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Technical Paper

Implementation of Electrified Air Conditioning on a Class 8 Long Haul Vehicle

2018-04-03
2018-01-0061
Current methods employing electrified air conditioning (A/C) in class 8 long haul vehicles are hampered by insufficient capacity to cool the entire cabin both in sleeper mode and during normal on the road operation. A highly efficient single system solution is needed that meets cooling requirements under all operational modes without exceeding the power requirements that an onboard battery system can support. Results presented in this paper demonstrate the ability of an electrified A/C system to exceed cabin pulldown requirements within onboard electrical power availability while also meeting the low power draw requirements of sleeper mode operation. Results also demonstrate power electronics technology has advanced to the point that delivering ~5 kW of power at 48VDC (i.e. ~100A) can be accomplished in a reasonable sized package for commercial vehicle applications.
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
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

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

2018-04-03
2018-01-0338
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

Correlation and Verification of a Tractor Cab Model Using Statistical Energy Analysis

2018-04-03
2018-01-0142
A model of a tractor cab was built using Statistical Energy Analysis (SEA) best practices. In this paper, it is shown how this model was correlated using p/Q transfer functions measured in the lab with a volume velocity source. After correlation, the model was excited using acoustic loads measured during tractor operation. It was found that the data predicted by the model is in good agreement with the data measured inside the cabin during this test. It was concluded that SEA can be used as an engineering tool to predict the behavior under many different conditions and can be used to guide the development process.
Technical Paper

Parameters Analysis of on-Center Handling for Articulated Trucks

2018-04-03
2018-01-0136
On-center handling is one of the most important test conditions which are used to evaluate the handling performance of both passenger cars and commercial vehicles. This paper aims at investigating and verifying the influence of parameters on on-center handling of articulated trucks. A full vehicle model, including the steering system, suspension system, cab, frame, trailer and so on, was established in first by measuring the parameters of each component. The comparison of simulation and test results shown that the simulation precision of the vehicle model was up to 80%. Based on the model, the influence analysis of parameters, such as stiffness of steering drag link, steering ratio, kingpin friction, were carried out and were verified through the handling test. The analysis results indicated that larger stiffness of steering drag link, smaller gear ratio could enhance the steer sensitivity and steer stiffness, small kingpin friction is beneficial to the steering return ability.
Technical Paper

Steering Column Slip Endurance Test & Rig Development

2018-04-03
2018-01-0125
In the emerging commercial vehicle sector, it is very essential to give a product to customer, which is very reliable and less prone to the failures to make the product successful in the market. In order to make it possible, the product is to be validated to replicate the exact field conditions, where it is going to be operated. Lab testing plays a vital role in reproducing the field conditions in order to reduce the lead time in overall product life cycle development process. This paper deals with the design and fabrication of the steering column slip endurance test rig. This rig is capable of generating wear on the steering column splines coating which predominantly leads to failure of steering column. The data acquired from Proving Ground (PG) was analyzed and block cycles were generated with help of data analyzing tools.
Technical Paper

Study of Hydraulic Steering Process for Intelligent Autonomous Articulated Vehicle

2018-04-03
2018-01-0133
Intelligent autonomous articulated vehicles (IAAVs), the most important transportations of intelligent mining system, are the future direction of mining industry. Though it could realize the unmanned drive, without supports of hydraulic steering process analyses and vehicle dynamic researches, there are no references for the IAAVs to adjust the steering angle in certain driving error. It still has to check the signal from the angle sensor repeatedly to track the planned path in the working process, which lead to the low control accuracy. In this paper, the theories of hydraulic steering process and vehicle model will be developed for the vehicle intelligent control with the analyses of road and tire characteristics based on the principle of least resistance.
Technical Paper

Improving Ride Comfort of a Heavy Truck

2018-04-03
2018-01-0135
Ride comfort is simply defined as the vibration performance of the vehicle which is excited by road surface roughness, generally as the vehicle moves at specific constant velocity over the road profile. Ride comfort was an important index for heavy truck, due to long distance transfer and long time driving. In order to improve the ride comfort of a heavy truck, a detailed model, including flex frame, chassis suspension, cab suspension, powertrain, etc., was built and assembled by MSC.ADAMS software. Simulation and testing data were consistent very well, which showed the correctness of the model. The optimization of chassis and cab suspension including the stiffness of the leafspring, the damping of the shock absorber, etc. was carried out to improve the ride comfort of the vehicle. The ride comfort testing was carried out on the proving ground to verify the effectiveness the optimization results. The testing results shows that the ride comfort has been improved after tuning.
Technical Paper

