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Technical Paper

Zero Resistance Technology (ZRT)

Delphi's Zero Resistance Technology (ZRT) is a revolutionary new product/process that enables the reduction of mass and volume from a traditional wiring assembly. ZRT is defined as a minimal (zero) resistance change over time. The ZRT product is an electrical/electronic connection system which provides a viable solution for high density and limited space wiring applications. The ZRT process is a semi-automated wiring harness manufacturing system with flexibility to produce harnesses to the customer demand.
Technical Paper

Use of CFD Simulation to Predict Fan Power and Airflow Pattern Inside the Climatic Chamber

For A/C and cooling systems development is usual send vehicles to US or Europe for wind tunnel tests, witch is expensive and has a long lead-time. Here in Brazil Delphi has at the Piracicaba Technical Center a chamber equipped with temperature control and chassis dynamometer. There is a up-grade project for it that consist in add ducts with fans inside the chamber that will get air from the chamber, already in the right temperature, accelerate and homogenate the air flow and blow it out direct to the front end of the vehicle. For development purposes may be possible eliminate totally the necessity of sending vehicle abroad. It was then decided to use CFD simulation to predict firstly the required fan power necessary to supply winds until 120 km/h at the front end of the vehicle and secondly predict the airflow pattern inside the chamber, considering chamber inlet air, chamber outlet air, exhaust outlet, duct outlet and flow pattern around the vehicle.
Technical Paper

Transient Simulation of DGI Engine Injector with Needle Movement

Utilization of direct injection systems is one of the most promising technologies for fuel economy improvement for SI engine powered passenger cars. Engine performance is essentially influenced by the characteristics of the injection equipment. This paper will present CFD analyses of a swirl type GDI injector carried out with the Multiphase Module of AVL's FIRE/SWIFT CFD code. The simulations considered three phases (liquid fuel, fuel vapor, air) and mesh movement. Thus the transient behavior of the injector can be observed. The flow phenomena known from measurement and shown by previous simulation work [2, 7, 10, 11] were reproduced. In particular the simulations shown in this paper could explain the cause for the outstanding atomization characteristics of the swirl type injector, which are caused by cavitation in the nozzle hole.
Technical Paper

The Solution for Steady State Temperature Distribution in Monolithic Catalytic Converters

This paper presents a simplified thermal model for round catalytic converters in steady state operation. Using this model, the analytic solution for the temperature distribution in the monolithic substrate is obtained. This analytic solution in the substrate is, then, combined with those in the intumescent mat [1] and the metal shell to obtain the temperature profile in the radial direction of the converter except for three unknown temperatures at the three material interfaces, which can be solved using an Excel application program. This analytical temperature solution facilitates the studies of the effects of various design parameters such as the exhaust gas temperature, exhaust gas flow rate, substrate cell geometry, converter dimensions, and ambient temperature and flow, etc.
Technical Paper

The Effect of Changes in Ambient and Coolant Radiator Inlet Temperatures and Coolant Flowrate on Specific Dissipation

In this paper, a theoretical model for the calculation of Specific Dissipation (SD) was developed. Based on the model, the effect of ambient and coolant radiator inlet temperatures on SD has been predicted. Results indicate that the effect of ambient and coolant inlet temperature variation on SD is small (less than 2%) when ambient temperature varies between 10 and 50°C and coolant radiator inlet temperature between 60 and 120°C. The effect of coolant flowrate on SD is larger if there is a larger flowrate variation. Experimental results indicate that a 1 % variation at 1.0 L/s will cause about ±0.6% SD variation. Therefore the flowrate should be carefully controlled.
Technical Paper

The Assembly Deformation and Pressure of Stuffed Catalytic Converter Accounting for the Hysteresis Behavior of Pressure vs Density Curve of the Intumescent Mat

Accurately predicting converter assembly deformation and mat pressure is essential in converter packaging design and manufacturing. In stuffing packaging, the annulus between the deformed shell and the catalyst is larger than that between the stuffing cone and the catalyst. As a result, the mat expands and undergoes unloading process. Tests show that the mat exhibits different loading and unloading characteristics. Using such a hysteresis mat pressure vs density curve in finite element analysis, the computed converter deformations closely agree with test data. Conversly, neglecting the mat hysteresis behavior may overestimate the deformation and pressure by a factor of three to four.
Technical Paper

System Modeling of A Damper Module

A recent trend within the automotive industry has been an emphasis on the development of modular assemblies for future vehicle applications. This trend has created a need for the development of methods to predict the performance of modules within the vehicle environment. In particular, the development of system models that account for the interactions between components within a modular assembly is necessary to insure that a module is properly designed. This paper describes a finite element system model of a damper module as installed in a McPherson strut front suspension. The modeling techniques used to construct the components within the modular assembly are discussed. The results of a study of the structural behavior of a damper module model subjected to quasi-static loading conditions are presented. Additionally, the effects of changes in individual component specifications on the overall system response are considered and the results are displayed.
Technical Paper

