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Technical Paper

Engine Fault Detection Using Vibration Signal Reconstruction in the Crank-Angle Domain

2011-05-17
2011-01-1660
Advanced engine test methods incorporate several different sensing and signal processing techniques for identifying and locating manufacturing or assembly defects of an engine. A successful engine test method therefore, requires advanced signal processing techniques. This paper introduces a novel signal processing technique to successfully detect a faulty internal combustion engine in a quantitative manner. Accelerometers are mounted on the cylinder head and lug surfaces while vibration signals are recorded during engine operation. Using the engine's cam angular position, the vibration signals are transformed from the time domain to the crank-angle domain. At the heart of the transformation lies interpolation. In this paper, linear, cubic spline and sinc interpolation methods are demonstrated for reconstructing vibration signals in the crank-angle domain.
Technical Paper

Comparisons of Global Drive-By Noise Regulations and Levels for Medium and Heavy Duty Trucks

2011-05-17
2011-01-1612
As North American truck manufactures have entered the global market it has become apparent that there are widely varying drive-by noise regulations required in various areas of the world. This paper will describe differences between various test procedures, track layouts, and required levels. Data will be presented showing vehicle results from various procedures, used to quantify differences in noise levels between a range of procedures. Countries were ranked from least restrictive to most restrictive based on test procedures and legal market requirements.
Technical Paper

Noise Benchmarking of the Detroit Diesel DD15 Engine

2011-05-17
2011-01-1566
Several new or significantly upgraded heavy duty truck engines are being introduced in the North American market. One important aspect of these new or revised engines is their noise characteristics. This paper describes the noise related characteristics of the new DD15 engine, and compares them to other competitive heavy truck engines. DD15 engine features relevant to noise include a rear gear train, isolated oil pan and valve cover, and an amplified high pressure common rail fuel system. The transition between non-amplified and amplified common rail operation is shown to have a significant noise impact, not unlike the transition between pilot injection and single shot injection in some other engines.
Technical Paper

Finite Element Analysis of Light Vehicle Cab's Hydraulic Mount Based on Fluid-Structure Interaction Method

2011-05-17
2011-01-1604
Hyperelastic model constants of rubber material are predicted based on test date. The fluid-structure interaction model of light vehicle cab's hydraulic mount is established. Static characteristics of the hydraulic mount are analyzed by quasi-static method. In dynamic characteristics analysis, the flow model of fluid is set to turbulent K-Epsilon RNG. The dynamic stiffness and loss angle of the hydraulic mount are presented via the finite element model. The simulations of static and dynamic characteristics agree well with corresponding test results. The effects of main structure parameters to the dynamic characteristics of the hydraulic mount are analyzed based on the finite element model.
Technical Paper

Derivation of the Force Interaction within Strongly Coupled Systems - Application to Diesel Engine Oil Pumps

2011-05-17
2011-01-1531
Due to the increasing focus on noise and vibration for future vehicles, there is a need for a clear definition of the requirements between vehicle manufacturers and auxiliary suppliers. Auxiliary characterisations are also needed as input for structure-borne numerical prediction models. Strongly coupled systems are amongst the most difficult structure-borne noise issues, as the transmitted forces and powers are strongly dependent upon the mobilities of both the vibration source and receiver. The so-called “blocked forces” can be used as intrinsic source descriptions. The challenge is then to design auxiliary test benches perfectly rigid in the frequency range of interest. The current paper is based on the French research program MACOVAM dedicated to the vibro-acoustic characterisation of oil pumps for truck engines. An original test bench was designed to measure quasi-blocked forces over the [150 Hz-2800 Hz] frequency range.
Technical Paper

A Hybrid Combustion Control Strategy for Heavy Duty Diesel Engines Based on the Technologies of Multi-Pulse Injections, Variable Boost Pressure and Retarded Intake Valve Closing Timing

