Engine assembly with exhaust pipe nozzle

An engine assembly comprising:

• an internal combustion engine having a working chamber of variable volume, and having an inlet port and an exhaust port in communication with the working chamber, the exhaust port having a cross-sectional area Ae;
• a turbine configured as an impulse turbine having a pressure based reaction ratio of at most 0.25, the turbine having a circumferential array of rotor blades extending across a flow path;
• and
• an exhaust pipe providing fluid communication between the exhaust port of the internal combustion engine and the flow path of the turbine, the exhaust pipe terminating in a nozzle communicating with a portion of the flow path located upstream of the rotor blades;
• wherein the nozzle includes a portion of reduced cross-sectional area with respect to a remainder of the exhaust pipe, the nozzle defining a minimum cross-sectional area An of the exhaust pipe;
• and
• wherein a ratio An/Ae between the minimum cross-sectional area An and the cross-sectional area Ae of the exhaust port is at least 0.2.

A method of compounding an internal combustion engine, the method comprising:

• providing a turbine configured as an impulse turbine having a pressure based reaction ratio of at most 0.25;
• drivingly engaging the internal combustion engine and the turbine to a common load;
• circulating exhaust gas from an exhaust port of the internal combustion engine through a first portion of an exhaust pipe having a first cross-sectional area and then through a nozzle of the exhaust pipe having a second cross-sectional area smaller than the first cross-sectional area;
• and
• circulating the exhaust gas from the nozzle to an inlet of the turbine, including directing the exhaust gas onto blades of the turbine.