Drag coefficient Hadamard

One of the earliest works on the flow past a slightly deforming viscous drop in a flow with a large density ratio is that of Hadamard [7], which considers Stokes flows. They offered the following expression for the drag coefficient ... 

In a more recent study, which is an extension of the previous works, Saboni et al. [15] proposed a predictive equation for drag coefficients covering Reynolds numbers in the range 0.01 < Re < 400 and viscosity ratio from 0 to 1000. This correlation, which is reduced to the solution of Hadamard [4] and Rybczynski [5] for Re 0, is as follows ... 

Although small drops behave like rigid spheres, this similarity of behaviour does not extend beyond a Reynolds number of around 10. For larger drops internal circulation of the Hadamard-Rybczynski type sets in which reduces the drag coefficient to a value below that of a corresponding solid sphere. However, larger drops are also subject to deformation, the extent of which depends on the Weber number (8)... 

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