Turbocharging is a method of increasing the power output from reciprocating engines by utilizing the waste energy in the exhaust gases. The exhaust gases drive a turbine, which provides power to a compressor pressurizing the air at engine inlet, allowing more fuel to be burned. The advantages of this are increased power, reduced specific fuel oil consumption and reduced thermal loading.
Automotive engines typically use the pulse turbocharging method in which the turbine inlet is closely coupled with the exhaust manifold. As a consequence, the turbine is subjected to a highly pulsating flow field caused by, and synchronized with, the opening and closing of the engine valves. However, there is a lack of understanding of the turbine aerodynamics under pulsating conditions. As a consequence of this, over the past decade the Thermofluids Section at Imperial College, London, has focused on researching the aerodynamics of turbocharger turbines under pulsating flow conditions.