Research Activities
and Collaborations
Internal Combustion Engine Group
Department of Energy, Politecnico di Milano, Italy
www.engines.polimi.it
POLITECNICO
DI MILANO
The Department of Energy
Currently involves 110 academics and 100 young
researchers  overall 210 professors and researchers
working in the energy field.
Research and teaching on the following topics:
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Internal combustion engines
Powerplants and energy systems
Combustion
Turbo-machinery
Fuel cells
Thermodynamics
After-treatment systems
Acoustics
Nuclear energy
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The Internal Combustion Engine Group
Faculty
Angelo Onorati, Full Professor
Gianluca D’Errico, Associate Professor
Gianluca Montenegro, Associate Professor
Tommaso Lucchini, Associate Professor
Federico Piscaglia, Associate Professor
Giancarlo Ferrari, Full Professor, in retirement
Post-doc researchers
Tarcisio Cerri, post-doc researcher
Augusto Della Torre, post-doc researcher
Andrea Montorfano, post-doc researcher
MSc thesis
PhD students
Amin Maghbouli
Lorenzo Nocivelli
Javier Martínez Rubio
Lorenzo Sforza
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Keyvan Shaabani
Ehsanallah Tahmasebi
Isabella Verri
Yan Wu
15 – 20 per year
Visiting PhD
Aalto, Sidney, Chalmers,
Freiberg, Valencia, etc.
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DI MILANO
Motivation
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DI MILANO
 Consolidated research activity (since 1990) in development and
application of advanced simulation models for the calculation of the
thermo-fluid dynamic processes in internal combustion engines
and fluid machines:
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Unsteady, turbulent reacting flows in moving geometries.
 Numerical models now part of design process in IC engines:
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Design and development time drastically reduced
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Capability to understand the relevant physical processes and their
interactions, making possible to identify new solutions.
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Research activities
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DI MILANO
The group activities focus on the study of combustion, propulsion and energy systems;
fundamental research involves the study of fluid dynamics, combustion, pollutant formation,
heat transfer, sprays, chemical kinetics, noise reduction. Numerical models to describe
evolution of complex flows are implemented in:
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3D numerical code (OpenFOAM®/Lib-ICE)
Advanced one-dimensional code (GASDYN).
Developed codes and libraries are applied to improve the understanding of physical
phenomena and to guide the experimental activity of engine designers towards promising
configurations, in order to shorten optimization, development and prototyping times of new
internal combustion engines.
The mission of the ICE group is to provide industry and research labs with opportunities to
participate in original, leveraged research in focused thrust areas. The ICE group also
provides educational opportunities for graduate students, and therefore it is an excellent source
of potential employees for Companies.
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Publications
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ICE Group’s research work is published in the following
journals:
o Combustion Theory and Modeling – Taylor and Francis
o Combustion and Flame – Elsevier
o Computer and Fluids – Elsevier
o Int. Journal of Sound and Vibrations – Elsevier
o Energy – Elsevier
o Energy and Fuels – ACS
o Energy Conversion and Management – Elsevier
o Fuel – Elsevier
o International Journal of Engine Research – SAGE
o International Journal of Engineering for Gas Turbine and Power – ASME
o International Journal of Heat and Fluid Flows – Elsevier
o International Journal of Vehicle Design – IJVD
o Mathematical and Computer Modeling – Elsevier
o Proceedings of the Combustion Institute – Elsevier
o SAE Journals (Int. J. Fuel and Lubricants; Int. J. Engines)
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Publications
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DI MILANO
Recent research results of ICE group are presented and
discussed in different selected events.
Conferences:
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Open-source CFD International Conference
SAE World Congress (Detroit)
SAE International Conference on Engines and Vehicles (Capri)
THIESEL Conference (Valencia)
Workshops:
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ECN (Engine Combustion Network) workshop
OpenFOAM® workshop
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Research strategy
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DI MILANO
The ICE group activities focus on the study of combustion, propulsion and energy
systems; fundamental research involves the study of gasdynamics, combustion,
pollutant formation, heat transfer, fluid-dynamics, sprays, chemical kinetics, noise
reduction. Numerical models are implemented in advanced one-dimensional
(GASDYN) and multi-dimensional (Lib-ICE) fluid-dynamic codes for the solution of
complex flow problems.
180 CAD BTDC
65 CAD BTDC
13 CAD BTDC
 FUNDAMENTAL STUDIES: to improve the understanding of physical and
chemical
phenomena occurring in IC engines and fluid machines;
Velocity
CO (range: 0-0.03)
2
 APPLIED RESEARCH: to provide computational tools which can help the
designed in development of low-emissions and high-efficiencies engines.
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POLITECNICO
DI MILANO
CFD code: OpenFOAM®
• Ready to use CFD code
 Applications and model state of the
art available for generic CFD
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heat transfer, aerodynamics,
compressible/incompressible flows, multiphase…
Automatic polyhedral mesh generation
Fully parallel
• Open-source
 No license costs
 Code customization
 Research in collaborative
environment
• Object-oriented C++
 Generic programming
 Easy development of new models
(classes) and applications (solvers)
 Equation mimicking
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class turbulenceModel
{
volScalarField mut_;
virtual void correct() = 0;
class kEpsilon
:
public turbulenceModel
{
volScalarField k_;
void correct();
k
1
 
   uk       t k    t  u  uT   0 k
t
2
 k0


2
void kEpsilon::correct()
{
solve
(
fvm::ddt(k)
+ fvm::div(phi,k)
+ fvm::laplacian(nu() + nut), k)
==
nut*magSqr(symm(fvc::grad(U))
- fvm::Sp(epsilon/k, k)
);
}
CFD code: Lib-ICE
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POLITECNICO
DI MILANO
Set of libraries and solvers for IC engine modeling using
OpenFOAM® technology:
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Mesh motion for complex geometries
Combustion
Lagrangian sprays + liquid film
Unsteady flows in intake and exhaust systems: plenums,
silencers, 1D-3D coupling.
