One-dimensional simulation of the pressurized motoring method : friction, blow-by, temperatures and heat transfer analysis

Abstract

Mechanical friction in internal combustion engines is nowadays largely optimized as a result of long years of research in this field. The ever increasing demand for better performance and less emissions however still puts mechanical friction as one of the areas in which further improvements can be done. This requirement calls for more accurate one-dimensional simulation models, along with reliable and robust experimental data to support such models. At University of Malta, a Pressurized Motoring test rig was developed and reported in SAE paper 2018-01-0121. Such method has proved to be relatively accurate in determining the mechanical friction of an internal combustion engine. As compared to the conventional Indicating technique, Morse test and Breakdown test, the Pressurized Motoring method offers the robustness that the uncertainty in the FMEP, as a result of error propagation is kept low. Furthermore, amendments to the traditional Pressurized Motoring technique were also done and presented in SAE paper 2019-01-0930, where Argon was used in place of Air to raise the bulk in-cylinder peak temperature to a value similar to what is found in a fired engine. In this proposal for publication, the authors now discuss a simple one-dimensional simulation model whose results are compared with those obtained and reported in SAE paper 2019-24-0141. Such work is aimed to test traditional friction and heat transfer models in one-dimensional software whilst identifying potential optimizations that can be done to the developed Pressurized Motoring test rig for its data to be more appealing to the one-dimensional researcher.