FraunhoFer Project GrouP For new Drive SyStemS naS

F r A u N H o F e r P r o j e c t G r o u P F o r N e w D r i v e S y S t e m S N A S

hybrid powertrains / electromobility

design

conventional powertrains

Project groupnas

stationary powertrains and heat utilization

testing

simulation Lightweight powertrains

Drive systems for future mobi l i ty concepts, as wel l as energy

sovereignty and susta inable energy suppl ies, are some of the most

s ignif icant sc ient if ic and technological chal lenges faced by society

today. The Fraunhofer Project Group for New Drive Systems

consequent ly a ims to advance appl ied research and pi lot- level

product development in these areas.

The development strategy of the Project Group for New Drive

Systems is ref lected in i ts four f ie lds of research: Hybr id powertra ins

and electromobi l i ty , convent ional powertra ins, stat ionary power-

tra ins and heat ut i l izat ion as wel l as l ightweight powertra in

des ign. In order to conduct sucessful research within these f ie lds,

the NAS draws on internal competence in des ign, s imulat ion and

test ing, as wel l as state-of-the-art software tools and test stands.

Within the competence group des ign, for example, CATIA V5 is

used, whi le Dymola, GT-Power, MatLab Simul ink, S IMPACK, Star

CCm+ and Ansys fac i l i tate work for the s imulat ion and des ign

teams. Modern in-house test stands are avai lable for the test ing of

appl icat ion-or iented concepts.

F r a u n h o F e r P r o j e c t G r o u P

F o r n e w d r i v e s y s t e m s n a s

Dr.-ing. Hans-Peter Kollmeier

Head of Project Group

Phone +49 7 21 9150-3811

Fax +49 7 21 9150-38810

hans-peter.kollmeier@ict.fraunhofer.de

HyBriD PowertrAiNS AND eLectromoBiL ity

The ongoing efforts focus on increasing the range, comfort

and usability by optimizing individual components and the

entire system. Research activities are divided into the areas

of drive trains, batteries, electrics/electronics and thermal

management. In order to achieve the project objectives,

researchers from each field are working on processes such as

trials on HIL test stands, vehicle simulation or the constructive

implementation of cooling concepts for power electronics.

StAtioNAry PowertrAiNS AND

HeAt utiL iZAtioN

All research work in these fields aims at the development of

innovative heat and power cogeneration units to increase

the efficiency of complete combined heat and power plants

(CHPs). The main objective is the integration of suitable

electric and thermal storage systems to allow an energy

supply that is independent of the energy converter. The most

promising systems are thermo-chemical storage devices based

on zeolite or latent thermal storage devices based on PCM. In

close cooperation with the Energetic Systems Department of

the Fraunhofer ICT, the entire development chain, from setting

the required framework conditions for thermal storage de-

vices, and material characterization, through to the design and

construction of thermal storage prototypes, can be covered. In

the department‘s research on powertrains, emphasis is placed

on the durability of the energy converter, and on achieving the

longest possible maintenance interval.

reSearch areaS

coNveNtioNAL PowertrAiNS

Legislative requirements regarding the minimization of CO2

emissions, and the price development of fossil energy sources,

are forcing vehicle manufacturers to improve the efficiency of

their products and to develop sustainable mobility concepts.

Research in the field of conventional powertrains focuses on

increasing the efficiency of combustion-engine powertrain

concepts and electrified drive train topologies. Our key fields

of research are:

Evaluation of innovative drive train concepts and their

components

Waste heat recovery

Friction minimization

Operating and testing strategies

L iGHtweiGHt PowertrAiNS

In this field, we focus on possible ways to increase effi-

ciency by reducing the weight of moving and non-moving

components in conventional and electrified drive trains for

mobile applications. The use of lightweight materials such as

lightweight metal, composites and ceramics, and especially

the combination of these materials in hybrid constructions,

generates a weight advantage over conventional, metal con-

struction methods. Emphasis is placed on projects requiring

a material and process-oriented construction of lightweight

powertrain components.

F r a u n h o F e r P r o j e c t G r o u P

F o r n e w d r i v e s y s t e m s n a s

Thermal optimization of the cooling circuit of

a single-cylinder research engine developed

in-house by using numerical flow-structure

coupling.

SimuLAtioN

The simulation team works on the modeling and analysis

of individual components and entire systems. The task of

developing and manufacturing these components and systems

is usually very complex and time-consuming. It is therefore

important to carry out the development from the initial idea

to the finished component with as few corrections as possible.

These demands make simulation an essential part of the

development process, enabling early identification of potential

and weaknesses and the implementation of this knowledge in

the development process. Thus simulation makes it possible to

verify new constructions while minimizing the testing efforts.

In order to assess the behavior of individual components in

the system, NAS uses simulation tools for the transfer of heat,

material and information, for example “Dymola“ or “GT-Suite“.

The components are modeled physically or on the basis of a

map. The tool “IPG-CarMaker“ can conduct a simulation for

the entire vehicle. Vehicles can be split into different modular

subsystems, and their efficiency can be assessed during dri-

ving, which enables the improved consumption of the tested

technologies to be calculated in driving cycles.

