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Technical Paper

Pressure Amplitude Influence on Pulsating Exhaust Flow Energy Utilization

2018-04-03
2018-01-0972
Abstract A turbocharged Diesel engine for heavy-duty on-road vehicle applications employs a compact exhaust manifold to satisfy transient torque and packaging requirements. The small exhaust manifold volume increases the unsteadiness of the flow to the turbine. The turbine therefore operates over a wider flow range, which is not optimal as radial turbines have narrow peak efficiency zone. This lower efficiency is compensated to some extent by the higher energy content of the unsteady exhaust flow compared to steady flow conditions. This paper experimentally investigates the relationship between exhaust energy utilization and available energy at the turbine inlet at different degrees of unsteady flow. A special exhaust manifold has been constructed which enables the internal volume of the manifold to be increased. The larger volume reduces the exhaust pulse amplitude and brings the operating condition for the turbine closer to steady-flow.
Technical Paper

Development of 80- and 100- Mile Work Day Cycles Representative of Commercial Pickup and Delivery Operation

2018-04-03
2018-01-1192
Abstract When developing and designing new technology for integrated vehicle systems deployment, standard cycles have long existed for chassis dynamometer testing and tuning of the powertrain. However, to this day with recent developments and advancements in plug-in hybrid and battery electric vehicle technology, no true “work day” cycles exist with which to tune and measure energy storage control and thermal management systems. To address these issues and in support of development of a range-extended pickup and delivery Class 6 commercial vehicle, researchers at the National Renewable Energy Laboratory in collaboration with Cummins analyzed 78,000 days of operational data captured from more than 260 vehicles operating across the United States to characterize the typical daily performance requirements associated with Class 6 commercial pickup and delivery operation.
Technical Paper

Numerical and Experimental Research on Flow Resistance of Cool Medium from Heat Dissipation System for Construction Vehicles

2018-04-03
2018-01-0088
Abstract Construction vehicles own some inherent characteristics, such as low velocity, high power and following heavy heat flux et al. Aiming at decreasing flow resistance and managing airflow, a 39 ton single drum road roller from one of the biggest manufactures in China was employed as a research target to seek out the effect of air flow resistance on the performance of its heat dissipation system. For a start, a simplified 3D model of the road roller in a virtual wind tunnel was established with a commercial software, which was pre-processed in Gambit later. The radiators were set with heat exchanger boundary condition based on the analysis on the air-side elementary unit, as for the cooling fan, the experimental results in the wind tunnel were transformed into the corresponding boundary condition.
Technical Paper

Prediction of Wear Loss of Exhaust Valve Seat of Gasoline Engine Based on Rig Test Result

2018-04-03
2018-01-0984
Abstract The purpose of the present research was to predict, from the results of rig test, the amount of wear on exhaust valve seats in durability testing of gasoline engines. In the rig test, measurements were made of the wear loss ratios in a number of cases in which a number of factors in valve seat wear were within a certain range. The results for factors of high sensitivity were further used to create an equation for calculating the amount of wear. The amounts of wear calculated from the equation for calculating the amount of wear and from driving modes of actual engines were found from the results to show a high correlation with the amount of wear in bench tests and the amount of wear in vehicle tests. The influence of differing valve seat materials and valve diameters was also determined by rig test, indicating that the amount of wear in actual engines could be estimated.
Technical Paper

Accident Reconstruction with Data Recorded by Electronic Control Units in Vehicles with a Pre-crash Safety System

2018-04-03
2018-01-1440
Abstract Data recorded by vehicle-mounted electronic control units (ECUs) are highly useful in traffic accident reconstruction. In this context, event data recorders (EDRs) are airbag ECU components used to log information from crash events, typically providing data on speed, accelerator operation, RPMs and brake lamp activation for a period of around 5 s before a collision. Information on accelerator/brake lamp operation is very useful in understanding pre-crash driver actions, but the accuracy of EDR speed data must be checked in this regard. Such data are unlikely to reflect actual speed during brake-related skidding, for example, as they are determined from the rotational speed of the drive train. Thus, it is important to check the accuracy of EDR speed data in accident reconstruction. Meanwhile, pre-crash safety systems (PCSs) are also becoming more widespread in automobile usage today.
Technical Paper

