Reynolds, Osborne

Rabi, Isidor Isaac, 253 Ramsay, William, 175 n.48 Ramus, Petrus, 60 Randall, Merle, 228 Raoult, Francis, 143-145, 146-147 Regnault, Victor, 52, 120 n.65 Remick, Edward, 221 Remsen, Ira, 113-114 Reynolds, Osborne, 177 Rice, Oscar K., 223, 254 Richards, Robert J., 15 Richards, Theodore William, 121 Rideal, Eric, 125... 

Reynolds, Osborne (1842-1912) published his famous paper that described the Reynolds number in 1883. The paper, An experimental investigation of the circumstances which determine whether motion of water shall be direct or sinuous and of the law of resistance in parallel channels, was published in the Philosophical Transactions of the Royal Society. 

Reynolds, Osborne. On the Theory of Lubrication and Its Application to Mr. BEAUCHAMP TOWER S Experiments, Including an Experimental determination of the Viscosity of Olive Oil. Phil. Trans. Roy. Soc. 1886, 177, 157-234 with one plate. 

Fluid-film bearings—Congresses. 2. Reynolds, Osborne, 1842-1912—Congresses. I. Dowson, D. 

The phenomenon of thermal transpiration was discovered by Osborne Reynolds [82], who gave a clear and detailed description of his experiments, together with a theoretical analysis, in a long memoir read before the Royal Society in February of 1879. He experimented with porous plates of stucco, ceramic and meerschaum and, in the absence of pressure gradients, found that gas passes through the plates from the colder to the hotter side. His experimental findings were summarized in the following "laws" of thermal transpiration. 

Reynolds Number. The Reynolds number, Ke, is named after Osborne Reynolds, who studied the flow of fluids, and in particular the transition from laminar to turbulent flow conditions. This transition was found to depend on flow velocity, viscosity, density, tube diameter, and tube length. Using a nondimensional group, defined as p NDJp, the transition from laminar to turbulent flow for any internal flow takes place at a value of approximately 2100. Hence, the dimensionless Reynolds number is commonly used to describe whether a flow is laminar or turbulent. Thus... 

Osborne Reynolds identified the phenomenon of cavitation as early as 1873. By the ton of the century it had been called by its present name by R. E. Froude, the director of the British Admiralty Ship Model Testing Laboratories. 

In the preceding categories of flow, the velocity field is deterministic since it can be calculated (at least in principle) from the constitutive equation of the fluid and the experimental boundary conditions. Turbulent flow, on the other hand, is distinctively unpredictable, as was pointed out a century ago by Osborne Reynolds. 

In 1883, Osborn Reynolds conducted a classical experiment, illustrated in Fig. 6-1, in which he measured the pressure drop as a function of flow rate for water in a tube. He found that at low flow rates the pressure drop was directly proportional to the flow rate, but as the flow rate was increased a point was reached where the relation was no longer linear and the noise or scatter in the data increased considerably. At still higher flow rates the data became more reproducible, but the relationship between pressure drop and flow rate became almost quadratic instead of linear. 

Measurements with different fluids, in pipes of various diameters, have shown that for Newtonian fluids the transition from laminar to turbulent flow takes place at a critical value of the quantity pudjp in which u is the volumetric average velocity of the fluid, dt is the internal diameter of the pipe, and p and p. are the fluid s density and viscosity respectively. This quantity is known as the Reynolds number Re after Osborne Reynolds who made his celebrated flow visualization experiments in 1883 ... 

A former student of Roscoe s, Schuster had been appointed to a new chair in applied mathematics at Manchester in 1881, following his studies at Heidelberg, Berlin, and the Cavendish Laboratory. One of his competitors for the position was J. J. Thomson, who had briefly been a student in engineering at Manchester under Osborne Reynolds. In his inaugural address, Schuster freely... 

In a turbulent flow field, equation (2.14) is difficult to apply because C,u,v, and w are all highly variable functions of time and space. Osborne Reynolds (1895) reduced the complexities of applying equation (2.14) to a turbulent flow by taking the temporal... 

An explosion or detonation produces both an air blast and a shock wave in the air. The air blast consists of the air in violent motion in a general direction away from the site of the expln and in a condition of extreme turbulence. This degree of turbulence may be imagined by estimating a "Reynolds Number of it, devised by Engl scientist Osborne Reynolds (1842-1912), to describe the effect of velocity phenomena in connection with flow of liquids. If k is Reynolds Number, d=diameter of moving stream, u = its linear velocity, p = its density and = its viscosity,... 

