Verification Method to Optimize Multiple Engine Functions in a Short Time Using Multi-Objective Design Exploration

Abstract

<div class="section abstract"><div class="htmlview paragraph">Model-based Development (MBD) has been employed for engine development to reconcile the contradictory relationship between numerous functions and systems at a high level and in a short span of time. However, in actuality, as engines have become more advanced, it has become challenging to even satisfy the requirements of individual components. Moreover, reconciling multiple contradictory functions like engine power and strength and durability performance, as well as coordinating many related systems, requires an even higher level of skill. Such harmonization techniques require total optimization studies that cover a wide range of designs, and which requires several years of examination with current development processes. Multi-objective Design Exploration (MODE) methods [<span class="xref">1</span>] using parametric models [<span class="xref">2</span>] and surrogate models [<span class="xref">3</span>] are being used to shorten the development period and achieve more balanced designs. However, there are few cases in which multiple functions such as structure, fluid, heat, engine emissions (EM), and mechanism have been studied like in engines. Therefore, this study aims to further advance MODE by constructing a method for using multi-objective design exploration to quickly determine specifications that simultaneously satisfy the various related multifunctional engine requirements that are influenced by numerous systems. In this study, we analyzed multiple required values, then constructed and adopted surrogate models for thermal management, engine friction, and EM, which had been considered challenging to model in the past due to the many development issues. We carried out MODE with newly constructed surrogate models in addition to engine power, fuel economy, strength and durability, and NV. This enabled us to quickly narrow down the wide range of design spaces and satisfy required values in a single stroke. We thus report the construction of a new MBD process aimed at reducing overall engine development time.</div></div>