Thermal Modelling of Heat Transfer Between Ambient Air and Powerpack
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Applied mechanics (MPAME), MSc
Publicerad
2023
Författare
Larsson, Axel
Rangaswamy, Sunil
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
This report presents the creation and evaluation of an air-cooling steady state model
for a Volvo Cars powerpack. It should simulate the heat transfer and temperatures
from the components of the powerpack. Especially interesting is how the NVH
(Noise Vibration Harshness) encapsulation affects the cooling performance. This
encapsulation is a thin foam layer that surrounds the motor and dampens the noise
caused by it. A 1D model already existed that handled the internal heat generation
and the liquid cooling of the powerpack. Twenty chosen operating conditions were
iteratively calibrated between the 1D model and a full car 3D model to yield heat
transfer coefficients (HTC) for each thermal node in the extension. They were chosen
as variable sweeps (sweeping over multiple values for one variable while keeping the
rest constant) from a central base case, yielding four to five data points to analyse
each variable’s impact separately. The results show that the air-cooling increases as a
fraction of the total cooling as the car velocity and driveshaft torque increases. It also
shows that most air-cooling bypasses the encapsulation, meaning the encapsulation
has little impact on the performance. When compared with physical measurements
the accuracy of the model is low. This is most likely caused by the lack of calibration
for operating conditions where multiple variables were changed from the base case. It
is therefore recommended that future work includes additional operating conditions
to simulate. This could not be done in this project due to time and computational
constraints.
Beskrivning
Ämne/nyckelord
Air cooling , BEV , GT-SUITE , Powerpack , Simulation , STAR-CCM+ , Temperature , Thermal management