Heat Transfer Modeling for Turbocharger Control

Abstract: Turbocharging is a way to stay competitive on the market where there are increasing demands on fuel consumption and engine performance. Turbocharging lets the engine work closer to its maximum power and thereby reduces the relative losses due to pumping and friction. The turbocharger is exposed to big temperaturedifferences and heat flows will occur both internally between the turbine and the compressor as well as between the turbocharger and its surroundings. Away to get a better understanding of the behaviour of the turbocharger is to understand the heat flows better. This thesis is therefore aimed at investigating theeffect of heat transfer on the turbocharger. In the thesis, different ways of accountfor the heat transfer within the turbocharger is investigated and a heat transfermodel is presented and validated. The model can be used as a tool to estimate theimportance of different heat flows within the turbocharger. A set of heat transfer coefficients are estimated and the heat transfer is modelled with good accuracyfor high engine loads and speeds.