Simulation on one-stage and two-stage turbocharged diesel engines at different altitudes

Problems like low mass flow rate, low power output, over-speed of turbochargers and surge often occur when a diesel engine uses one turbocharger at high altitudes. These can be improved if two-stage turbocharging system is used instead of one-stage system. Simulation studies on one-stage and two-stage turbocharged diesel engines at different altitudes were conducted in this paper. Results show that the maximum torque and rated power at 5.5 km altitude increase by 15.5% and 27.2% respectively when using two stage turbocharging system. Low speed torque also increases and both compressors works high efficiently without over-speed.