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Technical Paper

Dispersion of Test-Based NVH Characteristics at Various Trim Levels

2011-05-17
2011-01-1569
A broad measurement campaign was run at Volvo aiming at the evaluation of dispersion in test-based NVH characteristics of a car body and at the derivation of reference data for judging the accuracy of CAE predictions. Within this work 6, nominally identical, vehicles were tested. Tests included operational noise on Complete Vehicle (CV) level (road noise, engine noise and idling noise), NTF, VTF & Acoustic FRF measurements in CV, Trimmed Body (TB) & TB-Stripped (TBS) configurations. Additionally, modal analysis and NTF, VTF, AFRF tests were carried out on 4 BIPs of the same vehicle type. Further, limited tests were carried out on 28 vehicles of the same type. The aim of the work was to study the development of dispersion with increasing complexity of the test object, from the BIP to TB and CV.
Technical Paper

High-Performance Grid Computing for Cummins Vehicle Mission Simulation: Architecture and Applications

2011-09-13
2011-01-2268
This paper presents an extension of our earlier work on Cummins Vehicle Mission Simulation (VMS) software. Previously, we presented VMS as a Windows based analysis tool to simulate vehicle missions quickly and to gauge, communicate, and improve the value proposition of Cummins engines to customers. We have subsequently extended this VMS architecture to build a grid-computing platform to support high volume of simulation needs. The building block of the grid-computing version of VMS is an executable file that consists of vehicle and engine simulation models compiled using Real Time Workshop. This executable file integrates MATLAB and Simulink with Java, XML, and JDBC technologies and interacts with the MySQL database. Our grid consists of a cluster of twenty Linux servers with quad-core processors. The Sun Grid Engine software suite that administers this cluster can batch-queue and execute 80 simulations concurrently.
Technical Paper

Borderline Design of Crankshafts Based on Hybrid Simulation Technology

2009-06-15
2009-01-1918
This paper introduces different modeling approaches of crankshafts, compares the refinement levels and discusses the difference between the results of the crankshaft durability calculation methodologies. A V6 crankshaft is considered for the comparison of the refinement levels depending on the deviation between the signals such as main bearing forces and deflection angle. Although a good correlation is observed between the results in low speed range, the deviation is evident through the mid to high speed ranges. The deviation amplitude differs depending on the signal being observed and model being used. An inline 4 crankshaft is considered for the comparison of the durability results. The analysis results show that the durability potential is underestimated with a classical crankshaft calculation approach which leads to a limitation of maximum speed of 5500 rpm.
Technical Paper

Modeling, Design and Validation of an Exhaust Muffler for a Commercial Telehandler

2009-05-19
2009-01-2047
This paper describes the design, development and validation of a muffler for reducing exhaust noise from a commercial tele-handler. It also describes the procedure for modeling and optimizing the exhaust muffler along with experimental measurement for correlating the sound transmission loss (STL). The design and tuning of the tele-handler muffler was based on several factors including overall performance, cost, weight, available space, and ease of manufacturing. The analysis for predicting the STL was conducted using the commercial software LMS Virtual Lab (LMS-VL), while the experimental validation was carried out in the laboratory using the two load setup. First, in order to gain confidence in the applicability of LMS-VL, the STL of some simple expansion mufflers with and without extended inlet/outlet and perforations was considered. The STL of these mufflers were predicted using the traditional plane wave transfer matrix approach.
Journal Article

Noise Optimization of Diesel Engines with New Combustion Systems

2009-05-19
2009-01-2081
The Euro 6 emission standard requires a strong reduction of NOx and soot emissions for future Diesel engines. One of the ways to reach the Euro 6 standard for new Diesel engines is to adopt the low NOx combustion concept with new injection strategy, but this kind of combustion can give higher combustion noise and worse stability in transient conditions. This paper describes some of the new methodologies developed by Renault for controlling and optimizing Diesel combustion noise, particularly for engines with low NOx combustion modes. In steady working conditions, it was found that a homogeneous combustion mode gave high level of combustion excitation particularly in the 1000 Hz octave band. Thus improvement should be made in the engine structural attenuation (SA) in this frequency range in order to limit engine noise deterioration. This requires not only the technical solutions for improving the structural attenuation, but also reliable methods for measuring engine SA.
Technical Paper

