Scale-resolving simulations in engine combustion process design based on a systematic approach for model development

Abstract

The increasing availability of high-performance computing resources will allow scale-resolving simulations such as large eddy simulations to be used instead of unsteady Reynolds-averaged Navier-Stokes approaches, not only in academic research but also for engine combustion process development. The scope of this work is to highlight and discuss this transition to scale-resolving simulations and to propose a systematic approach for model development and application. The current and future scope of industrial and academic research is discussed especially with respect to cycle-to-cycle variations, which cannot be identified with unsteady Reynolds-averaged Navier-Stokes models. The individual processes along the cause-and-effect chain leading to cyclic variations of the combustion process are identified, and the current state of scale-resolving simulations and the required models with respect to these processes are discussed.

12th International Congress of Engine Combustion Processes: Current problems and modern techniques (ENCOM2015)

“…Traditionally for this conference series, one session deals with new aspects of measurement techniques and another one with modeling and numerical simulations. Five of the contributions have been presented in the form of invited keynote lectures, four of them reviewing aspects of diesel engine design by Miles and Andersson, 2 fuels for future engine concepts by Hoppe et al, 3 scale-resolving simulations (SRS) using high power computation resources for engine combustion by Hasse 4 and of SI engine development by Spicher and Magar. 1 In an additional keynote lecture, the new 3-cylinder TwinPower turbo gasoline engine inside the i8 hybrid car from BMW has been introduced.…”

“…The third review paper by Hasse 4 gives detailed information on SRS such as large eddy simulations (LES) instead of the often applied Unsteady ReynoldsAveraged Navier-Stokes (URANS) approaches to be used not only in academic research but also for engine combustion process development.…”

“…1 The first three review papers mentioned are also included in this Special Issue. [2][3][4] This Special Issue is a selection of 13 papers presented at the ENCOM congress covering several different aspects within the broad range of engine combustion. Only those papers have been selected and submitted for peer review in the International Journal of Engine Research which promise to provide new information in the field or which own at least in some aspects a review-like character.…”

Investigation of an IC Engine Intake Flow Based on Highly Resolved LES and PIV

“…A more detailed overview of the importance of the tumble and its influence on subsequent processes (e.g. fuel-air mixing and flame propagation) is described in [1,2]. In several studies it was shown that the momentum introduced by the intake jet is the main contributor to the large-scale tumble [3][4][5].…”

A PIV-Guided Large-Eddy Simulation of In-Cylinder Flows

“…In view of the underlying assumptions, LES requires validation in order to check their reliability in view of a future usage in engine development processes. Many groups have validated their simulations of motored in-cylinder flows using PIV measurements [12,14,19,20]. The validation is typically based on the comparison of velocity profiles along selected lines.…”