Your Selections

Volvo Car Corp.
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Optical Investigation on the Combustion Process Differences between Double-Pilot and Closely-Coupled Triple-Pilot Injection Strategies in a LD Diesel Engine

Volvo Car Corp.-Michael Denny, Håkan Persson
Lund University-Alexios Matamis, Zhenkan Wang, Per Tunestal, Mattias Richter, Öivind Andersson
Published 2019-01-15 by SAE International in United States
The combustion processes of three injection strategies in a light-duty (LD) diesel engine at a medium load point are captured with a high speed video camera. A double-pilot/main/single-post injection strategy representative of a LD Euro 6 calibration is considered as the reference. There is a modest temporal spacing (dwell) after the first pilot (P1) and second pilot (P2). A second strategy, “A,” adds a third pilot (P3). The dwell after both P2 and P3 are several times shorter than in the reference strategy. A third strategy, “B,” further reduces all dwells. Each injection has its own associated local peak in the heat release rate (HRR) following some ignition delay. Between these peaks lie local minima, or dips. In all three cases, the fuel from P1 combusts as a propagating premixed flame. For all strategies, the ignition of P2 primarily occurs at its interface with the existing combustion regions. Extinguishing of the prevailing combustion by the fuel jets of later injections is noted in all strategies. This phenomenon is confirmed by comparing the timing of each…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Supervisory Controller for a Light Duty Diesel Engine with an LNT-SCR After-Treatment System

Volvo Car Corp.-Dhinesh Velmurugan, Daniel Lundberg
Chalmers University of Technology-Tomas McKelvey
Published 2018-09-10 by SAE International in United States
Look ahead information can be used to improve the powertrain’s fuel consumption while efficiently controlling exhaust emissions. A passenger car propelled by a Euro 6d capable diesel engine is studied.In the conventional approach, the diesel powertrain subsystem control is rule based. It uses no information of future load requests but is operated with the objective of low engine out exhaust emission species until the Exhaust After-Treatment System (EATS) light off has occurred, even if fuel economy is compromised greatly. Upon EATS light off, the engine is operated more fuel efficiently since the EATS system is able to treat emissions effectively.This paper presents a supervisory control structure with the intended purpose to operate the complete powertrain using a minimum of fuel while improving the robustness of exhaust emissions. A supervisory controller assisted by look ahead information, and using a supervisory control interface that works in concert with low level local controllers, can make subsystems operate near optimal. The look ahead parametrized supervisory control calculates the set-points for the subsystems: Internal Combustion Engine (ICE), Lean NOx Trap…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Method to Evaluate the Compression Ratio in IC Engines with Porous Thermal Barrier Coatings

Volvo Car Corp.-Joop Somhorst, Mirko Bovo
Chalmers University of Technology-Michael Oevermann, Ingemar Denbratt
Published 2018-09-10 by SAE International in United States
The compression ratio is an important engine design parameter. It determines to a large extend engine properties like the achievable efficiency, the heat losses from the combustion chamber and the exhaust losses. The same properties are affected by insulation of the combustion chamber. It is therefore especially important to know the compression ratio when doing experiments with thermal barrier coatings (TBC).In case of porous TBCs, the standard methods to measure the compression ratio can give wrong results. When measuring the compression ratio by volume, using a liquid, it is uncertain if the liquid fills the total porous volume of the coating. And for a thermodynamic compression ratio estimation, a model for the heat losses is needed, which is not available when doing experiments with insulation.The subject of this paper is the evaluation of an alternative method to assess the compression ratio. It is based on motored cylinder pressure data like other thermodynamic methods but does not need a model for the heat losses. The validation and application of the method is done with data from…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Homogeneous Lean Combustion in a 2lt Gasoline Direct Injected Engine with an Enhanced Turbo Charging System