Design and Development of a Self-Contained Engine Stand for NVH Troubleshooting and Testing of Diesel Engines

2009-05-19
2009-01-2083
Diesel engine NVH is an important characteristic of light and medium duty vehicles in today's market. Typical NVH related issues like idle gear clatter, gear whine and cab shake at low speed and load conditions are perceived as unpleasant and are unacceptable to the end customer. The root cause of many of these NVH concerns is frequently associated with powertrain structures and the excitation of different mechanical components within the engine. This paper focuses on development of robust and self-contained engine test stand which can help both for troubleshooting NVH concerns and for setting relevant targets at the subsystem levels to mitigate NVH risks. The motivation behind developing this unique test stand is given with examples and the advantages are demonstrated for relevant engine NVH testing applications.
Journal Article

Design and Analysis of a Gear Rattle Test Rig

2009-05-19
2009-01-2113
Gear rattle in manual transmission systems is a complex phenomenon and problematic to transmission and vehicle manufacturers. In the last three decades some inroads have been made in applying analytical and numerical analysis to understand rattle, however solutions and design methodologies for low rattle or no rattle are elusive. Problems with rattling transmissions continue to plague the industry. Controlled experiments for transmission rattle are required for research, to aid in the development of design tools and for validation of these tools. This paper presents a test rig which utilises a Hooke's joint to induce the torsional oscillations that lead to rattle. The design process relies on torsional lumped mass modeling and linear and transient nonlinear analyses and this paper details how the correct specification of the required driving motor isolation system is achieved.
Technical Paper

AN OPTIMAL SOLUTION THROUGH LEAN MANUFACTURING USING VALUE STREAM MAPPING TOWARDS EFFICIENT PRODUCTION FOR A WORLD- CLASS AUTOMOBILE BRAKES MANUFACTURING COMPANY

2009-12-13
2009-28-0054
Today, numerous companies have a major opportunity to reduce their costs and customer lead time and cycle time through the application of Lean Manufacturing processes. In recent years, almost every manufacturing industry has been trying to get ‘lean’. Lean thinking represents a set of principles and techniques for the identification and elimination of wastages in manufacturing and administrative processes. Value Stream Mapping (VSM) which is one of the lean manufacturing approaches has emerged as the preferred way to support and implement the lean approach. VSM is a helpful tool to identify the waste and improvement areas. VSM enables a company to see the entire process in both its current and desired future state, and develop the road map that prioritises the projects or tasks to bridge the gap between the current state and the future (lean) state.
Technical Paper

An integrated approach to extract basic Suspension Data through Integration of tri-axial spindle coupled road simulator, wheel force transducer and a wheel vector sensor.

2009-12-13
2009-28-0027
In a highly competitive global as well as the domestic market of the passenger car industry, the search for the complete car is on the forefront. With such a situation, carmakers are experimenting with innovative technology on various development programs to cater the needs of the customer. This paper shows one such experimentation to extract the basic suspension Kinematics & Compliance data with the integration of a Tri-axial Spindle Coupled road load simulator, a wheel force transducer and a Wheel Vector Sensor in absence of expensive Suspension Parameters Measuring Machine (SPMM).
Technical Paper

PERFORMANCE OF GEROTOR OIL PUMP FOR AN AUTOMOTIVE ENGINE - PREDICTION USING CFD ANALYSIS AND EXPERIMENTAL VALIDATION

2009-12-13
2009-28-0007
The reduction of development time of new Internal Combustion Engines prototype and reduction of fuel consumption are key issues in automotive Industry. Lubricating oil pump systems having potential of reducing fuel consumption by up to 3% in the new European Motor Vehicle Emission Group (MVEG) Cycle. Oil pump feeds lubricant oil into the parts of engine to prevent wear and to cool the moving parts of the engine. Gerotor pump is a special kind of internal rotary positive displacement pump which is driven by crank shaft. It provides high volumetric efficiency and smooth pumping action, and it works well with a wide range of fluid viscosities. Tip to tip clearance, volumetric efficiency, flow ripple and cavitation damage are causes for concern in Gerotor pump with high output flow. To optimize the pump performance, it is essential to understand the flow dynamics inside the pump.
Technical Paper

