A flow conditioner includes a body composed of an array of vanes generally parallel to the direction of fluid flow. The vanes create a plurality of chambers to effectively reduce large scale vortices in the flow. The vanes have surfaces with perforations to allow pressure regulation between chambers to effectively reduce asymmetric flow and reduce drag. Additional preferred features include an acoustic choke created by a reduction in cross-sectional flow area at the entrance and the exit of the flow conditioner with circular plates. The plates have rough edges to increase production of micro-vortices.