 Reacting flows in after-treatment devices: DPF, catalyst, SCR.
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ICE Group’s research topics
1)Internal combustion engines
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Combustion and pollutant formation;
GDI and Diesel sprays;
Moving mesh algorithms;
Alternative fuels for I.C. engines;
Reacting flows and after-treatment devices;
Large Eddy Simulation of engine-like geometries;
Integrated 1D-3D fluid-dynamic models;
Noise and acoustics.
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DI MILANO
Exp.
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DI MILANO
GDI engines
Effect of SOI timing on
Spray and wall film evolution during injection
mixture quality at spark-timing
process in a stratified GDI engine
Calc.
8CAD ASOI
12CAD ASOI
16CAD ASOI
Fuel mass fraction and liquid spray
distribution as function of number of
injection events (1 vs 3) during intake
stroke. Full-cycle simulation of a
turbocharged GDI engine.
Results are courtesy of Magneti Marelli
(Bologna - Italy)
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Spark-ignition combustion
Comprehensive model for
prediction of flame propagation
process in SI engines:
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Ignition (Lagrangian)
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Electrical circuit
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Flame propagation (Eulerian)
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Plasma channel dynamics
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Flame holder effect
50000
2
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3
1.6
1000 rpm
1.2
1
40000
Temperature [K]
Diameter [mm]
Evolution of sparkchannel diameter and
temperature versus
time:
1) Heat conduction
2) Stretched laminar
flame
3) Turbulent flame
0.8
2
0.4
1000 rpm
30000
20000
10000
0
0
0
0.06
0.12
0.18
Time after spark [ms]
0.24
0
0.06
0.12
0.18
Time after spark [ms]
0.24
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Diesel combustion
Comparison of flame structure computed
by different combustion models (well-mixed
and multiple representative interactive
flamelets - MRIF) implemented in LibICE
Prediction of flame stabilization
process using well-mixed, MRIF and
stochastic PDF combustion models
Well-mixed
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MRIF
PDF
After-treatment: SCR
• Unsteady flow solver with Lagrangian tracking of particles.
• Multi-component liquid mixture and homogeneous chemical
reactions (urea thermal decomposition).
• Wall film formation and evaporation.
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DI MILANO
Selective catalytic reduction (SCR)
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The chemical and physical processes to be taken into
account are:
• the injection and evaporation of urea solution;
• the thermal decomposition of urea in gas phase;
• the hydrolysis of isocyanic acid generated during the urea
thermal decomposition process;
• the reactions of NOx reduction (fast and standard) occurring onto
the catalytic bed:
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LES of cylinder-like geometries
Subgrid scale (SGS) models implemented in
OpenFOAM®/Lib-ICE.
Grid used for the simulations:
4.8 million hexahedral elements,
including the plenum.
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DI MILANO
CFD modeling of open-cell foams
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Micro-CT (x-ray tomography)
Conjugate heat-transfer
simulation
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Coupled 1D-3D (CFD) simulation
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1D code GASDYN coupled to OpenFOAM®:intake air-box, 3D domain
Fully tetrahedral mesh, 18000 cells
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Coupled 1D-3D (3Dcell) simulation
1D-quasi3D integrated model
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ICE Group’s research topics
2) Organic Rankine cycle:
• Exhaust heat recovery, CFD analysis of
volumetric expanders for ORC
Volumetric vane
expander
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DI MILANO
ICE Group’s research topics
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DI MILANO
3) Stirling engine:
• Renewable energy, CFD analysis
of a alpha-type machine
3D mesh, 40000 cells
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ICE Group’s research topics
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4) Downstream the well
Eulerian-Eulerian two phase model for the prediction of the gas-liquid
phase separation
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ICE Group’s research topics
5) External aerodynamics:
• CFD study of external aerodynamics:
lift, resistance, cooling flow, ...
• Shape optimization and design
support
• Applications: ground vehicles,
outdoor structures, ...
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Industrial collaborations
OpenFOAM® Development and Application
• Caterpillar
CFD modeling of spray and combustion
• CINECA
CFD modeling (RANS / LES)
• ENI
CFD simulation of micro-porous media
• FPT Industrial
CFD simulation of Diesel combustion with detailed
chemistry
• Lafranconi silenziatori
1D-3D simulation of silencers
• Magna Powertrain
CFD simulation of exhaust heat recovery
• Magneti Marelli
CFD modeling of direct injection in I.C. engines
CFD simulation of urea injection, SCR
• Mahindra Racing
1D-3D simulation of motorcycle engines
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Industrial collaborations
OpenFOAM® Development and Application
Physical and numerical models
implemented in an open-source code
(LibICE, based OpenFOAM®)
VIRTUAL ENGINE (CFD)
Design and development of
engine components
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Model validation
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DI MILANO
Academic collaborations
• Argonne National Labs
• Chalmers University of
Technology
• Ohio State University (CAR)
• ETH - Zurich
• University of Bologna
• Exeter University
• University of Louvain
• Freiberg University
• University of Valencia (CMT)
• Istituto Motori - CNR Naples
• Imperial College
• University of New South Wales
(UNSW)
• KTH – Royal Institute of
Technology
• Vrjie Universiteit Bruxelles
(VUB)
• Lund University of Technology
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• Malaysian Campus of
Nottingham University