Study on Correlation between After-Treatment Performance and Running Conditions, Exhaust Parameters of Heavy-Duty Diesel Vehicle

2018-04-03
2018-01-0338
Abstract The increasingly stringent emission regulations have mandated the use of CCRT (catalyzed continuously regeneration trap) made by upstream DOC (diesel oxidation catalyst) and downstream CDPF (catalyzed diesel particulate filter) for heavy-duty diesel vehicles, which is proved to be the only way that can efficiently control the gaseous and particulate emissions. The performance of after-treatment is greatly influenced by the running conditions of the diesel vehicle and its exhaust parameters, so this paper intended to use grey relational analysis to study the correlation between running conditions (velocity, acceleration, VSP (vehicle specific power)), exhaust parameters (exhaust flow rate, DOC inlet temperature, concentrations of CO, THC, O2 and NOX) and the performance of DOC and CCRT based on chassis dynamometer test. Results showed that the effect of DOC on CO and THC is mainly affected by exhaust flow rate, exhaust temperature and THC concentration.
Technical Paper

Optimization Design of Rear-Engine Bus Cooling System Based on 1D/3D Coupling Simulation

2018-04-03
2018-01-0771
Abstract This study investigated the effects of underhood structure parameters (two types of air ducts, two types of inlet grilles and the opening angle of inlet grilles) on the cooling characteristics of the rear-engine bus; then, the optimum design scheme of the underhood was determined. The air-side resistance load of the cooling system, which is based on fan performance, was selected as the optimization objective. Simulations were created based on a porous media model and standard a k-ε model. The next step was to build a 1D/3D coupling simulation to utilize the advantages of 1D simulation’s fast convergence speed and 3D simulation’s extensive research range. Besides, the use of 1D/3D coupling simulation can efficiently avoid the errors of simulation results which arise from the non-uniform airflow on the cooling module. Results show that the airflow rate of the rectangular air duct increased by 7 to 11percent.
Technical Paper

Heavy Duty Diesel Engine Modeling with Layered Artificial Neural Network Structures

2018-04-03
2018-01-0870
Abstract In order to meet emissions and power requirements, modern engine design has evolved in complexity and control. The cost and time restraints of calibration and testing of various control strategies have made virtual testing environments increasingly popular. Using Hardware-in-the-Loop (HiL), Volvo Penta has built a virtual test rig named VIRTEC for efficient engine testing, using a model simulating a fully instrumented engine. This paper presents an innovative Artificial Neural Network (ANN) based model for engine simulations in HiL environment. The engine model, herein called Artificial Neural Network Engine (ANN-E), was built for D8-600 hp Volvo Penta engine, and directly implemented in the VIRTEC system. ANN-E uses a combination of feedforward and recursive ANNs, processing 7 actuator signals from the engine management system (EMS) to provide 30 output signals.
Technical Paper

Achieving Fast Catalyst Light-Off from a Heavy-Duty Stoichiometric Natural Gas Engine Capable of 0.02 g/bhp-hr NOX Emissions

2018-04-03
2018-01-1136
Abstract Recently conducted work has been funded by the California Air Resources Board (CARB) to explore the feasibility of achieving 0.02 g/bhp-hr NOX emissions for heavy-duty on-road engines. In addition to NOX emissions, greenhouse gas (GHG), CO2 and methane emissions regulations from heavy-duty engines are also becoming more stringent. To achieve low cold-start NOX and methane emissions, the exhaust aftertreatment must be brought up to temperature quickly while keeping proper air-fuel ratio control; however, a balance between catalyst light-off and fuel penalty must be addressed to meet future CO2 emissions regulations. This paper details the work executed to improve catalyst light-off for a natural gas engine with a close-coupled and an underfloor three-way-catalyst while meeting an FTP NOX emission target of 0.02 g/bhp-hr and minimizing any fuel penalty.
Technical Paper

Improvement in Selective Catalytic Reduction Model Accuracy for Predicting NOx Conversion at High Temperature