2011-04-12
2011-01-1382
Combustion control strategy for high efficiency and low emissions in a heavy duty (H D) diesel engine was investigated experimentally in a single cylinder test engine with a common rail fuel system, EGR (Exhaust Gas Recirculation) system, boost system and retarded intake valve closing timing actuator. For the operation loads of IMEPg (Gross Indicated Mean Effective Pressure) less than 1.1 MPa the low temperature combustion (LTC) with high rate of EGR was applied. The fuel injection modes of either single injection or multi-pulse injections, boost pressure and retarded intake valve closing timing (RIVCT) were also coupled with the engine operation condition loads for high efficiency and low emissions. A higher boost pressure played an important role in improving fuel efficiency and obtaining ultra-low soot and NOx emissions.
Journal Article

Effects of Post-Injection Strategies on Near-Injector Over-Lean Mixtures and Unburned Hydrocarbon Emission in a Heavy-Duty Optical Diesel Engine

2011-04-12
2011-01-1383
Post-injection strategies aimed at reducing engine-out emissions of unburned hydrocarbons (UHC) were investigated in an optical heavy-duty diesel engine operating at a low-load, low-temperature combustion (LTC) condition with high dilution (12.7% intake oxygen) where UHC emissions are problematic. Exhaust gas measurements showed that a carefully selected post injection reduced engine-out load-specific UHC emissions by 20% compared to operation with a single injection in the same load range. High-speed in-cylinder chemiluminescence imaging revealed that without a post injection, most of the chemiluminescence emission occurs close to the bowl wall, with no significant chemiluminescence signal within 27 mm of the injector. Previous studies have shown that over-leaning in this near-injector region after the end of injection causes the local equivalence ratio to fall below the ignitability limit.
Technical Paper

Vibro-Acoustic Source-Path-Receiver approach to Identifying and Troubleshooting in an Agricultural Tractor Mode Coupling Issue

2011-05-17
2011-01-1730
As an agricultural tractor OEM was moving a new tractor model from development into production, an objectionable cab “boom” was identified that was not present in the preproduction pilot -level tractors. The cab boom was identified as a low frequency tone causing an increase of 7 (dBA) over the level in the pilot tractors, which was deemed unacceptable. The process used by the tractor OEM engineering team to address this problem has been widely used and refined in the automotive industry, but it is relatively new in the agricultural/off-road vehicle industry. This paper describes the source-path-receiver approach that led to identifying the exhaust tip as the source and the vibro-acoustic coupling of a windshield structural mode with an acoustic cab cavity mode as the path of the boom event.
Technical Paper

Case Study of Pass-By Noise Development on a Class 8 Truck

2011-05-17
2011-01-1731
Governmental regulations regarding exterior noise emitted by motor vehicles vary throughout the world. A vehicle which is compliant in one market may not be compliant in another market. In this case, a production North American class 8 truck was being prepared for sale overseas. The requirement to meet European Union (EU) pass-by regulations as tested per the EU standard meant development of a production feasible package to substantially reduce noise emissions without changing any fundamental design or operating parameters of the truck. The development testing was done on a chassis dynamometer in a hemi-anechoic chamber without any specific pass-by noise simulation software. Efforts to develop a reasonably accurate correlation from lab to track, use of acoustic beamforming for source localization and package design iterations leading to a final successful package are discussed.
Technical Paper

Future Emission Concepts versus Fuel Quality Aspects - Challenges and Technical Concepts

2011-08-30
2011-01-2097
From current point of view future emission legislations for heavy-duty engines as well as industrial engines will require complex engine internal measures in combination with sophisticated aftertreatment systems as well as according control strategies to reach the emission targets. With EU VI, JP 09/NLT and US10 for heavy-duty engines as well as future Tier4 final or stage IV emission legislation for industrial applications, EGR + DPF + SCR probably will be combined for most applications and therefore quite similar technological approaches will be followed up in Europe as well as in the US and in Japan. Most “emerging markets” all over the world follow up the European, US or Japanese emission legislation with a certain time delay. Therefore similar technologies need to be introduced in these markets in the future. On the other hand specific market boundary conditions and requirements have to be considered for the development of tailored system concepts in these markets.
Technical Paper

Field Test of Semi-permanent use of Engines and Lube Oil with Almost No Wear and with Constant Thermal Efficiency

