Erratum to: Viscous flows with flat free boundaries

1 Erratum to: Eur. Phys. J. Plus (2020) 135:554 https://doi.org/10.1140/epjp/s13360-020-00552-z

The original version of this article contains a mistake.

The correct form of the equation (11) is:

$$\begin{aligned} \frac{\mathrm{d}^{3}\psi }{\mathrm{d}\xi ^{3}}+\left( \frac{\xi }{2}-\psi \right) \frac{\mathrm{d}^{2}\psi }{\mathrm{d}\xi ^{2}}+\left( \frac{\mathrm{d}\psi }{\mathrm{d}\xi }\right) ^{2}+\frac{\mathrm{d}\psi }{\mathrm{d}\xi }=0. \end{aligned}$$

The graph of function $\psi (\xi )$ shown in Figure 2 is based on the correct equation.