Curvature correction factor

Although the Rockwell test is intended to be used on flat parallel-sided specimens, its use can be extended to rounded surfaces by using a curvature correction factor. Compound surfaces such as gear teeth can be tested but the results must be corrected for curvature. 

Fig. 9.8 Curvature correction factor for drag flow for a Power Law model fluid. /v,. fl 0 denotes the ratio of drag flow between parallel plates to drag (Couette) flow between concentric cylinders at equal gaps and moving surface velocities. The subscript 6 — 0 indicates that in screw extrusion this correction factor is rigorously valid only in the limit of a zero helix angle. [Reprinted by permission from Z. Tadmor and I. Klein, Engineering Principles of Plasticating Extrusion, Van Nostrand Reinhold, New York, 1970.]...

The curvature correction factor in parentheses in (11-29) is calculated explicitly for creeping flow of an incompressible Newtonian fluid around a solid sphere, where... 

Now, it is possible to predict the curvature correction factor F r]) for the radial term in the equation of continuity at any position in the fluid (see Table 11-1) ... 

TABLE 11-1 Exact Calculations of the Curvature Correction Factor and the Error Embedded in the Radial Term of the Locally Flat Equation of Continuity"... 

Hence, neglecting the curvature correction factors of in the radial term of the equation of continuity corresponds to a 14% underestimate of (l/r )[d(r Vr)/dr] at the outer edge of the mass transfer boundary layer on the equator of the pellet. 

The curvature correction factor g is dimensionless, as are the solvation constants K, andK. The parameter gA is expressed in molecule by giving the surface tension the units J (where 1 erg em = 1 x 10 J... 

The reduced reliability index is thus dependent on the mean renewal rate of the process approximating the traffic load, on the curvature correction factor and time correction factor. 

Ineq. [5.5.14] g is a curvature correction factor, an empirical quantity that corrects the conventional surface tension y for the curvature of the cavity needed to contain a solute molecule. A is the surface area of this cavity in molecule" in Sections 5.5.3 and 5.5.4 we treat the meaning of A in more detail, but here we only make the assiunption that it is essentially eonstant, that is, independent of Xj. 

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