Modelling of door cavities and simulations to assess ow properties in door cavities for dirt/dust applications
Typ
Examensarbete för masterexamen
Program
Automotive engineering (MPAUT), MSc
Publicerad
2021
Författare
Kukreja, Sagar Mahesh
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
In the automotive industry, where lead times are long and prototypes expensive, simulation driven designs
play a vital role to reduce the overall cost and development time. Various tools utilizing Computational Fluid
Dynamics (CFD) are used to e.g. evaluate the aerodynamic performance of vehicles. Firstly, the automotive
industry is in the midst of a switch from combustion to electrified vehicles, hence it is essential to improve
vehicle efficiency in order to increase the range of the battery. Secondly, modern vehicles are equipped with
multiple cameras and sensors connected to driving aid and safety systems. For these systems to function well,
the regions where cameras and sensors are mounted cannot be contaminated by e.g. snow or dust. Finally,
preventing dirt/dust intrusion to the door-cavities of a car is desirable, as dirt/dust present in this region will
likely cause soiling of the occupants when exiting/entering the vehicle.
The Contamination and Core CFD department is responsible for the experimental and virtual assessment of
contamination performance at Volvo Car. In prior tests the in-cavity air
ow at the tailgate cavities have been
evaluated. However, the cavities at the doors were not analysed for dirt/dust intrusions. The objectives of this
thesis is to use previous knowledge and data on how to predict
flow fields in cavities, and from that formulate a
multiphase approach to also include dust/dirt distribution in the simulations by means of experiments and
CFD. The vehicle geometry used for experimentation and CFD analysis is a Volvo V90 D4 AWD. The geometry
to capture the cavities was prepared using ANSA and the following simulations were conducted in StarCCM+.
The vehicle was driven on gravel roads to analyse, compare and validate dust patterns in the door cavities.
The conclusions from the thesis is that it is possible to resolve the door cavities and subsequently simulate the
in-cavity
ow pattern in these cavities using CFD. In general, the dust particle are observed to enter the cavities
at two major regions. First, at cavities between the fender, the front door and the sill moulding. Second, at
cavities between the front door, rear door and the sill moulding.
Beskrivning
Ämne/nyckelord
Multiphase modelling , aerodynamics , in-cavity flow, , dirt/dust intrusions , door cavities , passenger vehicles , CFD simulations , StarCCM+ , ANSA , contamination , self-contamination