Deriving the Validation Protocol for Isolator Switches Used in Commercial Vehicles

2018-04-03
2018-01-0128
All automotive components undergo stringent testing protocol during the design validation phase. Nevertheless, there are certain components in the field which are seldom captured during design validation. One of these components is the battery isolator switch. This project aims at optimizing a validation methodology for this component based on field usage and conditions. The isolator switch is the main control switch which connects and disconnects the electrical loads from the battery. This switch is used in the electrical circuit of the vehicle to prevent unwanted draining of battery when it is not needed and when the vehicle is in switched off. An electrical version of this switch uses electromagnetic coils to short the contacts. The failure mode being investigated is a high current load causing the input and output terminal to be welded.
Technical Paper

A Numerical Study on the Sensitivity of Soot and NOx Formation to the Operating Conditions in Heavy Duty Engines

2018-04-03
2018-01-0177
In this paper, computation fluid dynamics (CFD) simulations are employed to describe the effect of flow parameters on the formation of soot and NOx in a heavy duty engine under low load and high load. The complexity of diesel combustion, specially when soot, NOx and other emissions are of interest, requires using a detailed chemical mechanism to have a correct estimation of temperature and species distribution. In this work, Multiple Representative Interactive Flamelets (MRIF) method is employed to describe the chemical reactions, ignition, flame propagation and emissions in the engine. A phenomenological model for soot formation, including soot nucleation, coagulation and oxidation with O2 and OH is incorporated into the flamelet combustion model. Different strategies for modelling NOx are chosen to take into account the longer time scale for NOx formation. The numerical results are compared with experimental data to show the validity of the model for the cases under study.
Technical Paper

CFD Study of Low Soot Spray Combustionin a Heavy-Duty Diesel Engine

2018-04-03
2018-01-0186
This CFD study focuses on the influence of the nozzle diameter on the mixing process and the soot formation and oxidation process in a heavy-duty diesel engine. The CFD simulation is based on the Reynolds Averaged Navier-Stokes approach. The engine set-up is similar to an experimental case that showed rather low soot emission. The aim of the paper is to improve the understanding of the physics of the mixing process in a real engine environment with the attention to scrutinize its effect of fuel injection on combustion and soot emission. Two non-reacting cases with different injector nozzle diameters but constant injection pressure and their corresponding reacting cases are simulated with dynamic mesh motion and fuel spray modeling. The influence of injections on the mixing, combustion and emissions is analyzed and the simulation results are compared with the measurement data.
Technical Paper

Polypropylene Copolymer Automotive Canopy Plastic Structure Application

2018-04-03
2018-01-0157
This paper describes modified polypropylene copolymer (PPCP) material for canopy plastic structure in a modular commercial passenger vehicle. This compounded PPCP material has optimized flow behavior, tensile strength, modulus, impact strength, and thermal properties to meet the functional requirements. Material described in this paper is a PPCP compound reinforced with glass fiber and mica filler. The application described in this paper is a canopy plastic structure, which is a structural exterior plastic part. Canopy plastic structure acts as a structural frame to hold vinyl canopy in both sides and tail gate of vehicle. In this paper, PPCP has been explored for canopy plastic structure part against conventional polyamides. Structural durability of the design was validated by virtual engineering. Part design and material combinations with better tooling design iterations were analyzed by using mold flow analysis.
Technical Paper

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

2017-11-27
2017-01-7011
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
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

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
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

Factors that Impact on Tire Structure Useful Life

2017-11-07
2017-36-0121
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
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

Vibration Absorber Application, Case Study: Mid-Size Truck Steering Wheel Vibration

2017-11-07
2017-36-0125
In this paper an alternative engineering solution to control vehicle steering wheel vibration is presented. The strategy is focused on the implementation of an effective tuned vibration absorber which also complies with time frame and costs requisites. The vibration levels in this case study are enhanced due resonances in the chassis frame and steering column. The tuned mass damper is basically a suspended mass attached on a vulcanized rubber body, aiming for the customer benefits; this solution can be classified as low cost as well low complexity for implementation. In this case study, a mid-size truck was used as a physical hardware and the data were collected through accelerometers on the steering wheel and other critical components. As a control factor, different tunings on different parts were applied to optimize the auxiliary system performance and robustness.
Technical Paper

Improve Frame Assembly Flexibility with Low Investment

2017-11-07
2017-36-0132
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.
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