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The SI engine combustion model LI-CFM introduced by Boudier et, al. (1992) [8] is extended to deal with actual engines. New models are proposed to simulate ignition with convection at the spark and flame-wall interaction. The scalar properties of the unburnt gases within the combustion zone are computed. This allows for the computation of flame propagation in temperature, fuel and residual gas stratified charges. A model for NO and CO formation is introduced. It is based on a conditional burnt/unburnt averaging of the reaction rates. Pollutants are created at the flamelet level and evolve in the burnt, gases using a mixed equilibrium/kinetic scheme. All these physical models are implemented in a multi-block version of the Kiva 2 code, KMB. This code is used to simulate a 4-valve engine including intake ports. Initial and boundary conditions are obtained from a ID acoustic code.

The fuel injection in internal combustion engines plays a crucial role in the mixture formation, combustion process and pollutants' emission. Its correct modeling is fundamental to the prediction of an engine performance through a computational fluid dynamics simulation. In the first part of this work a tridimensional numerical simulation of a multi-hole’s injector, using ethanol as fuel, is presented. The numerical simulation results were compared to experimental data from a fuel spray injection bench test in a quiescent vessel. The break up model applied to the simulation was the combined Kelvin-Helmholtz Rayleigh-Taylor, and a sensitivity analysis of the liquid fuel penetration curve, as well on the overall spray shape was performed according to the model constants. Experimental spray images were used to aid the model tuning. The final configuration of the KH-RT model constants that showed best agreement with the measured spray was C3 equal to 0.5, B1, 7 and Cb, 0.

Recently the analysis of air-fuel mixing and combustion has become important under the stringent emissions regulations of diesel engines. In the case of gasoline engines, the KIVA computer program has been developed and used for the analysis of combustion. In this paper, the calculations of combustion phenomena in DI diesel engines are performed by modifying the KIVA program so as to be applicable to multi-hole nozzles and arbitrary patterns of injection rate. The thermophysical and ther-mochemical properties of gasoline are altered to those diesel fuel. In order to investigate the ability of this modified program, the calculations are compared with the experiments on single cylinder engines concerning the pressure, flame temperature and mass change of chemical species in cylinders. Furthermore, the calculation for the heavy duty DI diesel engine is performed with this diesel combustion program.

The main objective of this paper is to investigate the performance of partial filtration DPF substrates using 3-D Computational Fluid Dynamics (CFD) methods. Detailed 3-D CFD simulations were performed for real world sizes of DPF inlet and outlet channel geometries. Two concepts of partial filters were studied. The baseline geometry was a standard DPF with the front plugs removed. The second concept was to eliminate half of outlet plugs in addition to the inlet plugs to improve the pressure drop performance. The total filter efficiency was defined in current study to quantify the overall filter filtration efficiency which combines the effects from wall flow efficiency and flow through efficiency. For baseline case, 45% of total exhaust gas was found to go through the inlet channels, and the total trap efficiency was as high as 60%. However, only a 10% pressure loss reduction was found due to the removal of the outlet channel plugs from the DPF inlet side.

Diesel Particulate Filters (DPF) are widely used to meet 2007 and beyond EPA Particulate Matter (PM) emissions requirements. During the soot loading process, soot is collected inside a porous wall and eventually forms a soot cake layer on the surface of the DPF inlet channel walls. A densely packaged soot layer and reduced pore size due to Particulate Matter (PM) deposition will reduce overall DPF wall permeability which results in increasing pressure drop across the DPF substrate. A regeneration process needs to be enacted to burn out all the soot collected inside the DPF. Soot mass is not always evenly distributed as the distribution is affected by the flow and temperature distribution at the DPF inlet. As a result, the heat release which is determined by the burn rate is locally dependent. High temperature gradients are often found inside DPF substrate as a result of these locally dependent burn rates.

The present study deals with the reduction of fluid vibrations by dissipating the kinetic energy in a closed vibrating container partly filled using vertical slotted obstacles. The effect of the barriers on the liquid vibration inside a closed container exposed to a harmonic excitation is numerically studied. A single vertical slotted barrier (SVSB) and multivertical slotted barrier (MVSB) systems are considered for different liquid levels. The 3D liquid domain with the tank and the barrier as boundaries is modelled and solved numerically using ANSYS-CFX software. The reduction in pressures on the walls and the ceiling of the tank due to the influences of the slot size and numbers were evaluated to optimize the size and the numbers of the slots. The numerical approach shows an ability to simulate the nonlinear behavior of the liquid vibration when using vertical slotted barriers (VSB).