Volvo Car Corp.-Daniel Dahl
Chalmers University of Technology-Kristoffer Clasen, Lucien Koopmans
Published 2018-09-10 by SAE International in United States
In the quest for a highly efficient, low emission and affordable source of passenger car propulsion system, meeting future demands for sustainable mobility, the concept of homogeneous lean combustion (HLC) in a spark ignited (SI) multi-cylinder engine has been investigated. An attempt has been made to utilize the concept of HLC in a downsized multi-cylinder production engine producing up to 22 bar BMEP in load. The focus was to cover as much as possible of the real driving operational region, to improve fuel consumption and tailpipe emissions. A standard Volvo two litre four-cylinder gasoline direct injected engine operating on commercial 95 RON gasoline fuel was equipped with an advanced two stage turbo charger system, consisting of a variable nozzle turbine turbo high-pressure stage and a wastegate turbo low-pressure stage. The turbo system was specifically designed to meet the high demands on air mass flow when running lean on higher load and speeds. Also, a dual coil ignition system was used for enhanced ignition ability and a lean NOx emissions exhaust after-treatment system (EATS) dummy was…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Automated Aerodynamic Vehicle Shape Optimization Using Neural Networks and Evolutionary Optimization

SAE International Journal of Passenger Cars - Mechanical Systems

Volvo Car Corp.-Alexander Broniewicz, Tim Walker, Christoffer Landström
ÅF Industry-Anton Lundberg, Per Hamlin, Davangere Shankar
  • Journal Article
  • 2015-01-1548
Published 2015-04-14 by SAE International in United States
The foremost aim of the work presented in this paper is to improve fuel economy and decrease CO2 emissions by reducing the aerodynamic drag of passenger vehicles. In vehicle development, computer aided engineering (CAE) methods have become a development driver tool rather than a design assessment tool. Exploring and developing the capabilities of current CAE tools is therefore of great importance.An efficient method for vehicle shape optimization has been developed using recent years' advancements in neural networks and evolutionary optimization. The proposed method requires the definition of design variables as the only manual work. The optimization is performed on a solver approximation instead of the real solver, which considerably reduces computation time. A database is generated from simulations of sampled configurations within the pre-defined design space. The database is used to train an artificial neural network which acts as an approximation to the simulations. Finally an optimal vehicle shape is determined using the particle swarm optimization method. The method is solver independent and can handle multiple objectives.The method was incorporated in an optimization tool compatible…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Effect of Rear-End Extensions on the Aerodynamic Forces of an SUV

Volvo Car Corp.-Simone Sebben, Tim Walker
Chalmers University of Technology-Lennert Sterken, Lennart Lofdahl
Published 2014-04-01 by SAE International in United States
Under a global impulse for less man-made emissions, the automotive manufacturers search for innovative methods to reduce the fuel consumption and hence the CO2-emissions. Aerodynamics has great potential to aid the emission reduction since aerodynamic drag is an important parameter in the overall driving resistance force.As vehicles are considered bluff bodies, the main drag source is pressure drag, caused by the difference between front and rear pressure. Therefore increasing the base pressure is a key parameter to reduce the aerodynamic drag. From previous research on small-scale and full-scale vehicles, rear-end extensions are known to have a positive effect on the base pressure, enhancing pressure recovery and reducing the wake area.This paper investigates the effect of several parameters of these extensions on the forces, on the surface pressures of an SUV in the Volvo Cars Aerodynamic Wind Tunnel and compares them with numerical results. To decrease the dependency of other effects within the engine bay and underbody, the SUV has been investigated in a closed-cooling configuration with upper and lower grille closed and with a smoothened…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

V2V Communication Quality: Measurements in a Cooperative Automotive Platooning Application

SAE International Journal of Passenger Cars - Electronic and Electrical Systems

Volvo Car Corp.-Erik Coelingh
Qamcom Research & Technology-Ali Tehrani
  • Journal Article
  • 2014-01-0302
Published 2014-04-01 by SAE International in United States
This paper presents measurements on Vehicle to Vehicle (V2V) communication between participants in a platooning application. Platooning, according to the SARTRE concept, implies several vehicles travelling together in tight formation, with a manually driven heavy lead vehicle. The platoon being studied consists of five vehicles; two trucks in the lead and three passenger cars. The V2V-communication node in each vehicle contains an 802.11p radio at 5,9 GHz. It is used to send messages between vehicles to coordinate movements and maintain safety in the platoon. Another cooperative application that relies on V2V-communication is multiple UAVs flying in formation; as investigated in KARYON. This project also investigates cooperative autonomous vehicles. In both applications, V2V-communication is an enabling technology. Two metrics are studied to quantify the V2V-communication quality: system packet error rate and consecutive packet loss. These two metrics characterize the communication quality in the different tests (speed, antenna position and two tracks). The paper draws general conclusions on the performance of V2V-communication. The presented test results supports comparison of the tested antenna placements on the trucks and…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Investigation of Wheel Aerodynamic Resistance of Passenger Cars

