Method of controlling a valve of a dual volute turbocharger

A method of controlling a valve of a dual volute turbocharger for use with an internal combustion engine, with the dual volute turbocharger configured to receive exhaust gas from the internal combustion engine and deliver compressed air to the internal combustion engine, the dual volute turbocharger comprising,

• a turbine housing comprising,
• a turbine housing interior adapted to receive a turbine wheel,
• a first volute adapted for fluid communication with the internal combustion engine and the turbine housing interior for delivering exhaust gas from the internal combustion engine to the turbine housing interior,
• a second volute adapted for fluid communication with the internal combustion engine and the turbine housing interior for delivering exhaust gas from the internal combustion engine to the turbine housing interior independently of the first volute, and
• a turbine housing outlet in fluid communication with the turbine housing interior for discharging exhaust gas from the turbine housing interior,
• a wall separating the first volute from the second volute,
• a valve seat,
• the turbine wheel disposed in the turbine housing interior, and
• a valve engageable with at least one of the valve seat and the wall of the turbine housing for controlling exhaust gas flow from the first and second volutes to the turbine housing interior, with the valve and the wall of the turbine housing collectively defining a first cross-sectional flow area and the valve and the valve seat of the turbine housing collectively defining a second cross-sectional flow area, and with the valve movable between a closed position where the valve restricts exhaust gas from flowing between the first and second volutes and from bypassing the turbine housing interior, and an open position where the valve allows exhaust gas from the first and second volutes to bypass the turbine housing interior, and
• a controller operable to
• receive at least one signal from at least one sensor, with the at least one signal corresponding to an operating value related to the internal combustion engine and/or the dual volute turbocharger, and with the at least one signal corresponding to a turbine energy of the dual volute turbocharger, and
• direct the valve based on the operating value and the turbine energy of the dual volute turbocharger,
• said method comprising the steps of:
• determining a current position of the valve;
• determining the operating value;
• determining the turbine energy of the dual volute turbocharger;
• determining a desired position for the valve between the closed and open positions based on the operating value and the turbine energy of the dual volute turbocharger for providing a desired flow of exhaust gas from the internal combustion engine to the turbine housing interior;
• comparing the current position of the valve and the desired position for the valve;
• and
• directing the valve based on the comparison of the current position and the desired position to provide the desired flow of exhaust gas from the internal combustion engine to the turbine housing interior,
• wherein when the valve is in the desired position, the valve has an area ratio constant (CAR) of from 0.0001 L/kW to 0.150 L/kW, with the CAR defined by the equation:
• CAR=first cross-sectional flow area/(ρpower*second cross-sectional flow area).