Abstract
In the thesis at hand the study of heat tranfer phenomena and thermal balance inside the engine structure, as well as in the cooling system is addressed. It has been the main goal of this thesis the use and extension of a model for the prediction of combustion chamber wall temperatures, along with the application of two commercial computational thermohydraulic programs, to the study of heat flows inside and outside the engine structure in order to assess the engine energy balance under steady and transitory operation, and also to design or redesign new cooling systems for locomotive engines. To accomplish the aforementioned goal some steps explained along this document, were followed. Those tasks consisted on: a thorough review of the heat transfer models used to calculate the heat flows in all the internal combustion engine boundaries; the enhacement of a predictive wall temperature model to detail all the heat flows between metallic parts and boundary media; the experimental study of the engine warm-up under a driving cycle to study its energy balance, and to propose low cost modifications to the original cooling system intended to accelerate the engine warm-up; the modelling and assessment of the proposed modifications in terms of their impact on the engine warm-up time, as well as on the fuel consumption and emissions; and, finally,  the development and implementation of a methodology flor the initial design, modelling and simulation of engine cooling systems for special applications.