  Past numerical simulations and experiments of turbulence exhibit a hump in
the inertial range, called the bottleneck effect. In this paper we show that
sufficiently large inertial range (four decades) is required for an effective
energy cascade. We propose that the bottleneck effect is due to the
insufficient inertial range available in the reported simulations and
experiments. To facilitate the turbulent energy transfer, the spectrum near
Kolmogorov's dissipation wavenumber has a hump.