Process Simulation Integration in Product Design

2009-01-21
2009-26-0089
The effect of processing parameters on the material properties is an important design consideration in plastic part design. The process may cause anisotropic properties due to matrix and fiber orientation, develop internal stresses during cooling, cause thickness variation etc. These effects if not considered in the product design and analysis, may result in premature product failure, reduced safety factor, fit and finish issues or higher costs and weight due to over design. Injection molded long glass polypropylene and blow molded PC/ABS have been used in automotive structural parts requiring to meet stringent static and dynamic loads as per the regulatory legislation. This paper demonstrates the use of injection molding and blow molding process simulation to incorporate the process effect on material and structure properties.
Technical Paper

Control System Development for Retrofit Automated Manual Transmissions

2009-12-13
2009-28-0001
For transmission suppliers tooled primarily for producing manual transmissions, retrofitting a manual transmission with actuators and a controller is business viable. It offers a low cost convenience for the consumer without losing fuel economy when compared to torque converter type automatics. For heavy duty truck fleets even the estimated 3% gain in fuel economy that the Automated Manual Transmission (AMT) offers over the manual transmission can result in lower operational costs. This paper provides a case study using a light duty transmission retrofitted with electric actuation for gears and the clutch. A high level description of the control algorithms and hardware is included. Clutch control is the most significant component of the AMT controller and it is addressed in detail during operations such as vehicle launch from rest, launch from coast and launch on grades.
Technical Paper

The Thought Process for Developing Sound Package Treatments for a Vehicle

2011-05-17
2011-01-1679
This paper discusses the thought process that one needs to go through for developing an appropriate sound package treatment for a vehicle. In the development process one needs to put proper emphasis on understanding the source, path, and the receiver system. One needs to have an understanding on how to reduce the noise at the source, path, and/or receiver location. One may need to conduct a feasibility study of the benefits of various noise control options. In terms of sound package treatments one needs to understand the fundamentals of acoustical materials how they work and why one material performs differently than another one, as well as the importance of a well documented specification that every supplier has to meet.
Technical Paper

Development and Testing of an Advanced Extended Range Electric Vehicle

2011-04-12
2011-01-0913
The focus of this paper is the design, implementation, and initial testing of a plug-in hybrid electric vehicle drivetrain in a 2009 GM compact SUV base vehicle by the University of Victoria's EcoCAR Team. The Team is using a condensed three-year vehicle development process modeled after those used by Tier 1 automotive manufactures, and mandated by the competition rules of EcoCAR: The NeXt Challenge. During the first year of the competition, intensive research was performed to identify a powertrain architecture that would give the best overall performance based on greenhouse gas emissions, criteria air contaminant emissions, fuel economy, petroleum use, and vehicle performance according to the weighting formulas of the competition. As a result, an extended range electric vehicle utilizing GM's Two-Mode transmission, a large lithium-ion battery pack, and a rear traction motor was selected; these components were integrated into the vehicle in the second year of the competition.
Technical Paper

Process Automation Wizard for Vehicle Dynamics Applications

2011-04-12
2011-01-0740
The imperative to get to the market faster with new and better products, has determined all automotive OEM to rethink their product development cycle, and, as a result, many hardware based processes were replaced and/or augmented with virtual, software based ones. However, the virtualization itself does not guaranties better and faster products. In the area of vehicle dynamics, we concentrate on improving the multi-body model development process, facilitating comprehensive virtual testing, and verifying the robustness of the design. The authors present a highly flexible and efficient environment that encourages, enforces, and facilitates model sharing, reusing of components, and parallelization of vehicle dynamics simulations, developed on top of an existing commercial off-the-shelf engineering software application.
Technical Paper