2011-08-30
2011-01-2113
A new type of lube oil cleaning system is successfully developed for semi-permanent use of oil by always keeping oil clean with the result of no oil change and no waste oil. It is in practical use in many marine diesel engines and in some other fields. In recent years, possibility of semi-permanent use of engines themselves has been expected based on the field data. A ship test for 7 years has verified the expected semi-permanent use of engines with almost no wear and constant thermal efficiency during the test. We present the characteristics of the oil cleaning system and the result of the test. Also, a new type of fuel oil cleaning system is presented which is useful for cleaning low quality fuel oil. As a whole, this test is the beginning of the new stage of our work following the semi-permanent use of lube oil, which has been verified and established in many diesel engines since the 1980s.
Journal Article

Investigation of Wear in Heavy Duty Diesel Engines: Part I - Use of Radioactive Tracer Technology

2011-08-30
2011-01-2114
This paper is first in a series of papers designed to investigate wear processes in modern heavy duty diesel engines. The objective of the series is to discuss the effects that engine drive cycle, lubricant formulations and in-service ageing of lubricants have on wear of critical engine components. In this paper, the Radioactive Tracer Technology technique was used to study the steady state wear behavior of a number of contacting surfaces in a Caterpillar 1P engine, as a function of the drive cycle. A test protocol consisting of 7 modes or stages was used to simulate a variety of drive cycles. The results from this work provide useful insights into the wear behavior of these surfaces under a variety of speed and load conditions.
Technical Paper

Transient Behavior of VOCs Emission and Particle Size Distribution during Active Regeneration of Diesel Particulate Filter Equipped Diesel Engine

2011-08-30
2011-01-2087
In order to reduce fine particle emission, a diesel particulate filter (DPF) has begun to be equipped to a diesel engine. During regeneration of DPF, nanoparticles are known to be formed downstream of DPF. VOCs emission during regeneration is of interest in view of toxicity and formation mechanism of nanoparticles. A heavy duty diesel engine equipped with DPF was investigated to measure particle and VOCs emissions using PTR-TOFMS (Proton Transfer Reaction - Time of Flight Mass Spectrometer). PTR-TOFMS is a new on-line mass spectrometer using chemical ionization and its application to engine exhaust measurements is new. During active regeneration of the DPF, fine particle emission was increased by nucleation. But VOCs as well as THC emissions increased prior to particle increase. After the regeneration the particle and VOCs emissions decreased immediately to the level of normal operation.
Technical Paper

Modeling of Diesel Engine Components for Model-Based Control (First Report): The construction and validation of a model of the Air Intake System

2011-08-30
2011-01-2066
Model based control design is an important method for optimizing engine operating conditions so as to simultaneously improve engines' thermal efficiency and emission profiles. Modeling of intake system that includes an intake throttle valve, an EGR valve and a variable geometry turbocharger was constructed based on conservation laws combined with maps. Calculated results were examined the predictive accuracy of fresh charge mass flow, EGR rate and boost pressure.
Technical Paper

LNG-Fuelled Engines and Fuel Systems for Medium-Speed Engines in Maritime Applications

2011-08-30
2011-01-1998
The maritime transportation sector is facing new international restrictions on exhaust emissions. NOx and SOx emissions from traditional marine fuels are a major challenge, which make natural gas a promising new clean alternative. Since the late 1980s, new concepts for medium-speed natural gas-fuelled engines have been developed, primarily for stationary power generation. This technology is currently entering the mobile sector, where Spark Ignition engines, Dual-Fuel engines and High Pressure Gas engines offer advantages such as high efficiency, low emissions and fuel flexibility. The availability of liquefied natural gas (LNG) is increasing, not least via small-scale distribution systems. In Norway, 23 coastal traffic vessels operate on LNG supplied by a distribution system that also supplies city bus fleets. This paper discusses the development of natural gas engines and fuel system technology, and describes experiences from LNG-fuelled ships in operation in Norway.
Technical Paper

Reducing Throttle Losses Using Variable Geometry Turbine (VGT) in a Heavy-Duty Spark-Ignited Natural Gas Engine

