Abstract
Demand of two-stage turbocharger is increasing for large engine applications. Generally, these turbo chargers have a
curved duct at the inlet or at the outlet. Such curved duct is required to achieve compact designs, however, these sometimes
lead to drop in performance. Therefore, for a given mount condition, it is important to design such ducts so that performance
reduction is minimized as much as possible. In this paper, the flow pattern of a low-pressure turbine of a two-stage
turbocharger is calculated, and performance reduction as well as its cause is discussed. The results show that, for the specific
case analyzed, turbine efficiency decreases by 4% due to flowing along the outer side of the curved sector of the duct,
however, it is also found impact on turbine wheel performance is small.
