cfd investigation of turbocharger ported shroud compressor

Compressor covers with ported shrouds are used to recirculate low momentum air near the tips of the inducer blades. these devices have traditionally been limited to extending the low-flow operating range at higher rotational speeds for compressors used in compression-ignition (ci) engines. the use of ported shrouds on compressors for spark-ignition (si) engines has been avoided due to operating at pressure ratios below the range where ported shrouds improve low-flow range, the slight decrease in efficiency, and the perception of increased noise. this study examines the performance of a si engine turbocharger compressor with and without a ported shroud through experimental investigation. the results show that by keeping the pressure difference between the two compressor heads constant and preventing the increase in turbine losses and the compressor increased the flow rate of the input flow by about 8%. also, with increasing height of porter shroud compressor 66 to 38 mm, mass flow rate increases 6 to 7 %.