IV. Determination of the viscosity of water

Abstract

material, and the potassium chloride formed exercises its specific influence on this reaction.The secondary action upon potassium iodide producing iodine is practically an instantaneous one, unless the quantity of this substance is below a certain minimum. Below this the velocity observed in the mixture will be less than normal. The effect of increasing the amount of this substance to much greater than the minimum is closely analo gous to that of a similar increase of any neutral salt.The velocity is an exponential function of the temperature, as was observed in Messrs. Harcourt and Esson's investigations. As the latter increases in arithmetical progression, the former increases in geometrical progression. The rate is about doubled for a rise of 5° 0. The ratio in this progression is not, however, absolutely constant, but varies a little with the temperature at which it is taken. Thus between 0° and 15° C. the rate is a little more than doubled for a rise of 5° ; between 20° and 30° it is a little less than doubled. Communicated by Lord R a y l e i g h , Sec. R.S. Received November 30, 1888.The experiments here described, which were made during April and May of the present year (1888), to determine the constant of viscosity of water, may be of some interest on account of the newness of the method employed, and also as being on rather a larger scale than other experiments which have been made with the same object. Fig. 1 gives a section of the apparatus used. A and B are two coaxial cylinders; of these A is mounted on the vertical axis E, and can be made to rotate by a belt passing over the wheel F. B is suspended by a long fine wire C, and the annular space between A and B is filled with water or any other fluid to be experi mented on.A little way above the lower edge of B is fixed an air-tight dia phragm D, so that when the space between the two cylinders is filled with liquid air is inclosed under D, and the liquid touches B only on the cylindrical surface.The interior of B above D is filled with water which serves the purposes of checking the torsional vibrations of B, of preventing any rapid change of temperature of the liquid in the annulus, and of holding the thermometer.The experiments were made by driving the cylinder A at a uniform speed and recording the angle through which B is turned when it comes to rest under the action of the fluid friction on its cylindrical surface and the torsion of the suspending wire C. A was driven by 1888.]

Theoretical Analyses of the Number of Backflow Vortices on an Axial Pump or Compressor

“…Couette flow is shear flow in the space between two surfaces with different speeds. Mallock [1,2] in 1889 and 1896 and Couette [3] in 1890 independently conducted similar experiments in which they used two coaxial cylinders mounted on a vertical axis rotated at different rotational speeds. The annular space between the cylinders was filled with water, mercury, or air.…”

The measurement of constrained elastic recovery in polymeric solutions

“…Its shape was such that when the liquid was pumped into the apparatus through the filling tube E and up the tube F air was trapped in the chamber D. On rotating the outer cylinder, the liquid was sheared only between the cylinder walls and not between the bottom of the outer cylinder and the inner cylinder, of. Malloclc (24). The inner cylinder was constructed with a removable shelf G upon which could be placed the slotted discs H so that the effect of varying the moment of inertia of the inner cylinder assembly could be investigated.…”

Taylor–Couette flow of hard-sphere suspensions: overview of current understanding

“…It is considered a paradigm for hydrodynamic stability and transition studies. Since the original experiments of Mallock [13] and Couette [14] and the seminal analysis and experiments of Taylor [15], the flow transitions of a Newtonian fluid in the Taylor-Couette geometry have been extensively studied in various experimental, theoretical and numerical works [11,12,[16][17][18][19][20][21][22]. At low rotation rates of the cylinders the realized flow is the circular Couette flow (CCF), which is unidirectional in the azimuthal direction and only has radial dependence.…”