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Journal Article

A novel ICE ON/OFF control strategy for hybrid electric bus based on route information

2018-04-13
2018-01-9075
Abstract: ICE ON/OFF control strategy is critical for fuel economy in the hybrid electric vehicle (HEV). The fuel cumsumption cut off at ICE is at OFF state when the vehicle stops especially at vehicle jams. It significantly profits for more fuel saving. Motor-only drive mode is rarely used in real-time control because of the power system meet the uncertain driver demand. Battery state of charge (SOC) balance also affects ICE ON/OFF control decision. ICE ON/OFF state optimization is still a critical problem that is rarely effectively resolved. Minimum Principle was used in real-time control and has a global optimization in many papers. However, there is no paper to apply this algorithm in ICE ON/OFF control optimization. This paper introduces a novel control method using Minimum Principle to select an appropriate ICE state, which extracts rules from the optimal results applied to real-time control based on predicted route information.
Journal Article

Design harmonization techniques to model vehicle lightweighting across diverse powertrains

2018-04-13
2018-01-9076
Vehicle lightweighting and advanced powertrains, including hybrid electric systems and high efficiency engines, have the potential to increase fuel economy and decrease life cycle energy and greenhouse gas (GHG) emissions. However, the energy and GHG impact over the entire vehicle life cycle is dependent on the energy and emissions required to produce lightweight materials and fuels. Recent work has used life cycle assessment (LCA) to evaluate diverse vehicles and fuels using a novel design harmonization technique. The current work describes this approach in further detail and provides an example of its application for a moderate lightweighting scenario for an internal combustion vehicle (ICV), hybrid electric vehicle (HEV) and plug-in hybrid electric vehicle (PHEV). This type of apples-to-apples comparison is enabled by functional equivalency metrics, which are defined as part of the design harmonization technique and held constant across all vehicles.
Journal Article

Aerodynamic Analysis of Cooling Airflow for Different Front-End Designs of a Heavy-Duty Cab-over-Engine Truck

2018-04-13
2018-01-9178
This paper deals with the analysis of cooling airflow for two different front-end designs of a heavy truck. The first design is a cab-over-engine (COE) cab; the second is a Soft Nose (SN) cab, which in this case is basically an elongation of the grille area of the COE cab to obtain a smoother shape of the cab. The SN model used in this investigation was extended 200mm from the COE front. Computational Fluid Dynamics (CFD) was used as the tool for examining the aerodynamic properties of the vehicle models. The configurations were evaluated both with inactive and active heat exchangers, in order to examine the effect of heating the air on the drag co-efficient and also to determine the cooling capacity of the different models. A sub- study was performed where different opening percentages of the grille area was investigated to determine the minimum percentage opening that would be needed to achieve a radiator Top Tank Temperature (TTT) value below a target limit of 100°C.
Technical Paper

Advanced Combustion for Improved Thermal Efficiency in an Advanced On-Road Heavy Duty Diesel Engine

2018-04-03
2018-01-0237
For internal combustion engines, the compression ratio (r) is defined as the ratio of volume at bottom dead center to the volume at top dead center and is a fundamental design parameter influencing the thermodynamic operation of the modern combustion engine. Thermodynamic cycle analysis can show that the cycle thermal efficiency increases as the compression ratio increases. An increase in the compression ratio changes the cycle such that peak compression pressure and temperatures are increased resulting in subsequent increases in the peak combustion pressure and temperature. Since the average temperature of heat addition is increased in the cycle, the thermal efficiency would theoretically increase as long as both cycles had the same heat rejection processes. These changes in peak pressure and temperature of the cycle must also be evaluated in terms of anticipated increases in engine friction and changes to the combustion duration respectively.
Technical Paper

Exploring the NOx reduction potential of Miller cycle and EGR on a HD diesel engine operating at full load

