  We discuss a simple analytical model of the turbulent boundary layer (TBL)
over flat plane. The model offers an analytical description of the profiles of
mean velocity and turbulent activity in the entire boundary region, from the
viscous sub-layer, through the buffer layer further into the log-law turbulent
region. In contrast to various existing interpolation formulas the model allows
one to generalize the description of simple TBL of a Newtonian fluid for more
complicated flows of turbulent suspensions laden with heavy particles, bubbles,
long-chain polymers, to include the gravity acceleration, etc.