Drive systems include many flow processes with a wide variety

of characteristics and physical complexities, for example gas

mixture flows during charge conversion in the combustion

engine or fluid flows such as those in cooling circuits. For the

detailed analysis and assessment of these flows, professional

CFD tools such as “Ansys Fluent“ and “StarCCM+“ are used.

DeSiGN

Researchers in the competence group design work closely

together with the teams for simulation and testing to find

technical solutions for challenges arising in the various

research areas. Each group is responsible for the optimization

of existing components and systems, and also the develop-

ment of completely new, complex systems such as expansion

machines for waste heat recovery systems. Developments

include prototypes for the validation of new operating

principles or layout concepts for thermal energy converters

such as turbines or piston engines.

Development work is often centered on new materials and

manufacturing processes. One research project includes the

substitution of metal alloys by high performance composite

materials in combustion engine components; in another,

the application of selective laser melting (SLM) for the

manufacturing of raw parts allows for more creativity in the

design and thus for optimized components. We also work on

the packaging of electronic components developed in-house

for electric powertrains. Various projects also include packa-

ging concepts for entire conventional or electrified vehicle

powertrains. In order to ensure the comparability of different

samples, safe installations and simple assembly, all test stands

and their peripherals are developed and documented virtually

in the CAD system.

comPetenceS

Hot gas test stand for the investigation of

energy recovery units in the waste gas stream

Waste heat recovery

Organic Rankine Cycle

Exhaust-gas turbocharger

Aging investigations

Exhaust gas treatment systems

F r a u n h o F e r P r o j e c t G r o u P

F o r n e w d r i v e s y s t e m s n a s

The NAS project „Construction and commission of a hot gas burner test stand for system analyses of electrified

power trains“ is funded by the EU operational program „Regional Competitiveness and Employment Objective –

ERDF“ (European Regional Development Fund) and the Ministry of the Environment, Climate Protection and the

Energy Sector of Baden-Württemberg. For further information on Regional Competitiveness and Employment

Objective – ERDF please contact the Ministry for the Rural Area and Consumer Protection of Baden-Württemberg

or visit www.rwb-efre.baden-wuerttemberg.de.

A clear transition towards lightweight design can be seen in

the research and industrial sectors. Materials must be light, solid

and temperature-resistant. The research team for simulation

contributes to this transition by providing structural analyses

enabling the verification and optimization of the component

design. Here, the simulation software “Ansys Mechanical“ is

used. The Project Group NAS works with technologies that are

often highly dynamic. In order to visualize the influence of dyna-

mic effects on the component behavior, multi-body simulations

are conducted using the simulation program “Simpack“.

teStiNG

In the testing group, various experiments are conducted

involving the different fields of research. The measurement

results obtained are used to validate simulation models and

develop suggestions to improve the construction. For this,

cutting-edge testing facilities are available. Complete measure-

ments of multi-cylinder engines of the smaller passenger car

size and single-cylinder test engines can be performed on the

engine test stand. Its setup allows the integration of additional

applications such as waste heat recovery systems into the

existing test stand environment. The combustion engine

can also be integrated into the simulation environment as a

hardware component by a special interface so that the load

acting on the engine is more dynamic and realistic. This allows

the investigation of various drive topologies. In addition, it is

possible to measure the exhaust-gas turbochargers of light

and medium-duty vehicles by using a hot gas test stand.

Experimental analyses of expanders and steam boilers for

ORC-based waste heat recovery systems are also conducted

at this stand and at a smaller, mobile hot gas test stand.

The special setup of the stand permits investigations on the

aging and thermal shock resistance of components such as

heat exchange units, pipelines, and exhaust systems.

The Project Group NAS also uses testing facilities for mini CHP

systems or for the investigation of the urea dosing of SCR

exhaust gas treatment systems. In accordance with a method

developed at the NAS, customer-representative and time-op-

timized testing procedures for drive systems are determined

based on real driving data, taking all influencing factors into

account.

PoSSibilitieS For collaboration

We work with our project partners on pre-competitive

development tasks, both in funded projects on a regional,

national and international level and in direct bilateral coopera-

tion on a contractual basis. In each context we guarantee the

prompt and professional execution of your development tasks.

Bilateral contract research

Collaboration in publicly-funded projects (federal states,

central government, EU)

Service in the fields of construction and simulation

Service in the fields of testing; system, and component

testing

Training / consultancy / workshops

Fraunhofer Project Group

for New Drive Systems NAS

Rintheimer Querallee 2

76131 Karlsruhe

Germany

Head of Project Group

Dr.-Ing. Hans-Peter Kollmeier

Phone +49 7 21 9150-3811

Fax +49 7 21 9150-38810

hans-peter.kollmeier@ict.fraunhofer.de

www.ict.fraunhofer.de

F r a u n h o F e r P r o j e c t G r o u P

F o r n e w d r i v e s y s t e m s n a s

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