2018-04-03
2018-01-0243
The increasing demand for nitrogen oxides (NOx) reduction of diesel engines without sacrificing the total cost of ownership (TCO) which including the diesel fuel consumption and the aqueous urea solution consumption in the selective catalytic reduction (SCR) aftertreatment system, requires the development of more advanced combustion solutions. One promising strategy that can curb NOx emissions with a low fuel consumption penalty is to simultaneously reduce the combustion temperatures and pressures using Miller cycle and decrease the in-cylinder oxygen concentration by means of exhaust gas recirculation (EGR). As such, this strategy can minimize both diesel fuel and urea consumptions, enabling a low TCO. In this work, Miller cycle with late intake valve closing (IVC) and EGR technology were investigated on a single cylinder common rail heavy-duty diesel engine at a 24 bar indicated mean effective pressure (IMEP).
Technical Paper

In-cylinder Soot Reduction using Microwave Generated Plasma in an Optically Accessible Small-Bore Diesel Engine

2018-04-03
2018-01-0246
The present study explores the effect of in-cylinder generated non-thermal plasma on hydroxyl and soot development. Three optical diagnostics of electronically excited hydroxyl (OH*) chemiluminescence, Planar Laser Induced Fluorescence of OH (OH-PLIF) and Planar Laser Induced Incandescence (PLII) are performed in a single-cylinder optical diesel engine. Plasma was generated using a newly developed Microwave Discharge Igniter (MDI), which has the potential to accentuate the formation of active radical pools as well as suppress soot formation while stimulating soot oxidation. Methyl Decanoate fuel was specifically selected for diagnostics due to its low beam attenuation which is required for OH-PLIF and PLII.
Technical Paper

Variable valve actuation strategies for better efficiency, load range, and thermal management in an RCCI engine

2018-04-03
2018-01-0254
The Reactivity Controlled Compression Ignition (RCCI) concept for dual-fuel engines has challenges of which some can be overcome using Variable Valve Actuation (VVA) approaches. For various fuel combinations, the engine research community has shown that running dual-fuel engines in RCCI mode, improves thermal efficiency and results in ultra-low engine-out NOx and soot. Depending on available hardware, however, stable RCCI combustion is limited to a certain load range. At low load the combustion efficiency can drop significantly, whereas at high load the maximum in-cylinder pressure can easily exceed the engine design limit. In this paper, three VVA measures to increase load range, improve combustion efficiency, and perform thermal management are presented. Simulation results demonstrate the potential of these VVA measures for a heavy-duty engine running on natural gas and diesel.
Technical Paper

A Dynamic GUI Platform for Bluetooth Automotive Application Voice Communication Package

2018-04-03
2018-01-0023
In this paper, a reconfigurable object oriented simulator is proposed to analyze the performance of Bluetooth Voice Communication Package (VCP) for telecom purposes like hands-free vehicular communication. It consists of a graphical user interface (GUI) for research or validation engineers to investigate system specific performance. For example, a research engineer can utilize this GUI to analyze a system performance using different noise reduction filtering techniques in vehicular hands-free applications. Also, a validation engineer can utilize this GUI to evaluate vehicular Bluetooth audio quality for different vehicles at different driving conditions (e.g. speeds, fan levels, etc.). The proposed Bluetooth VCP model consists of modules like Audio Equalization (EQ), Acoustic Echo Canceler (AEC) and Noise Suppression (NS). This dynamic GUI platform provides the scope to add and analyze new proposed filtering techniques.
Technical Paper

Temperature Measurements of the Piston Optical Window in a Research Compression Ignition Engine via Thermography and Thermocouples

2018-04-03
2018-01-0083
Internal combustion engines are characterized by high pressure and temperature loads on pistons and cylinders. The heat generated by the combustion process is dissipated by means of water and oil cooling systems. For the best design and optimization of the engine components is necessary to know the components temperature in order to estimate the thermal flows. The purpose of this work is to measure the piston sapphire window temperature in a research optically accessible engine by combining two different techniques: thermocouples measurements and thermography. The first is a well consolidated method that provides a reliable value of temperature. On the other hand, it requires high technical level to be applied because of the use of linkage systems to support the thermocouples wires or even more skills when wireless data transmission is set.
Technical Paper

Development of a Compact and High-Performance Radiator for Thermal Management of Environmentally-Friendly Cars

