  We perform the systematic numerical study of high vorticity structures that
develop in the 3D incompressible Euler equations from generic large-scale
initial conditions. We observe that a multitude of high vorticity structures
appear in the form of thin vorticity sheets (pancakes). Our analysis reveals
the self-similarity of the pancakes evolution, which is governed by two
different exponents $e^{-t/T_{\ell}}$ and $e^{t/T_{\omega}}$ describing
compression in the transverse direction and the vorticity growth respectively,
with the universal ratio $T_{\ell}/T_{\omega} \approx 2/3$. We relate
development of these structures to the gradual formation of the Kolmogorov
energy spectrum $E_{k}\propto\, k^{-5/3}$, which we observe in a fully inviscid
system. With the spectral analysis we demonstrate that the energy transfer to
small scales is performed through the pancake structures, which accumulate in
the Kolmogorov interval of scales and evolve according to the scaling law
$\omega_{\max} \propto \ell^{-2/3}$ for the local vorticity maximums
$\omega_{\max}$ and the transverse pancake scales $\ell$.
