  In this work, we simulate the transition to turbulence in the pipe flow based
on the modified NS theory incorporating the viscous fluid strength in the
constitutive equations. The latter concept enriches theory by allowing for
material instabilities in addition to the kinematic ones. We present results of
comparative numerical simulations based on the classical NS model and the NS
model enhanced with the finite viscous strength. As expected, simulations based
on the classical NS model exhibit stable laminar flow in contrast to
experimental observations. Conversely, simulations based on the modified NS
model with viscous strength exhibit instabilities and transition to turbulence
per experimental observations. The transition to turbulence is triggered by the
growing material instabilities.