Now return to a view of the nature of flow in the boundary layer. It has been called laminar, and so it is for values of the Reynolds number below a critical value. But for years, beginning about the time of Osborne Reynolds experiments and revelations in the field of fluid flow, it has been known that the laminar property disappears, and the flow suddenly becomes turbulent, when the critical VUv is reached. Usually flow starts over a surface as laminar but after passing over a suitable length the boundary layer becomes turbulent, with a thin laminar sublayer thought to exist because of damping of normal turbulent components at the surface. See Fig. 6. 

REYNOLDS NUMBER. A dimensionless number that establishes the proportionality between fluid inertia and the sheer stress due to viscosity. The work of Osborne Reynolds has shown that the flow profile of fluid in a closed conduit depends upon the conduit diameter, the density and viscosity of the flowing fluid, and the flow velocity. 

Over 100 years ago, British physicist Osborne Reynolds discovered that the flow of a fluid through a conduit becomes turbulent when the momentum of the fluid exceeds its resistance to flow by a factor of 2000-3000 (Reynolds, 1883). The ratio of these opposing forces, known as the Reynolds number (Re), is expressed as... 

In order to calculate / certain dynamic forces of mass flow must first be determined. Knowing these forces resisting flow are along the pipe wall, the work of Osborne Reynolds has shown that certain fluid transport properties compose this friction force. Reynolds proved with... 

Considering the ratio of inertia forces to friction forces, a parameter is obtained called the Reynolds number, or Reynolds law, in honor of Osborne Reynolds, who presented it in a publication of his experimental work in 1882. However, it was Lord Rayleigh 10 years later who developed the theory of dynamic similarity. 

In polymer processing, we frequently encounter creeping viscous flow in slowly tapering, relatively narrow, gaps as did the ancient Egyptians so depicted in Fig. 2.5. These flows are usually solved by the well-known lubrication approximation, which originates with the famous work by Osborne Reynolds, in which he laid the foundations of hydrodynamic lubrication.14 The theoretical analysis of lubrication deals with the hydrodynamic behavior of thin films from a fraction of a mil (10 in) to a few mils thick. High pressures of the... 

Osborne Reynolds was the first to show that tightly packed granular solids expand their volume when deformed.84 This phenomenon is called dilatancy. It is well understood and is discussed in some detail in the literature on soil mechanics.85-87 In vitreous-bonded structural materials such as silicon nitride, dilatancy has been suggested as a contributing factor in the formation of cavities,88 and may be an important factor in the cavitation of ceramic matrix composites.64 Dilatancy has also been suggested as an important factor in controlling the creep and creep relaxation of glass-ceramics.89... 

After Navier- Stokes equation has been written down in the first half of nineteenth century, few exact solutions were obtained for few fluid flows. In one such case, Stokes compared theoretical prediction with available experimental data for pipe flow and found no agreement whatsoever. Now we know that the theoretical solution of Stokes corresponded to undisturbed laminar flow, while the experimental data given to him corresponded to a turbulent flow. This problem was seized upon by Osborne Reynolds, who explained the reason for such mismatches by his famous pipe flow experiments (Reynolds, 1883). It was shown that the basic flow obtained as a... 

Equation 9.11 is usually referred to as Poiseuille s law and sometimes as the Hagen-Poiseuille law. It assumes that the fluid in the cylinder moves in layers, or laminae, with each layer gliding over the adjacent one (Fig. 9-14). Such laminar movement occurs only if the flow is slow enough to meet a criterion deduced by Osborne Reynolds in 1883. Specifically, the Reynolds number Re, which equals vd/v (Eq. 7.19), must be less than 2000 (the mean velocity of fluid movement v equals JV, d is the cylinder diameter, and v is the kinematic viscosity). Otherwise, a transition to turbulent flow occurs, and Equation 9.11 is no longer valid. Due to frictional interactions, the fluid in Poiseuille (laminar) flow is stationary at the wall of the cylinder (Fig. 9-14). The speed of solution flow increases in a parabolic fashion to a maximum value in the center of the tube, where it is twice the average speed, Jv. Thus the flows in Equation 9.11 are actually the mean flows averaged over the entire cross section of cylinders of radius r (Fig. 9-14). 

Vol. 11 Fluid Film Lubrication - Osborne Reynolds Centenary (Dowson et al.. Editors)... 

It is possible to convert one method of description to the other using the Reynolds transport theorem attributed to Osborne Reynolds. In other words, the theorem converts the Eulerian method of description of fluid flow to the Lagrangian method of description of fluid flow and vice versa. 

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