SAE International Journal of Passenger Cars - Mechanical Systems

Volvo Car Corp.-Simone Sebben
Chalmers Univ. of Technology-Alexey Vdovin, Lennart Lofdahl
  • Journal Article
  • 2014-01-0606
Published 2014-04-01 by SAE International in United States
There are a number of numerical and experimental studies of the aerodynamic performance of wheels that have been published. They show that wheels and wheel-housing flows are responsible for a substantial part of the total aerodynamic drag on passenger vehicles. Previous investigations have also shown that aerodynamic resistance moment acting on rotating wheels, sometimes referred to as ventilation resistance or ventilation torque is a significant contributor to the total aerodynamic resistance of the vehicle; therefore it should not be neglected when designing the wheel-housing area.This work presents a numerical study of the wheel ventilation resistance moment and factors that affect it, using computational fluid dynamics (CFD). It is demonstrated how pressure and shear forces acting on different rotating parts of the wheel affect the ventilation torque. It is also shown how a simple change of rim design can lead to a significant decrease in power consumption of the vehicle. A way of introducing ventilation torque into the driving resistance equation is discussed.The results show that it is possible to assess ventilation resistance moment using CFD.…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Comparison of Fuel-Cut Ageing during Retardation and Fuel-Cut during Acceleration

Volvo Car Corp.-Anna Fathali, Mats Laurell, Fredrik B. Ekström, Annika Kristoffersson
Chalmers Univ. of Technology-Bengt Andersson, Louise Olsson
Published 2014-04-01 by SAE International in United States
The effect of various fuel-cut agings, on a Volvo Cars 4-cylinder gasoline engine, with bimetallic three-way catalysts (TWCs) was examined. Deactivation during retardation fuel-cut (low load) and acceleration fuel-cut (high load, e.g. gearshift or traction control) was compared to aging at λ=1. Three-way catalysts were aged on an engine bench comparing two fuel-cut strategies and their impact on of the life and performance of the catalysts. In greater detail, the catalytic activity, stability and selectivity were studied. Furthermore, the catalysts were thoroughly analyzed using light-off and oxygen storage capacity measurements. The emission conversion as a function of various lambda values and loads was also determined. Fresh and 40-hour aged samples showed that the acceleration fuel-cut was the strategy that had the highest contribution towards the total deactivation of the catalyst system. Also, the retardation fuel-cut was found to be detrimental to the catalyst system but not to the same extent as an acceleration fuel-cut. During the aging procedure, exotherms were observed at the fuel-cut and the intensity of these exotherms was increasing with the length…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Effect of Piston Bowl Shape and Swirl Ratio on Engine Heat Transfer in a Light-Duty Diesel Engine

Volvo Car Corp.-Hakan Persson, Mattias Ljungqvist
Lund Univ.-Helgi Skuli Fridriksson, Martin Tuner, Oivind Andersson, Bengt Sunden
Published 2014-04-01 by SAE International in United States
Heat transfer losses are one of the largest loss contributions in a modern internal combustion engine. The aim of this study is to evaluate the contribution of the piston bowl type and swirl ratio to heat losses and performance. A commercial CFD tool is used to carry out simulations of four different piston bowl geometries, at three engine loads with two different swirl ratios at each load point. One of the geometries is used as a reference point, where CFD results are validated with engine test data. All other bowl geometries are scaled to the same compression ratio and make use of the same fuel injection, with a variation in the spray target between cases. The results show that the baseline case, which is of a conventional diesel bowl shape, provides the best emission performance, while a more open, tapered, lip-less combustion bowl is the most thermodynamically efficient. The results also show that the response of the flow field, due to swirl variations, is not the same for all piston configurations and, therefore, the effects…
Annotation ability available