A 3D PDF add-on is available to complement and enhance Theorem’s CATIA V5 to Creo View visualization product, part of the company’s Visualize 3D range.

Three-component Particle Image Velocimetry (3D PIV) is a fluid velocity measurement technique that has evolved from the laboratory to become a method appropriate for use in large-scale wind tunnel testing. An example application of 3D PIV in a wind tunnel test is described. The PIV technique was applied to characterize the wake of The Ground Transportation System (GTS) model developed for the Department of Energy (DOE) Heavy Vehicle Drag Reduction (HVDR) program. The test was performed in the Ames/Army 7×10 foot wind tunnel. The objective of the PIV measurements was to validate the HVDR computational fluid dynamics code. The PIV method and PIV system are described. Sample truck wake data with and without boattail attachments are shown. 3D PIV system successfully captured the effects of the boattails on the truck wake.

3D Printing is a revolutionizing technology extensively used in automotive and aerospace industries. It is an additive layer manufacturing process by which a scale model is quickly fabricated from CAD data in just a matter of hours. In Automotive trims, 3D Printing technology is a boon. It is used: To simulate the ‘tooled up/production part’ in terms of assembly, defined function, limited CMF and fit & finish. To evaluate and capture early feedback from top management with respect to aesthetic, design, etc. For early prediction and plan of action towards improvement for craftsmanship. To reduce design iterations, interface concerns, product lifecycle time and cost. In this paper, we will discuss on the technical aspects of how the trims 3D printed models have been effectively put to use. We have covered case studies under door trims, floor console, tail gate trim, glove box latch, molded spare wheel cover, Instrumental panel duct and bumper mask-painting template.

Dimensional Management (DM) is a methodology to predict and control the impact of variation on assembly from, fit, and function. Application of Dimensional Management tools and other modeling and simulation techniques are combined in a process called 3D Re-Engineering for application to existing production designs. Analytical techniques for predicting the impact of variation on assembly fit, and corresponding methods for controlling variation are presented, as used in a production environment for root cause corrective action on existing assembly fit problems. Assembly variation analysis is typically performed early in the product development phases, by coordinating datums, assembly sequences, assembly methods, and detail part tolerances across the product development team.

Abstract Real-time reconstruction of 3D environment attributed with semantic information is significant for a variety of applications, such as obstacle detection, traffic scene comprehension and autonomous navigation. The current approaches to achieve it are mainly using stereo vision, Structure from Motion (SfM) or mobile LiDAR sensors. Each of these approaches has its own limitation, stereo vision has high computational cost, SfM needs accurate calibration between a sequences of images, and the onboard LiDAR sensor can only provide sparse points without color information. This paper describes a novel method for traffic scene semantic segmentation by combining sparse LiDAR point cloud (e.g. from Velodyne scans), with monocular color image. The key novelty of the method is the semantic coupling of stereoscopic point cloud with color lattice from camera image labelled through a Convolutional Neural Network (CNN).

The vehicle Heating, Ventilation and Air conditioning (HVAC) system is designed to meet both the safety and thermal comfort requirements of the passengers inside the cabin. The thermal comfort requirement, however, is highly subjective and is usually met objectively by carrying out time dependent mapping of parameters like the velocity and temperature at various in-cabin locations. These target parameters are simulated for the vehicle interior for a case of hot soaking and its subsequent cool-down to test the efficacy of the AC system. Typically, AC performance is judged by air temperature at passenger locations, thermal comfort estimation along with time to reach comfortable condition for human. Simulating long transient vehicle cabin for thermal comfort evaluation is computationally expensive and involves complex cabin material modelling.

In automotive FEA analysis, there are many components or assemblies which can be simplified to two-dimensional (2D) plane or axisymmetric analytical problems instead of three-dimensional (3D) simulation models for quick modeling and efficient analysis to meet the timing in the design development process, especially in the advanced design phase and iteration studies. Even though some situations are not perfectly planar or axisymmetric problems, they may still be approximated in 2D planar or axisymmetric models, achieving results accurate enough to meet engineering requirements. In this paper, the authors have presented and summarized several complex 3D analytical situations which can be replaced by simplified plane axisymmetric models or 2D plane strain analytical models.