2018-04-03
2018-01-0087
To comply with increasing fuel efficiency regulations, a low temperature radiator (LT radiator) is required to cool the charge-air system of a turbocharged engine. Since heavy-duty and high-performance vehicles demand high cooling performance, their main radiators alone are typically insufficient in meeting the vehicle’s cooling requirements. An additional radiator installed in the front of the wheel well is required to meet the extra cooling demand. In order to install this radiator in the front of the wheel well, guaranteed performance in the limited packaging space and impact resistance of the leading tube edge are required. We developed the Supplementary Inner-Fin Radiator (SIR) which achieves the compact, high performance, and durability requirements by use of an inner-fin tube. The purpose of this paper is to report our design approach and product specifications of the SIR.
Technical Paper

Powertrain Warm-up Optimization Involving Simplified Split Cooling With Integrated Waste Heat Recovery and Reuse.

2018-04-03
2018-01-0086
This study is a continuation of the earlier study published in SAE #2016-01-0647. The earlier test results have proven that the previously proposed engine cooling circuit when combined with exhaust heat recovery and reuse could expedite the warm-up process after cold-start and has improved the fuel economy by up to 4%. With the earlier concept being evolved further, the study discussed in this paper explores further improvements that can be made to the cooling circuit to further expedite the warm-up process. In particular, with some changes to the cooling circuit, the heat recovered from the exhaust gas can be reused right away to heat up the heat exchangers for engine oil, CVT oil and cabin heater before the coolant is recirculated into the engine. Next, the thermostat opening temperature and leakage rate can also be optimized to prolong the heat recirculation period.
Technical Paper

ANALYSIS OF CURRENT SITUATION WITH RELIABILITY PREDICTION

2018-04-03
2018-01-0100
This paper will discuss the problem of improving reliability prediction on the basis of analysis advantages and disadvantages of current situation in theoretical and practical aspects of reliability prediction for industry. This relates to different areas of engineering. Predicting is inaccurate when it is based on information obtained from using traditional approaches of accelerated life testing (ALT) data where the degradation (failure) process differs substantially from the product’s degradation process during service life under real world conditions. The paper will consider currently used reliability prediction methods through the analysis of publications and author’s thinking. It will be analyze why considered reliability prediction approaches not successful in industry that leads to many recalls, less reliability, durability, maintainability, and profit, and higher life cycle cost of the product that might be.
Technical Paper

The Synthetic 3DOF Wheel Force for Passenger Vehicle Based on Predicted Frequency Response Function Model

2018-04-03
2018-01-0123
In order to meet developmental targets and minimize costs, wheel force transducer is the best option when it is being used in targeting customer usage research or determining the effective use of the proving ground. However, the huge cost and low practicability of using wheel force transducer on a fleet test of customer vehicles are often prohibitive, as a result engineers have to choose other transducer measures. This paper describes an effective wheel force prediction approach by using the model of vehicle dynamic system built via the means of frequency response function (FRF). A vehicle system linear modeling technique is being discussed. For the system identification of FRF, the acceleration and wheel force time history data, as system input and output, are collected from an instrumented passenger car as it traverses in different real-world proving ground surfaces.
Technical Paper

Deriving the validation protocol for isolator switches used in Commercial vehicles

2018-04-03
2018-01-0128
Automotive business is more focused towards delivering a highly durable and reliable product at an optimum cost. Anything falling short of customer expectation, will damage the reputation of the manufacturer. To exterminate this, all automotive components undergo stringent testing protocol during the design validation phase. Nevertheless, there are certain factors in the field which are seldom captured during design validation. This project aims at optimizing a validation methodology for Isolator switch based on field usage and conditions. Isolator switch is the main control switch which connects/disconnects the electrical loads from its source; battery. This switch is used in the electrical circuit of the vehicle to prevent the unwanted draining of battery when it is not needed (or) vehicle is in switched off state. In the electrical version of this switch uses electromagnetic coils to short the contacts.
Technical Paper

Advanced MacPherson Strut Bending Model for Improved Accuracy Using Simple Inputs

