Refine Your Search

Search Results

Viewing 1 to 8 of 8
Technical Paper

Engine Test Data Quality Requirements for Model Based Calibration: A Testing and Development Efficiency Opportunity

2013-04-08
2013-01-0351
This paper documents some of the findings from a joint JLR and AVL project which was conducted at the JLR Gaydon test facility in the UK. A testing and development efficiency concept is presented and test data quality is identified as a key factor. In support of this methods are proposed to correctly measure and set targets for data quality with high confidence. An illustrative example is presented involving a Diesel passenger car calibration process which requires response surface models (RSMs) of key engine measured quantities e.g. engine-out emissions and fuel consumption. Methods are proposed that attempt to quantify the relationships between RSM statistical model quality metrics, test data variability measures and design of experiment (DOE) formulation. The methods are tested using simulated and real test data.
Technical Paper

A Pragmatic Model-Based Product Engineering Process

2014-04-01
2014-01-0308
Complexity of electronics and embedded software systems in automobiles has been increasing over the years. This necessitates the need for an effective and exhaustive development and validation process in order to deliver fault free vehicles at reduced time to market. Model-based Product Engineering (MBPE) is a new process for development and validation of embedded control software. The process is generic and defines the engineering activities to plan and assess the progress and quality of the software developed for automotive applications. The MBPE process is comprised of six levels (one design level and five verification and validation levels) ranging from the vehicle requirements phase to the start of production. The process describes the work products to be delivered during the course of product development and also aligns the delivery plan to overall vehicle development milestones.
Technical Paper

CFD Simulation of Side Glass Surface Noise Spectra for a Bluff SUV

2006-04-03
2006-01-0137
Simulation of local flow structures in the A-pillar/side glass region of bluff SUV geometries, typical of Land Rover vehicles, presents a considerable challenge. Features such as relatively tight A-pillar radii and upright windscreens produce flows that are difficult to simulate. However, the usefulness of aerodynamics simulations in the early assessment of wind noise depends particularly on the local accuracy obtained in this region. This paper extends work previously published by the author(1) with additional data and analysis. An extended review of the relevant published literature is also provided. Then the degree to which a commercial Lattice-Boltzman solver (Exa PowerFLOW™) is currently able to capture both the local flow structure and surface pressure distribution (both time averaged and unsteady) is evaluated. Influential factors in the simulation are shown to be spatial resolution, turbulence and boundary layer modelling.
Technical Paper

Recent Advances in Powertrain Sound Quality Hardware Tuning Devices and Perspectives on Future Advances

2009-05-19
2009-01-2192
Over the past decade there have been significant advances made in the technology used to engineer Powertrain Sound Quality into automobiles. These have included exhaust system technologies incorporating active and semi-active valves, intake system technologies involving passive and direct feedback devices, and technologies aimed at tuning the structure-borne content of vehicle interior sound. All of these technologies have been deployed to complement the traditional control of NVH issues through the enhancement of Powertrain Sound Quality. The aim of this paper is to provide an historical review of the recent industry-wide advances made in these technologies and to provide the author's perspective on what issues have been addressed and what opportunities have been delivered.
Technical Paper

Robust Application of CBE and OBE for Engine Testing System Diagnosis

2016-04-05
2016-01-0987
Tightening emissions regulations are driving increasing focus on both equipment and measurement capabilities in the test cell environment. Customer expectations are therefore rising with respect to data uncertainty. Key critical test cell parameters such as load, fuel rate, air flow and emission measurements are more heavily under scrutiny and require real time methods of verification over and above the traditional test cell calibration in 40CFR1065 regulation. The objective of this paper is to develop a system to use a carbon dioxide (CO2) based balance error and an oxygen (O2) based balance error for diagnosing the main measurement system error in the test cell such as fuel rate meter, air flow meter, emission sample line, pressure transducer and thermocouples. The general combustion equation is used to set up the balance equations with assumptions. To validate the air fuel ratio balance model an experimental investigation was carried out for D2 5 mode and C1 8 mode cycle test.
Journal Article

Off-Road Tire-Terrain Interaction: An Analytical Solution

2016-09-27
2016-01-8029
A novel semi-analytical solution has been developed for the calculation of the static and dynamic response of an off road tire interacting with a deformable terrain, which utilizes soil parameters independent of the size of the contact patch (size-independent). The models involved in the solution presented, can be categorized in rigid and/or pneumatic tires, with or without tread pattern. After a concise literature review of related methods, a detailed presentation of the semi-analytical solution is presented, along with assumptions and limitations. A flowchart is provided, showing the main steps of the numerical implementation, and various test cases have been examined, characterized in terms of vertical load, tire dimensions, soil properties, deformability of the tire, and tread pattern. It has been found that the proposed model can qualitatively capture the response of a rolling wheel on deformable terrain.
Journal Article

Analytical and Developmental Techniques Utilized in the Structural Optimization of a New Lightweight Diesel Engine

2015-06-15
2015-01-2298
Jaguar Land Rover (JLR) has designed and developed a new inline 4 cylinder engine family, branded Ingenium. In addition to delivering improved emissions and fuel economy over the outgoing engine, another key aim from the outset of the program was to reduce the combustion noise. This paper details the NVH development of the lead engine in this family, a 2.0 liter common rail turbo diesel. The task from the outset of this new program was to reduce the mass of the engine by 21.5 kg, whilst also improving the structural attenuation of the engine by 5 dB in comparison to the outgoing engine. Improving the structural attenuation by 5 dB was not only a key enabler in reducing combustion noise, but also helped to achieve a certified CO2 performance of 99 g/km in the all-new Jaguar XE model, by allowing more scope for increasing cylinder pressure forcing without compromising NVH.
Technical Paper

Measurement of Soot Concentration in a Prototype Multi-Hole Diesel Injector by High-Speed Color Diffused Back Illumination Technique

2017-10-08
2017-01-2255
A prototype multi-hole diesel injector operating with n-heptane fuel from a high-pressure common rail system is used in a high-pressure and high-temperature test rig capable of reaching 1100 Kelvin and 150 bar under different oxygen concentrations. A novel optical set-up capable of visualizing the soot cloud evolution in the fuel jet from 30 to 85 millimeters from the nozzle exit with the high-speed color diffused back illumination technique is used as a result of the insertion of a high-pressure window in the injector holder opposite to the frontal window of the vessel. The experiments performed in this work used one wavelength provide information about physical of the soot properties, experimental results variating the operational conditions show the reduction of soot formation with an increase in injection pressure, a reduction in ambient temperature, a reduction in oxygen concentration or a reduction in ambient density.
X