A spatial motion mechanism was designed which could make all the nozzle vanes rotate around the center of ball with the same radius synchronously to realize control of the variable nozzle mixed-flow turbocharger(VN-MT).The back and abdomen of the nozzle vane was designed as arc-shaped.A variable nozzle ring perfectly combined with the mixed-flow turbine was made available.The turbine geometric model of VN-MT was established through the computational fluid dynamics(CFD).Compared with nozzleless mixed-flow turbine,the flow range of variable nozzle mixed-flow turbine was broadened tremendously while the peak turbine efficiency point was lower slightly.Flow field analysis in turbine stage showed that the energy loss of the VN-MT under designed condition was larger and the blade load of rotor was lower than the nozzleless mixed-flow turbocharger.
