nozzle 59 is wide and the inclination angles of the blades 57 are small on the other hand the blade angle u03b2ks of the leading edge 47 of the blade 7 is set small turbines of this shape are called u201c reaction turbines u201d which are highly efficient when u co is large in the case where the mixed flow turbine 1 is used as a variable displacement turbocharger of passenger cars and trucks u co decreases to 0 5 to 0 6 during acceleration whereas u co increases to 0 7 to 0 8 at the maximum power output a usable area ua is used when u co is in the range from 0 6 to 0 7 fig1 is a diagram for describing the dimensionless characteristics of the mixed flow turbine 1 when the valve element 71 is fully closed exhaust gas flows only through the hub side flow channel 63 and is supplied to the hub side of the leading edges 47 through the hub side inlet channel 41 so that an efficient fully closed characteristic 75 is exhibited at low u co on the other hand in the fully open state the exhaust gas flows through the hub side flow channel 63 and the shroud side flow channel 65 and is supplied to the hub side and the shroud side of the leading edges 47 at that time since the quantity of exhaust gas supplied to the shroud side becomes substantially twice as much as the quantity of exhaust gas supplied to the hub side the characteristic of the shroud side flow predominates accordingly an efficient.