Analysis of Heating, Heat Accumulation, and Cooling Processes in the Engine of the Ultra-Efficient Prototype Vehicle Eco Arrow 3

The article presents the results of a study on heat transfer within the engine block of the Eco Arrow 3 prototype vehicle, developed for participation in Shell Eco-marathon competitions. The main objective of these events is to minimize fuel consumption during track races, which leads to a specific driving strategy characterized by frequent engine shut-downs and restarts. Such a driving style introduces challenges not typically encountered in conventional vehicles, including the need to maintain the engine within an optimal temperature range. In this work, several geometric variants of cylinder finning were investigated with respect to their influence on cooling, heating, and heat accumulation. Four configurations of finning were analysed: the original fins with a height of h = 15 mm, a cylinder with fins completely removed (h = 0 mm), and two intermediate variants with fin heights of 5 mm and 10 mm. The original and finless cylinders were studied both experimentally and numerically, while the intermediate variants were analysed solely using numerical methods. A comparison between experimental and numerical results showed satisfactory agreement in terms of maximum temperatures, with differences of approximately 10–15 °C. Considering the specific operating conditions of such an engine, characterized by irregular on–off cycles, the numerical analysis indicated that fins with a height of h = 10 mm provide the most favourable balance, ensuring that the engine remains within the optimal temperature range required to achieve minimal fuel consumption.