2018-04-03
2018-01-0346
Abstract As a result of WNTE regulations and the introduction of close-coupled aftertreatment systems, exhaust purification at high temperatures in commercial vehicles has become increasingly important in recent years. In this report, we improve the prediction accuracy for NOx conversion at high temperatures in the kinetic model of conventional Cu-selective catalytic reduction (Cu-SCR). Reaction rate analysis indicated that the rate of NH3 oxidation was extremely low compared to the rate of standard SCR. We found that NOx concentration-dependent NH3 oxidations (termed NOx-assisted NH3 oxidations) were key to the rate of NH3 oxidation. The output of the improved Cu-SCR kinetic model was in agreed with experimental results obtained from the synthetic gas bench and engine dynamometer bench. We analyzed the contribution of each reaction to NH3 consumption during Cu-SCR. Under NH3 + NO + O2, standard SCR was dominant at low temperature.
Technical Paper

Identification of Gear Shift Quality as a Key Attribute in Commercial Vehicle Development

2017-11-27
2017-01-7011
Abstract Indian automotive market has grown extremely competitive in the recent past. In order to meet the ever growing expectations of the customers, automobile manufacturers are compelled to offer their products under superior quality with supreme comfort. Customers wish of high levels of tactile comfort in the cabin compartment and effortless operation of peripherals will result in negligible fatigue and a pleasant drive, needs to be duly fulfilled. One has to focus more on Gear shift lever and Steering wheel, which are being the most sensitive tactile points in an automobile. The gear shift lever knob is frequently used and significantly influences the perception of the shift comfort for a driver during actual vehicle application.
Technical Paper

Association of Impact Velocity with Serious-Injury and Fatality Risks to Cyclists in Commercial Truck-Cyclist Accidents

2017-11-13
2017-22-0013
This study aimed to clarify the relationship between truck–cyclist collision impact velocity and the serious-injury and fatality risks to cyclists, and to investigate the effects of road type and driving scenario on the frequency of cyclist fatalities due to collisions with vehicles. We used micro and macro truck–cyclist collision data from the Japanese Institute for Traffic Accident Research and Data Analysis (ITARDA) database. We classified vehicle type into five categories: heavy-duty trucks (gross vehicle weight [GVW] ≥11 × 103 kg [11 tons (t)], medium-duty trucks (5 × 103 kg [5 t] ≤ GVW < 11 × 103 kg [11 t]), light-duty trucks (GVW <5 × 103 kg [5 t]), box vans, and sedans. The fatality risk was ≤5% for light-duty trucks, box vans, and sedans at impact velocities ≤40 km/h and for medium-duty trucks at impact velocities ≤30 km/h. The fatality risk was 6% for heavy-duty trucks at impact velocities ≤10 km/h.
Technical Paper

Method for Preventing Contamination on Trucks Cabin Side Using CFD

2017-11-07
2017-36-0080
Abstract Although ignored by most people not directly involved with highway and off-road commercial trucks operation the accumulation of dust and mud on cabin side can become a rather annoying issue. Besides adhering to the passengers clothes dirt contamination may also compromise driver visibility constituting a safety concern. For a truck manufacturer it can revert into quality complaints and negatively influence customers’ future buying decisions. In this context, fascia air deflectors are common devices used in truck industry to control the airflow over the cabin panels and ultimately prevent contamination deposition. This paper presents a methodology to avoid dust and mud accumulation on commercial trucks cabin doors based on the predicted airflow field by computational fluid dynamics (CFD) and a reference flow metric defined through a simple bench test.
Technical Paper

Factors that Impact on Tire Structure Useful Life

2017-11-07
2017-36-0121
Abstract This work describes a statistic analysis of the service life of tires applied in off-highway trucks used in open-pit mining. Understanding the process of occurrence of structural failures, correlated to the fatigue mechanism and often observed in mechanic components, is of vital importance for the current industry. Since these failures usually happen suddenly, understanding them in the most diverse components submitted to cyclic loads helps analyzing the material’s progressive deterioration along time; it acts as a return to potential improvements in the product, giving feedback of computing simulation data; and it potentially increases operational safety by mitigating the consequences it has on the productive process and on the people exposed to such failures. The tires, components that integrate great part of the on wheels vehicles fleet - amongst them: transportation equipment, industrial mobile equipment and mining equipment - are inserted in this context.
Technical Paper

Development of a Commercial Truck Parabolic Leaf Spring Using CAE Simulation with Correlated Experimental Stress Analysis Results