2018-04-03
2018-01-0137
Mechanism simulation of automotive suspension systems has been constantly evolving and improving, to add additional fidelity to results. This improves correlation to physical test data, and allows the tools to be used to study more advanced phenomenon. MacPherson strut suspensions have been popular for decades due to their decreased parts count resulting in lower system costs. The strut in this kind of suspension performs multiple tasks, in addition to supporting the springing and damping loads, it also functions as a kinematic support as part of the overall mechanism. In simplified MacPherson strut simulations, the rod of the MacPherson strut is treated as a rigid body. However, when one compares system level physical test data with simulation data using this rigid body approach, it is apparent that the bending of the strut road influences the system level kinematics and compliances of the suspension.
Technical Paper

Reduction of Parasitic Losses in Front-End-Accessory-Drive Systems – Part 2

2018-04-03
2018-01-0326
Demanding CO2 and fuel economy regulations are continuing to pressure the automotive industry into considering innovative powertrain and vehicle-level solutions. Powertrain engineers continue to minimize engine internal friction and transmission parasitic losses with the aim of reducing overall vehicle fuel consumption. In the first part presented in 2017 the authors described the design of a flexible test stand allowing to test air conditioning systems as well as alternators. The first part focused on the collection of existing data as well as identification of potential areas for improvement. The second part of the series will focus exclusively on the operation of the alternator. Two main elements of the study will be discussed. The first part explores extensive tests performed to evaluate the main design aspects of the component. Different belt designs, routing, and tension levels were tested and compared.
Technical Paper

Combined Experimental and Numerical Investigation of the ECN Spray G Under Different Engine-Like Conditions

2018-04-03
2018-01-0281
Compared to standard Gasoline Port Fuel Injection (PFI) techniques, Direct Injection (GDI) applied to spark-ignition (SI) engines allows for many technical advantages, among which the most relevant are an increased power output, a higher fuel efficiency and better cold start performances, which thus lead to lower emission levels and fuel consumption. On this basis, it is with renewed interest that the GDI technology is currently investigated both in terms of experimental and numerical researches. Within this context, multi-dimensional simulations of different ECN Spray G conditions were performed with the LibICE code, coupled with the open source OpenFOAM CFD software, by using RANS turbulence modeling and a Lagrangian approach for the spray. Attention was put on the investigation of liquid and vapor penetrations along with spray morphology and plume interaction, by comparing the computed results against Mie scattering and schlieren experimental data.
Technical Paper

Thermo-mechanical fatigue testing of welded tubes for exhaust applications

2018-04-03
2018-01-0090
Some selected steel sheets for exhaust applications were tested under thermos-mechanical fatigue (TMF) condition within 400-800oC with partial constraint. Straight welded tubes were used as coupons to enable large compression without buckling and understanding the effect of weld as well. Repeated tests confirmed the observed failure scenario for each material type. The hysteresis loop behaviours were also simulated using the mechanism-based integrated creep and fatigue theory (ICFT) model. Although more development is needed, for quick material screening purpose, this type of testing could be a very cost effective solution for materials and tube weld development for exhaust applications.
Technical Paper

Blind Prediction of crash performance of a Composite bumper & Crush cans using RADIOSS

2018-04-03
2018-01-0114
In 2016 the United States Automotive Materials Partnership (USAMP) approached Altair with a desire to establish the current state-of-the-art of the explicit finite element software, RADIOSS, for predicting the crash behavior of composite laminates as it relates to application in the automotive industry. Coupon and component level test data were supplied to help with the development of material modeling. Final correlation was to a series of “blind” sled tests completed on a composite bumper and crush cans. The data from these tests was shared only after Altair submitted the RADIOSS predictions to USAMP
Technical Paper

Systematic investigation of fuel film evaporation

2018-04-03
2018-01-0310
In gasoline direct injection (GDI) engines fuel wall films are the major source of particulate emissions. To understand and avoid the fuel film formation, measurements of the fuel film mass, size and pattern are important. However in practical applications fuel films might be not problematic as long as these have evaporated in time before ignition. Therefore we performed systematic measurements of the evaporation duration of fuel films resulting from spray/wall interaction using high-speed visualization. The investigation focusses on the influence of engine related operation parameter on the film evaporation duration under the conditions of homogeneous charged gasolines engines. To be able to distinguish the effects of different operation parameters on the evaporation durations, the measurements were performed inside a pressure vessel.
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