Dynamic scaling length

If the crossover points Q (x) are determined from Fig. 45, taking the x-values at half-step height, Q (x) = 1/1 (x) = (0.7 + 0.2)x is obtained in the case of the PS system. This has to be compared with static value Qs (x) = 1.6x, derived from the same polymer solvent system by elastic neutron scattering [103], As long as no corresponding data from other polymer solvent systems are available, the final decision as to whether static and dynamic scaling lengths coincide or not, is still open. 

There is a time-honored description of the mutual diffusion coefficient in terms of a dynamic scaling length f, namely... 

This also is refetTed to as the Reynolds criterion. Reynolds numbers are only comparable when they refer to geometrically similar flows and. provided that all the boundary conditions can be described by the scale velocity and scale length, flows of the same Reynolds number are dynamically similar. For an airfoil, it is... 

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