Solid Oxide Fuel Cell Auxiliary Power Unit - A Paradigm Shift in Electric Supply for Transportation

Delphi Automotive Systems and BMW have been jointly developing Solid Oxide Fuel Cell (SOFC) technology for application in the transportation industry primarily as an on-board Auxiliary Power Unit (APU). In the first application of this joint program, the APU will be used to power an electric air conditioning system without the need for operating the vehicle engine. The SOFC-based APU technology has the potential to provide a paradigm shift in the supply of electric power for passenger cars. Furthermore, supplementing the conventional fuel with reformate in the internal combustion engine, extremely low emissions and high system efficiencies are possible. This is consistent with the increasing power demands in automobiles in the new era of more comfort and safety along with environmental friendliness.
Technical Paper

Solid Oxide Fuel Cell Auxiliary Power Unit - A Development Update

Delphi Automotive Systems and BMW are jointly developing Solid Oxide Fuel Cell (SOFC) technology for application in the transportation industry primarily as an on-board Auxiliary Power Unit (APU). In the first application of this joint program, the APU will be used to power an electric air conditioning system without the need for operating the vehicle engine. The SOFC based APU technology has the potential to provide a paradigm shift in the supply of electric power for passenger cars. Furthermore, by supplementing the conventional fuel with reformate in the internal combustion engine, extremely low emissions and high system efficiencies are possible. This is consistent with the increasing power demands in automobiles in the new era of more comfort and safety along with environmental friendliness. Delphi Automotive Systems and BMW were successful in demonstrating an Auxiliary Power Unit (APU) based on Solid Oxide Fuel Cell (SOFC) technology in February, 2001.
Journal Article

Solder Void Modeling and Its Influence on Thermal Characteristics of MOSFETs in Automotive Electronics Module

Current generation automobiles are controlled by electronic modules for performing various functions. These electronic modules have numerous semiconductor devices mounted on printed circuit boards. Solders are generally used as thermal interface material between surface mount devices and printed circuit boards (PCB) for efficient heat transfer. In the manufacturing stage, voids are formed in solders during reflow process due to outgassing phenomenon. The presence of these voids in solder for power packages with exposed pads impedes heat flow and can increase the device temperature. Therefore it is imperative to understand the effect of solder voids on thermal characteristics of semiconductor devices. But the solder void pattern will vary drastically during mass manufacturing. Replicating the exact solder void pattern and doing detail simulation to predict the device temperature for each manufactured module is not practical.
Technical Paper

Six Sigma: Behind The Scenes

Although the Six Sigma [1] concept has become very popular in industrial sectors, very little is said about how to start a successful implementation in a Corporation, or when it should be initiated, and the most important, who should be addressed to lead this task. Its methodologies are widely observed by different sectors of the automotive market, typically focusing in projects with a potential financial impact, following the DMAIC sequence. More than just financial return, this sophisticated tool, has a direct impact on Quality in different levels for both non-productive process and manufacturing process, that eventually would also affect some organizational structures that ultimately can be understood as reengineering.
Technical Paper

Resistance Welding for Automotive Wiring Harness Connection - Small Gauge Cables

Miniaturization is an important trend in many technology segments, once it can enable innovative applications generating new markets. This trend was begun in electronics industry after World War II and has spawned changes into automotive sector also. For Automotive Wiring Harness, miniaturization is clearly presented in most of the components, mainly because of its benefits like the potential of mass reduction, cost reduction and efficiency improvement. Furthermore the main voice of customer points to cable gauge reduction that represents a considerable challenge for connection manufacturing process due to quality control limitations presented by conventional crimp process for 0,35 [mm₂] cables and smaller. According to that, the scope of this article is to present, in details, a manufacturing process optimization for an alternative and more robust technology of joining copper stranded cables to tin brass terminals used on automotive wiring harness, Resistance Welding.
Journal Article

Real-time Sensing of Particulate Matter in a Vehicle Exhaust System

Onboard diagnostic regulations require performance monitoring of diesel particulate filters used in vehicle aftertreatment systems. Delphi has developed a particulate matter (PM) sensor to perform this function. The objective of this sensor is to monitor the soot (PM) concentration in the exhaust downstream of the diesel particulate filter which provides a means to calculate filter efficiency. The particulate matter sensor monitors the deposition of soot on its internal sensing element by measuring the resistance of the deposit. Correlations are established between the soot resistance and soot mass deposited on the sensing element. Currently, the sensor provides the time interval between sensor regeneration cycles, which, with the knowledge of the exhaust gas flow parameters, is correlated to the average soot concentration.
Technical Paper

Powertrains of the Future: Reducing the Impact of Transportation on the Environment

