Axial turbine with parallel flow compressor

A turbocharger configured to receive an exhaust gas stream from an engine, and input air from an air source, comprising:

• a turbocharger housing including a turbine housing and a compressor housing;
• and
• a rotor configured to rotate within the housing along an axis of rotor rotation, the rotor including a turbine wheel, a compressor wheel, and a shaft extending along the axis of rotor rotation and connecting the turbine wheel to the compressor wheel;
• wherein the turbine wheel and the turbine housing form a turbine configured to extract energy from the exhaust gas stream, and to thereby drive the rotor in rotation around the axis of rotor rotation;
• wherein the compressor wheel and compressor housing form a compressor configured to compress the input air into the pressurized air stream when the rotor is driven in rotation around the axis of rotor rotation by the turbine wheel;
• wherein the turbine is configured to limit the static pressure upstream of the wheel near the wheel hub to a value that is not greater than 120% of the turbine outlet static pressure for at least some operating conditions;
• and
• wherein the compressor is configured to produce substantially no axial load on the rotor.