2017-11-07
2017-36-0126
Abstract The development costs that new design requires are subject to everyday discussions and saving opportunities are mandatory. Using CAE to predict design changes can avoid excessive costs with prototypes parts, considering the high reliability those current mathematical models can provide. This paper presents the methodology used during the development of a parabolic leaf spring for the rear suspension of a commercial truck, considering mainly the parabolic profiles and stress distribution on the leaves, calculated using CAE software (ANSYS) and experimental tests to measure the actual stress on each leaf, certifying the correlation between computational calculations and real stress on the parts during bench and vehicle evaluations.
Technical Paper

Vehicle Integration, Gear Material and Heat Treatment Effects on Rear Axle Whining Noise

2017-11-07
2017-36-0129
Abstract This paper will focus whining noise on rear axles applied in mid-size trucks. Vehicle integration changes during development affect directly the gear noise perception, in which it may be intensified. Also, gear material and heat treatment choices for the rear axle need to be done carefully, taking into consideration the integration changes and also the driver usage. A lessons learned collection over the diverse aspects of a rear axle whining noise will be the basis of this paper.
Technical Paper

Improve Frame Assembly Flexibility with Low Investment

2017-11-07
2017-36-0132
Abstract Commercial vehicles are being developed for long decades in Brazil creating a deep background on manufacturing process. With the current scenario a variety of different vehicles specifications (weight capacity, load distribution, torque, size, etc.) are being required by the market. Joints with bolts and nuts are the engineering solution for the most of the problems found in automotive engineering regarding commercial vehicles. Screw processes were made during the last 150 years. Nowadays current frame modifications on aftermarket are made with arc weld process that affects directly the material properties and the process needs to be performed by critical personal with training and capacity. In addition cost and timing does not fit for the best equation on how to proceed with the modifications. The solution proposed brings more flexibility on frame assemblies that can be extended to other products.
Technical Paper

On Road Truck Fuel Consumption Measurements in Real Conditions of Application and Speeds up to 90 km/h, Performed by a Towing Trailer with Electromagnetic Brake

2017-11-07
2017-36-0109
Abstract Environmental damage and climate change, air pollution, energy efficiency, fuel consumption and emissions are subjects for studies and legislations worldwide. Brazil must therefore be prepared to follow global trends in energy optimization tests and developments, including Euro 6 equivalent emission legislation. Considering the worldwide tendency for Real Driving Condition Test for heavy vehicles, the authors, using the developed Towing Trailer Prototype provided with an electromagnetic brake, performed fuel consumption on-road tests. For measuring fuel consumption on-road or on testing tracks, the developed system allows initially measurements with an independent auxiliary tank for short distances and measurement with an auxiliary tank connected with the truck tank for long distances. The tests were performed on road in real conditions initially by maximum speeds of 75 km/h.
Technical Paper

Power Cell Unit (PCU) for Modern HDD Engines

2017-11-07
2017-36-0301
Abstract Governmental legislation with regards to emissions is an important driver for Heavy Duty Diesel (HDD) engine developments. To reach the targets, in most of cases it is necessary to increase the thermal-mechanical loads, increasing the level of technical demand for the engine components. Besides that, other important aspects drive the engine development, as the cost of ownership, demanding for instance an extended oil draining interval, which leads to harsher environment for the engine components. In order to cope with the modern engine demands, this article presents a piston and piston rings specially designed to meet these targets in a robust way. Starting with the ring pack, CrN based coatings applied by PVD (Physical Vapor Deposition) are commonly applied to top ring face to reach durability targets.
Technical Paper

Supplier Base Optimization on MWM MAR-I Diesel Engines Launch

2017-11-07
2017-36-0139
Abstract Due to the introduction of PROCONVE MAR-I emission regulation, the Brazilian automotive industry developed Diesel engines to comply with this legislation demanding new components to automotive supplier base. However, at the same time this industrial sector was facing a difficult financial situation caused mainly by the crisis that impacted Brazil in last years. In 2015, around 27 local suppliers filed for bankruptcy affecting the whole Automotive Supply Chain. This scenario already represents a problem for current products established in market, but it represents a major challenge for new launches. This paper will discuss how MWM Motores Diesel made sourcing decisions and manage to develop components and suppliers in this harsh scenario, also looking for the supplier base optimization.
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