Browse Topic: Starters and starting

Items (689)

Carburizing and Heat Treatment of Carburizing Grade Steel Parts

AMS2759/7E (Historical)9/15/2021

This specification, in conjunction with the general requirements for steel heat treatment covered in AMS2759, establishes the requirements and procedures for three classes of gas, vacuum, liquid, and low pressure (LPC) carburizing and related heat treatment of parts fabricated from carburizing grade steels. Parts made from steels other than those specified in the detail specifications may be heat treated in accordance with the applicable requirements using processing temperatures, times, and other parameters recommended by the material producer unless otherwise specified by the purchaser. This specification does not cover pack carburizing.

AMS B Finishes Processes and Fluids Committee

Coordination Control Strategy for Mode Switching of a Parallel Hybrid Electric System Based on Continuously Variable Transmission

02-13-02-0010

8/11/2020

This study aims to solve the problem of impact in a parallel hybrid electric system based on the continuously variable transmission (CVT) during switching from pure electric mode to engine-driven, power-generating mode. Taking into account the torque response characteristics of the engine and motor and the dynamic characteristics of the wet clutch hydraulic control system, the mode switching process is divided into six stages, namely, pure electric mode, wet-clutch free travel, engine start-up, engine speed synchronization, clutch combination, and engine intervention drive. A coordination control strategy is developed based on the model predictive control algorithm to ensure smooth mode switching. The effectiveness of the control algorithm is verified using Matlab/Simulink and the AMESim co-simulation platform. Results show that with the mode switching coordination control strategy, the components of the system work harmoniously. The maximum impact is reduced by 52.0% at the speed synchronization stage and by 84.3% at the clutch coupling stage compared with the uncoordinated control situation.

Zeng, Xiaohua, Li, Xiaojian, Dong, Bingbing

An Efficient Path Planning Methodology Based on the Starting Region Selection

2020-01-01184/14/2020

Automated parking is an efficient way to solve parking difficulties and path planning is of great concern for parking maneuvers [1]. Meanwhile, the starting region of path planning greatly affects the parking process and efficiency. The present research of the starting region are mostly determined based on a single algorithm, which limits the flexibility and efficiency of planning feasible paths. This paper, taking parallel parking and vertical parking for example, proposes a method to calculate the starting region and select the most suitable path planning algorithm for parking, which can improve the parking efficiency and reduce the complexity. The collision situations of each path planning algorithm are analyzed under collision-free conditions based on parallel and vertical parking. The starting region for each algorithm can then be calculated under collision-free conditions. After that, applicable starting regions for parking can be obtained, and each of those regions corresponds to a parking path planning algorithm. However, there always exists overlapped starting regions, which can be applied to multiple parking path planning algorithms. In order to select the most suitable algorithm to plan the parking path, the priority order of algorithms is decided based on the preference criterion function. The collision-free parking path can be generated following the priority order. Based on the modified B-spline curves, a continuous-curvature path is presented. The simulation results based on MATLAB/Simulink and PreScan show that the methodology can smoothly judge the feasibility of automated parking in vehicle’s current position and plan the most suitable parking path. The proposed methodology can calculate the starting region of automated parking rapidly and plan more efficient parking path compared with other methods.

Chen, Xin, Qin, Zhaobo, Fan, Jingjing, Zhou, Huajian, Chen, Liang

Effect of Oil Viscosity and Driving Mode on Oil Dilution and Transient Emissions Including Particle Number in Plug-In Hybrid Electric Vehicle

2020-01-03624/14/2020

Plug-in electric vehicle (PHEV) has a promising prospect to reduce greenhouse gas (GHG) emission and optimize engine operating in high-efficiency region. According to the maximum electric power and all-electric range, PHEVs are divided into two categories, including “all-electric PHEV” and “blended PHEV” and the latter provides a potential for more rational energy distribution because engine participates in vehicle driving during aggressive acceleration not just by motor. However, the frequent use of engine may result in severe emissions especially in low state of charge (SOC) and ahead of catalyst light-off. This study quantitatively investigates the impact of oil viscosity and driving mode (hybrid/conventional) on oil dilution and emissions including particle number (PN). Two cycles, WLTC (World-wide Harmonized Light Duty Driving Test Cycle) and continuous ECE 15 (European Driving Cycle), were adopted and initial SOC was controlled in the range of 10-13%, which can induce more engine start events. Oil dilution is detected through method of ASTM D3525-04 to identify dilution rate under different conditions. Results show that both in WLTC and ECE 15, frequent engine start will causes high PN and unburned hydrocarbon emissions while NOx is substantially reduced due to relatively low engine loads except in first cold start. Intermittent engine start also significantly accelerates dilution rate but this rate for 5W-30 increases more rapidly than 0W-20 does in hybrid driving mode. Moreover, 5W-30 oil increases fuel consumption due to higher friction work compared to 0W-20 does and the emission of PN along with NOx and THC is also increased.

