Local radial velocity gradient

A velocity profile u(r) is obtained using MRI flow imaging and, with respect to radial position r, the values of shear rate y(r), ranging from zero at the tube center to a maximum at the tube wall, can be calculated from the velocity profile as local velocity gradients ... 

This term may be determined in various ways from experimental data. A frequently used method for single-phase flow (S4) is to differentiate an experimental velocity profile graphically, and to obtain the kinematic viscosity from the velocity gradient with basic relations [e.g., Eqs. (3-1) and (3-2)]. The currently available data for velocity profile do not appear accurate enough to yield as a function of radial position. As an alternative, Hills (H9) has assumed a relation between the local vt and the radial position ... 

Radial dispersion of heat In wall-cooled or heated reactors, the heat release or consumption leads to radial temperature gradients. Even for an adiabatic reactor such gradients may occur because of local radial differences of the fluid velocity... 

Let the magnetic field with the value of intensity gradient V// be localized in the area of I size within the vessel of d diameter (Figure 10.1). In the Poiseuille (parabolic) approximation the velocity distribution in cross-section of the vessel taken as a circular cylindrical tube, there is the following velocity distribution law on radial coordinate r ... 

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