/ CONNECT
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