To ensure reliable Diesel Particulate Filter (DPF) regeneration, even in critical situations such as slow city driving, a fuel vaporizer can be used to introduce additional hydrocarbons directly into the Diesel aftertreatment system. The fuel vaporizer provides significantly shorter reaction times than possible with engine measures alone and also helps minimize the extensive engine measures normally required to achieve the DPF ignition temperatures. As with other components, correctly optimizing complex aftertreatment systems requires not simply characterizing and optimizing an individual component, but also understanding the interaction between components and the behaviour of the system as a whole. The value of a system simulation lies in rapid turnaround times combined with the ability to address three-dimensional phenomena, since they often have a decisive impact on the system performance (e.g., the hydrocarbon distribution and its associated catalytic heat release).

Steady induction port flow has been simulated in a complex configuration, which is modelled on a four-valve engine with a pent-roof chamber. The numerical solution has been obtained using a finite volume method coupled with the standard k - ε turbulence model. It is shown that the 3D flow field is characterised by large vortices with horizontal axes induced by the inlet jets, and by flow interaction between inlet jets from both valves. Special attention has been paid to flow distributions in the valve curtain areas. Velocity and turbulence energy profiles have been obtained in these areas and compared with previous hot-wire measurements and 2D calculations using Reynolds stress models as well as the k - ε model. The findings in this study are expected to enhance our understanding of complex engine induction port flows and to provide better boundary conditions for in-cylinder flow calculations

A novel CFD simulation technique has been developed that unites realistic three-dimensional resolution of diesel particulate filter systems with computational efficiency. Three-dimensional resolution of the thermofluiddynamic behaviour during transient soot loading and regeneration is necessary for the optimization of the function, durability, weight and cost of DPF systems. Computational efficiency is required to allow its use as a standard development tool during all engineering phases and to allow the simulation of driving cycles. The detailed conclusions that can be drawn about soot distribution and thermal characteristics during the regeneration assist in ensuring the DPF function and avoiding DPF failures over the operational lifetime.

The present work addresses the possibility to correctly simulate Partial Homogeneous Charge Compression Ignition (PHCCI) combustion, obtained by the application of EGR up to 60% without using detailed kinetic models. In particular, the laminar and turbulent time characteristic model has been analyzed and improved. The study illustrates the prediction capabilities that can be achieved with such an approach. The paper reports the results obtained from the simulation of a single cylinder research engine and a four-cylinder diesel engine to verify the validity of the proposed method independently of engine geometry and configuration. All numerical results are compared with experimental pressure traces and rates of heat release, as well as with NOx and soot emissions over a wide range of operating conditions. With the modified characteristic time model, realistic simulations of engine combustion up to EGR values of about 60% have been obtained for both engines.

The present paper reports the results of the numerical simulations carried out by means of a modified version of the KIVA-3V code and of the comparison with experimental results obtained by using different optical techniques in a single-cylinder optically accessible diesel engine. The engine is equipped with a commercial four valves cylinder head and a second-generation, Common-Rail injection system. A detailed kinetic model consisting of 283 reactions involving 69 species is applied to simulate the combustion process and the soot and NOx formation. The fuel surrogate model consisting of two constituent components, n-heptane and toluene, approximating the physical and ignition properties of the diesel oil, is considered. The Partially Stirred Reactor (PaSR) assumption is adopted to maintain the computational cost within acceptable limits.

This paper aims to validate chemical kinetic mechanisms of surrogate gasoline three components fuel by calculating one-dimensional laminar burning velocity of iso-octane/air mixture. Next, the application of level-set method on premixed combustion without consideration the effect of turbulence eddies on flame front is also studied in three-dimensional computational fluid dynamic (3D-CFD) simulation. In the 3D CFD simulation, there is an option to calculate laminar burning velocity by using empirical correlations, however it is applicable only for particular initial pressure and temperature in spark ignition engine cases. One-dimensional burning velocities from lean to rich of iso-octane/air mixture are calculated by using CHEMKIN-PRO with detailed chemistry and transport phenomena as a function of different equivalence ratios, different unburnt temperature and pressure ranges.

To develop injection nozzles and to improve the numerical simulation technology of fuel spray, a measuring technology to analyze the process of disintegration into droplets accurately is required. Performances required by a spray droplets measuring device are: “ability to measure in the combustion condition inside the engine cylinder”, “ability to measure the diameter of spray droplets in high-density fields”, “ability to measure the structure of spray droplets in 3D”, and an improved measuring accuracy of non-spherical droplets. These elements are required in order to analyze the spray droplets structure of gasoline direct injection engines. As a promising method to satisfy these requirements, the laser holography method has been already suggested. However, it has some drawbacks, such as a difficulty in measuring spray droplets in high-density fields and over a long analysis period.