Turbocharged engines exhibit the so called turbo lag phenomenon causing a disadvantageous
response comparing to atmospheric or mechanically supercharged engines. There are
many solutions developed to reduce the lag effect although each of them has some disadvantages.
This paper investigates a booster module that injects compressed air to increase the
response of turbocharged compression ignition engines of commercial vehicles. The
investigations applied 3D computational fluid dynamic (CFD) simulations in stationary
and transient manner as well. The transient simulations were applied as standalone
and coupled calculations to a 1D engine simulation code to capture more accurate boundary
conditions (BC). The drawbacks and problems of this new and advanced approach are
emphasized in the paper. Due to the deformation of the flow field boundary surface
during the dynamic process a deforming mesh method has been applied here. Instant
shape of flow field boundary has been obtained by solving the equation of motion of
the actuator rotor. By applying the above methods it was possible to validate the
booster module design variants and to identify the main characteristics of the complete
system including the engine.