The purpose of LES4ECE is to provide an international forum 
for discussion concerning the research, development and 
application of high-fidelity CFD approaches and related 
experimental techniques in the study, design and optimization 
of energy conversion related to fluid dynamics inside key 
components of thermal, hybrid and electric powertrains as  
internal combustion engines (ICE), electric motors (EM), 
cooling devices and heat exchangers.
By broadening the scope of the well-known LES4ICE conference 
series, LES4ECE’21 aims to support the change of research 
topics in the field of high-fidelity flow simulations for 
modern and future powertrain designs, with the ambition to 
provide an up-to-date forum addressing major developments in 
the mobility sector.


LES AND ITS POTENTIAL

Further improving the environmental performance of 
powertrains requires pushing back the prediction limits of 
simulation tools. Over the last few decades, Large-Eddy 
Simulation (LES) has attracted a great deal of interest, not 
only in academic research, but also increasingly for specific 
industrial flows, for which a time-resolved, non-statistical 
prediction of large flow scales is essential to capture key 
aspects and ensure more reliable prediction. These phenomena 
include mixing in turbulent flows with concentration or 
density/temperature stratifications, strong unstable and non-
periodic features, and more generally flows in which the 
assumption of isotropic and possibly homogeneous turbulence 
described by a statistical approach is not appropriate.

Initially developed within the framework of the Navier-Stokes 
(NS) approaches, the key principle of LES – to precisely 
resolve large flow scales and to model the effects of small 
unresolved scales – is also at the basis of other approaches 
for calculating fluid dynamics which are gaining interest for 
present and future applications such as Lattice-Boltzmann 
methods (LBM) or Smoothed Particle Hydrodynamics (SPH).

SCOPE OF LES4ECE

From a fundamental point of view, although flows inside ICE 
and EM or other powertrain devices exhibit some fundamental 
differences, they share common key features that can be 
addressed using very similar approaches and codes, making 
research originally addressing ICE also relevant to address 
other powertrain devices.
In terms of specific features, ICE flows require addressing 
high-speed turbulent aerodynamics in comparatively  large 
volumes, high-pressure fuel injection, break-up and mixing, 
as well as the interactions between turbulence and chemical 
reactions. EM are subject to turbulent non-reactive flows in 
small passages, and can exhibit low pressure two-phase 
phenomena and wall films in the case of liquid cooling.
A common feature for flows inside ICE, EM and other 
electrified powertrain components is the heat exchange 
between a turbulent, single- or two-phase flow and complex 
walls for cooling or heating purposes. Addressing the 
underlying Conjugate Heat Transfer (CHT) problem requires 
comparable modelling and methodological approaches. A core 
scientific challenge is the significant difference in time 
and space scales between the fast convection and conduction 
in the fluids, and the slower conduction in solids. This 
requires adapted CHT methodologies to yield reliable 
predictions at a reasonable computational cost which becomes 
a primary concern when combined with LES. Among the many 
physical phenomena to be taken into account in such 
situations are thermal boundary layers, the formation and 
evolution of liquid wall films, and phase changes or 
rheological effects in the fluids under the influence of high 
temperatures and intense heat fluxes. 

Furthermore, past experience has shown that it is crucial in 
the context of LES to have appropriate experimental data to 
implement, validate and complement its predictions. Space- 
and time-resolved, quantitative experimental data is required 
for the validation and calibration of LES subgrid-scale 
models for turbulent convection and mixing, multi-phase 
phenomena, chemical reactions and combustion, thermal wall 
boundary layers, or heat radiation. Related experiments 
consist of academic set-ups that allow well-controlled and 
accessible conditions, while being representative of the real 
operation of practical interest.
Experimental data is also indispensable for providing local 
and global, time-resolved and averaged data required to 
support the implementation of LES methodologies to simulate 
the performance of a component or system under real operating 
conditions, and to validate and complemen t its predictions.
LES4ECE aims to include experimental techniques as in 
particular optical diagnostics (e.g. PIV, LIF, LIP, etc.) to 
characterize all aspects of fluid flows (velocities, mixing 
state, dispersion, liquid wall films, temperatures), as well 
as techniques to measure temperature and heat fkuxes at wall 
boundaries (thermocouples, LIP, IR sensing, etc.). It is only 
by combining LES and experiments that breakthrough can be 
achieved in terms of understanding and controlling complex 
flows and their interactions with the walls.

In summary, LES4ECE aims to cover this broad spectrum of 
high-fidelity simulations and experimental techniques 
required to deal with the complex flows found inside modern 
electrified powertrains, as they share a number of common 
challenges and require similar approaches. We strongly 
believe that the resulting cross-fertilization between these 
fields, and the exchanges between researchers and engineers 
working in them, is of high benefit to the community.

LIST OF TOPICS AND CALL FOR PAPERS

Please go to the conference web page to read a detailed list 
of topics, prepare an abstract and submit it.