Intercooler model for unsteady flows in engine manifolds

A model has been developed for intercoolers which are used to reduce the temperature of the charge air in turbocharged internal combustion engines. The detailed theory for the intercooler model is presented. The behaviour of the intercooler is characterized by the relationship between the number of transfer units ( N TU ) and the effectiveness (ε) of the intercooler, which is assumed to be that of a cross-flow heat exchanger. The structure of the code used to implement the model is presented and the model is applied to simulate the gas dynamics in a medium-speed turbocharged and intercooled diesel engine. The results show the predicted variation of pressure, temperature and mass flowrate across the intercooler and also the variation of intercooler effectiveness with mass flowrate.