kkk turbos , VATN

[mrukir <mrukir@snet.net>]

Hello:
    Here is my 2 cents worth on the turbo discussion.  I beleive the
variable intake guide vanes allow a smaller turbo to adapt to changing
operating conditions. The small turbo allows fast spool up because of
its low mass and lower inertia.  As the mass of air that the impeller is
pumping increases, there are efficiency gains to be had by changing the
angle of attack of the incoming air on the vanes of the impeller.  In
other words the smaller turbo can acheive some of the performance of a
larger turbo by changing the inlet guide vane angle.
     Jet engines which are really just very big turbo chargers with
their own internal fuel combustor employ this same operating feature.
The changing angle of the guide vanes actually acts as a variable sized
nozzle so that the flow area as well as the angle of impingement is
varied to optimize performance.
    This is a very complex subject and I'm sure my understanding of it
is only partially accurate, but I think some of the essentials are
there.
                                       Paul Balko