Tomorrow's winning powertrain solutions reside in those technology combinations providing optimized propulsion systems with zero emissions and no cost or performance penalty compared with today's vehicles. The recent Kyoto Protocol for CO2 reduction and the California Air Resources Board (CARB) thrust for zero emission vehicles along with the European Regulatory community, motivate car manufacturers to adopt new light body structures with low aerodynamic drag coefficients, low-rolling resistance and the highest efficiency powertrains. The environmental equation expresses car manufacturers aptitude and desire to create zero emission vehicles at acceptable levels of performance unlike limited range electrical powered vehicle products. The cheapest solution to the environmental equation remains the conventional internal combustion engine ($30 to $50 per kW).
Technical Paper

Optimization of Oxygen Sensor

Optimization of the mechanical aspects of a heated conical oxygen sensor for desired performances, such as low heater power, good poison resistance, fast light-off, and broad temperature range, etc. was achieved with computer modeling. CFD analysis was used to model the flow field in and around a sensor in an exhaust pipe to predict the convection coefficients, poisoning, and switching time. Heat transfer analysis coupled with electrical heating was applied to predict temperature and light-off time. Results of the optimization are illustrated, with good agreements between modeling and testing.
Technical Paper

Non-Linear Dynamic Analysis of a SuperPlug™ Door Module Response to a Door Slam Event

The SuperPlug™ door module is a new Delphi innovation. It is a one-piece composite structure, which integrates several door components into one assembly. This reduces the total part count, simplifies the vehicle level assembly process, and reduces labor cost (see the Appendix). The door slam durability test is an important factor in door module design. As more hardware is integrated into the SuperPlug, this subsystem performance in a door slam test becomes important. Therefore, the correct placement of components and the supporting structure is critical. Currently, the evaluation of door slam durability for the SuperPlug is a process of build then test. This is time consuming and costly due to a long testing lead-time and the expense of tooling a new mold. It was realized that a numerical process for assessing the effect of door slam would be required. This process would compute the dynamic response using finite element analysis (FEA).
Technical Paper

Modal Participation Analysis for Identifying Brake Squeal Mechanism

Brake squeal phenomenon often involves modal coupling between various component modes. In order to reduce or eliminate squeal, it is very important to understand the coupling mechanism so that the key component(s) can be modified accordingly. This paper demonstrates a quantitative method to define system mode shapes using the concept of modal participation factors. This method is implemented on a front disc brake system to identify the modal coupling mechanism associated with its high frequency squeal. Complex eigenvalue analysis is carried out and the squeal frequency is correlated. System mode shapes are then processed with an in-house program to calculate modal participation factors based on a complex MAC (Modal Assurance Criteria) algorithm. The coupling mechanism is identified and possible countermeasures are discussed.
Technical Paper

Mean Value Engine Modelling of an SI Engine with EGR

Mean Value Engine Models (MVEMs) are simplified, dynamic engine models which are physically based. Such models are useful for control studies, for engine control system analysis and for model based engine control systems. Very few published MVEMs have included the effects of Exhaust Gas Recirculation (EGR). The purpose of this paper is to present a modified MVEM which includes EGR in a physical way. It has been tested using newly developed, very fast manifold pressure, manifold temperature, port and EGR mass flow sensors. Reasonable agreement has been obtained on an experiemental engine, mounted on a dynamometer.
Technical Paper

Laser Welding: An Exploratory Study towards Continuous Improvement on Stainless Steel Welding Joints

The utilization of Laser welding process has increased during last years in several areas of industry, due to many benefits that can be achieved with this technology, such as: flexibility, productivity and quality. Thus, the optimization of Laser welding processes has been considered as a “green field” to be explored by Laser manufacturers, automation companies and process/project engineers. Nowadays there are few researches that provide a roadmap for Laser welding processes improvement that approaches both the aspects and characteristics applied to evaluate the Laser weld application performance. Therefore, this paper has per its main purpose through an exploratory study to provide parameters toward continuous improvement of Laser welding process considering both types of Lasers: Laser spot weld and Laser seam weld of stainless steel joints, thus this work may be considered as theoretical and practical reference to be applied by people involved with Laser welding applications.
Technical Paper

LIN Bus and its Potential for Use in Distributed Multiplex Applications

The increasing features and complexity of today's automotive architectures are becoming increasingly difficult to manage. Each new innovation typically requires additional mechanical actuators and associated electrical controllers. The sheer number of black boxes and wiring are being limited not by features or cost but by the inability to physically assemble them into a vehicle. A new architecture is required which will support the ability to add new features but also enable the Vehicle Assembly Plants to easily assemble and test each subsystem. One such architecture is a distributed multiplex arrangement that reduces the number of wires while enabling flexibility and expandability. Previous versions have had to deal with issues such as noise immunity at high switching currents. The LIN Bus with its low cost and rail-to-rail capability may be the key enabling technology to make the multiplexed architecture a reality.