2011-08-30
2011-01-2022
Abstract Stoichiometric operation of Spark Ignited (SI) Heavy Duty Natural Gas (HDNG) engines with a three way catalyst results in very low emissions however they suffer from bad gas-exchange efficiency due to use of throttle which results in high throttling losses. Variable Geometry Turbine (VGT) is a good practice to reduce throttling losses in a certain operating region of the engine. VTG technology is extensively used in diesel engines; it is very much ignored in gasoline engines however it is possible and advantageous to be used on HDNG engine due to their relatively low exhaust gas temperature. Exhaust gas temperatures in HDNG engines are low enough (lower than 760 degree Celsius) and tolerable for VGT material. Traditionally HDNG are equipped with a turbocharger with waste-gate but it is easy and simple to replace the by-pass turbocharger with a well-matched VGT.
Technical Paper

The technical implementation of a retrofit hydrogen PFI system on a passenger car

2011-08-30
2011-01-2004
The chicken or the egg dilemma is an often used metaphor to explain the problem where car manufacturers are not eager to produce hydrogen cars since there are no hydrogen fueling stations. Petrochemical companies on the other side, do not want to invest in hydrogen fueling stations for there are no cars to fuel. Many proposals have been made to overcome this predicament, for example starting the implementation of the hydrogen economy with early markets such as public busses that run on hydrogen, because they can use a centralized fueling infrastructure and thereby reduce initial costs. However, another way to address this stalemate is by avoiding the dependency on hydrogen fueling infrastructure. This can be achieved by using flex-fuel vehicles that can run on hydrogen as well as on gasoline and/or compressed natural gas.
Technical Paper

Analysis of Numerical Simulation on Reducing Drag of Van Body Truck

2011-09-13
2011-01-2286
With the crisis of energy becoming more severity, the research of cutting down the drag of commercial vehicles is more and more important. In this work, to reduce the drag of a van body truck, aerodynamic drag reduction designs are carried out by the method of numerical simulation. Plates are fixed on the aft-body with different angle of declination. The effects of reducing drag are studied and the mechanism is discussed. The paper selects four rear add-on devices with different obliquity by 5deg, 10deg, 15deg and 20deg. Seen from the results of numerical simulation, the rear add-on device can reduce the drag effectively. The CFD simulations indicate that addition of the flat plates reduces the drag about 5∼8%. When the declination angle is 15deg, the effect is the best and the drag of the truck model is reduced by 8.9% comparing with the configuration without add-on device. This work can offer important references for the optimize design of van body truck.
Journal Article

Drag Reduction of a Modern Straight Truck

2011-09-13
2011-01-2283
A wind tunnel test program was conducted at the Langley Full Scale Tunnel (LFST) to evaluate the performance of five passive drag reduction configurations on a modern straight truck at full scale. Configurations were tested in a build-up fashion with results representing a cumulative effect. Tested configurations include a front valance, a front box fairing, a boat-tail, an ideal side-skirt, and a practical side-skirt. Configurations were evaluated over a nominal 9 degree yaw sweep to establish wind averaged drag coefficients using SAE J1252. Genuine replicate yaw sweeps were used in an uncertainty analysis. Results show up to 28% improvement in wind-averaged drag coefficient and that significant gains can be made in straight truck fuel economy, even at non-highway speeds.
Technical Paper

Failure Mode and Effects Analysis (FMEA): A Comparison Between VDA-Approach Versus QS-9000

2011-09-13
2011-01-2280
The Failure Mode and Effects Analysis is a quality method used by the automotive industry to ensure perfect quality of products before an introduction into mass production. Two industry standards are established on the market: on the one hand the approach by VDA (in German: Verband der Automobilindustrie) on the other hand the method according to QS-9000. If somebody is familiar with one method, working with the other one will result in misunderstanding and communication problems. Both standards do have the same principal ambition but the execution is totally different as common word definitions like “Function, Failure Modes, Effects and Causes” are interpreted differently. As a consequence information can be found in different columns of the chosen format sheet. For a better understanding of the two approaches the existing case study shown by VDA will be taken as an example to describe the equivalent steps according to QS-9000.
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