Unsteady thermal management simulations for a
passenger vehicle using 1D and 3D tools
- Application on actual driving cycles (e.g. WLTC) Background and scientific relevance
Modern research and development efforts relating to combustion engines and vehicle design
are largely driven by the pressing need to reduce the global consumption of fossil energy
carriers and the resulting emissions of the greenhouse gas carbon dioxide. Particularly under
cold-start conditions, fuel consumption and emissions are typically high due to high friction
and heat losses. To reduce the length and intensity of periods of cold-start different methods
are used to retain the heat produced by the engine for as long as possible after engine shutoff.
This will increase the probability that oil and structure temperatures will be high at next
engine start. One way to achieve this effect is by encapsulating the engine in a thermal barrier
to reduce the heat transfer from the engine to the environment.
Project description
Within this project, an existing
GT-Suite model for a passenger
car will be provided, Figure 1.
The goal of the project is to
investigate the effect of thermal
encapsulation on fuel efficiency
in the WLTC (Worldwide
harmonized Light vehicles Test
Cycle), which will replace
the NEDC from 2017 on. To
Figure 1:GT-Suite model
evaluate and quantify the benefits of an encapsulated setup it is necessary to integrate a
temperature dependent engine friction model in the vehicle thermal management model
together with a model of heat transfer due to natural convection after engine shutoff.
Your tasks will include:

Studying and understanding the capabilities of the provided vehicle model (GT-Suite).

Investigate a temperature dependent engine friction model.

Integrate the friction model together with provided thermal management model.

Perform CFD simulations (StarCCM+) of natural convection in the engine bay for a
given vehicle using standard procedure (already available).

Integrate results from 3D CFD simulations in GT-SUITE thermal management model.

Identify challenges and constraints for modifications on the thermal management
system

Simulate the WLTC cycle and sequences of it with cold starts and draw conclusions
about the effects of encapsulation on the overall energy efficiency.
Relevance for the department
At the department the two groups dealing with the powertrain are Vehicle Aerodynamics and
Thermal Management/VATM (cooling) and Combustion (heat production). This project gives
the groups the opportunity to work together in this topic which is crucial for the function of a
vehicle. A continuation of this project could be how to reduce the aerodynamic drag while
maintaining a proper cooling (reduce the so-called cooling drag), or how the cooling of a
hybrid powertrain should be designed (where components with different cooling requirements
are mixed). Both areas are important for the future work at our department, and this project
can be seen as a first step towards a collaboration between the two groups (VATM and
Combustion).
Besides, the student will learn a number of commercial softwares which will be useful later
on his/her career.
Organisation
The project will be supervised by:


Blago Minovski, VEAS, PhD student in Vehicle Aerodynamics and Thermal
Management
Jelena Andric, Combustion, post doc working with design and modelling of future
vehicles
Examiners are:


Lennart Löfdahl, professor, Vehicle Aerodynamics and Thermal Management
Sven B. Andersson, biträdande professor, Internal Combustion Engines
There will be weekly meetings where all of the project participants will be invited. And since
the students will be sitting at our department there will be (the possibility of) a daily contact
with the supervisors.
Expected outcome
The expected outcome is to get information/answers regarding the tasks mentioned above.
This will be indications of how to proceed in the area of thermal management which will be
helpful since there is a strong connection between the formulated proposal and currently
running research projects. The knowledge that will acquired within this project will also be
valuable input for a comprehensive thermal management model for hybrid vehicles.
The students will be encouraged to author/coauthor a conference / journal paper together with
the supervisors and to participate and present the work at an international conference.