Development of Transient Simulation Methodologies for Underhood Hot Spot Analysis of a Truck

2011-04-12
2011-01-0651
This paper presents the efforts done by Volvo 3P, through a partnership with ThermoAnalytics Inc, to develop transient thermal simulation methodologies of the under hood of a truck. The verification process for the hot spots analysis currently in use at Volvo 3P is described and the key transient situations for the hot spots analysis are identified: hot shutdown, DPF regeneration and long drive cycle, are currently only covered by physical testing late in the project, contrary to steady-state operating conditions that are already managed through simulations in the early stage of the development phase. The goal of this work is to develop simulation methodologies for these transient situations which are likely to increase the efficiency of the verification process. The key issues to be satisfied are to minimize the model development and the simulation times while achieving an acceptable accuracy level.
Technical Paper

NVH Development of EU5 2.0L and 2.2L Diesel Engine

2011-04-12
2011-01-0932
There is higher and higher demand by customers for vehicles with the maximum level of comfort, this aspect being a target to be achieved together with the general trend to increase performance and also with the necessity to reduce engine out emissions to satisfy the new environmental regulations. GMDAT has recently developed new EU5 2.0 and 2.2 liter L4-cylinder turbocharged Diesel engines that, to address customer demands, have improved power, lower exhaust gas emissions and NVH performance aligned to best in class in its segment. With the final aim of making this engine best in class from an NVH perspective, the NVH development has been executed in a very structured way, going through target setting and deployment, concept and design, combustion and mechanical development through computational analysis first and subsequently experimental tests.
Technical Paper

Development of Low Cost Vehicle Concept for United States Using Systems Engineering Principles

2011-04-12
2011-01-1019
The paper presents a development strategy for a Low Cost Vehicle (LCV) concept set at a target MSRP of $8000 (USD) for the U.S. market. Tata Nano, currently the world's cheapest car in production, is developed on similar principles of the Ford's Model T concept. This paper adopts a similar methodology behind the development of the Tata Nano and is considered as the starting point for the LCV development. It gives an overview of the unique product development process of the ‘Tata Nano’ and shows the possibility of applying similar methodologies, based on systems engineering principles, for future low cost vehicles which will be suitable for the American market. The major automotive systems were assigned specific cost targets based on the set target cost of $8000 (USD) for the LCV. The specifications of the systems were derived based on customer needs and the U.S.
Technical Paper

Transmission Algorithm Development using System Simulation (Virtual Vehicle)

2011-04-12
2011-01-1233
Due to the multitude of external design constraints, such as increasing fuel economy standards, and the increasing number of global vehicle programs, developers of automotive transmission controls have had to cope with increasing levels of system complexity while at the same time being forced by the marketplace to improve system quality, reduce development costs, and improve time to market. General Motors Powertrain (GMPT) chose to meet these challenges through General Motors Company's Road-to-Lab-to-Math (RLM) strategy, particularly the Math-based method of a virtual vehicle simulation environment called System Simulation. The use of System Simulation to develop transmission control algorithms has enabled GMPT to improve product quality and reduce development times and costs associated with the dependence on physical prototypes. Additionally, System Simulation has facilitated the reuse of GMPT controls development assets, improving overall controls development efficiency.
Journal Article

A Structured Approach for Function Analysis of Complex Automotive Systems

2011-04-12
2011-01-1268
Function analysis provides the backbone of systems engineering design and underpins the use of Design for Six Sigma and Failure Mode Avoidance tools. Identification and management of interfaces is a key task in systems engineering design, in ensuring that the system achieves its functions in a robust and reliable way. The aim of the work presented in this paper was to develop and implement a structured approach for function analysis of a complex system, which focuses on the identification and characterization of interfaces. The proposed approach is based on the principle of separation of the functional and physical domains and development of function decomposition through iteration between functional and physical domains. This is achieved by integrating some existing / known engineering tools such as Boundary Diagram, State Flow Diagram, Function Tree and an enhanced interface analysis within a coherent flow of information.
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