Fan, Qinhao, Wang, Yunfei, Xiao, Jianhua, Wang, Zhi, Li, Weizi, Jia, Tian, Zheng, Bin, Taylor, Robert

Relevance of Exhaust Aftertreatment System Degradation for EU7 Gasoline Engine Applications

2020-01-03824/14/2020

Exhaust aftertreatment systems must function sufficiently over the full useful life of a vehicle. In Europe this is currently defined as 160.000 km. With the introduction of Euro 7 it is expected that the required mileage will be extended to 240.000 km. This will then be consistent with the US legislation. In order to quantify the emission impact of exhaust system degradation, an Euro 7 exhaust aftertreatment system is aged by different accelerated approaches: application of the Standard Bench Cycle, the ZDAKW cycle, a novel ash loading method and borderline aging. The results depict the impact of oil ash on the oxygen storage capacity. For tailpipe emissions, the maximum peak temperatures are the dominant aging factor. The cold start performance is effected by both, thermal degradation and ash accumulation. An evaluation of this emission increase requires appropriate benchmarks. For this purpose, an analysis of the emission impacts of ambient temperatures, driving modes and particulate filter regenerations follows. The comparison shows the severe impact of very low ambient conditions. Considering the high statistical relevance of catalyst degradation however, full useful life optimization requires special attention for Euro 7 gasoline engine applications.

Sterlepper, Stefan, Claßen, Johannes, Pischinger, Stefan, Görgen, Michael, Cox, Jim, Nijs, Martin, Scharf, Johannes

Effects of Using an Electrically Heated Catalyst on the State of Charge of the Battery Pack for Series Hybrid Electric Vehicles at Cold Start

2020-01-04444/14/2020

Battery models are being developed as a component of the powertrain systems of hybrid electric vehicles (HEVs) to predict the state of charge (SOC) accurately. Electrically heated catalysts (EHCs) can be employed in the powertrains of HEVs to reach the catalyst light off temperature in advance. However, EHCs draw power from the battery pack and hence sufficient energy needs to be stored to power auxiliary components. In series HEVs, the engine is primarily used to charge the battery pack. Therefore, it is important to develop a control strategy that triggers engine start/stop conditions and reduces the frequency of engine operation to minimize the equivalent fuel consumption. In this study, a battery pack model was constructed in MATLAB-Simulink to investigate the SOC variation of a high-power lithium ion battery during extreme engine cold start conditions (-7°C) with/without application of an EHC. The EHC was simulated in MATLAB to determine the energy required to heat the catalyst during cold start conditions. The effect of the EHC in emissions purification at -7°C was studied using a three-way catalyst (TWC) model. The EHC was operated only during the initial few seconds before the engine start to increase the bed temperature of the catalyst. This was found to have a significant impact on exhaust gas emissions even under cold start conditions. However, powering the EHC lowered the SOC of the battery pack, triggering the engine to run and consume more fuel. Hence, an engine ON/OFF control strategy was proposed to control the engine operation conditions and effectively charge the battery pack. The SOC variation of the battery pack and the effects on emissions and fuel consumption were simulated and compared with/without the EHC. The battery model was validated with a control strategy proposed in simulations at 23°C and a parameter study was conducted at -7°C.

Sivakumar, Suchitra, Shingyouchi, Hajime, Yan, Xieyang, Okajima, Toshinori, Yamaguchi, Kyohei, Kusaka, Jin, Nagata, Makoto

RDE-Compliant PEMS Testing of a Gasoline Euro 6d-TEMP Passenger Car at Two Ambient Temperatures with a Focus on the Cold Start Effect

2020-01-03794/14/2020

European Union RDE (real driving emissions) legislation requires that new vehicles be subjected to emissions tests on public roads. Performing emissions testing outside a laboratory setting immediately raises the question of the impact of ambient conditions - especially temperature - on the results. In the spirit of RDE legislation, a wide range of ambient temperatures are permissible, with mathematical moderation (correction) of the results only permissible for ambient temperatures <0°C and >+30°C. Within the standard range of temperatures (0°C to +30°C), no correction for temperature is applied to emissions results and the applicable emissions limits have to be met. Given the well-known link between the thermal state of an engine and its emissions following cold start, ambient temperature can be of great importance in determining whether a vehicle meets emissions requirements during an RDE test. This paper reports the results of full RDE-compliant on-road emissions tests performed on a Euro 6d-TEMP passenger car with a direct injection spark ignition engine and a gasoline particle filter. Testing was performed at two temperatures, both lying within the “standard” temperature range for RDE testing: +25°C and +8°C. Regulated gaseous emissions, particle number and CO2/fuel consumption results are presented and discussed. Overall, as expected, emissions following cold start were significantly higher at the lower test temperature. Nevertheless, the long distance covered during RDE tests (~70-100 km) and their urban phases (>16 km, often ~25 km) weakens the impact of this effect. Some simple mathematical analyses of the results from various portions of the trip are presented.

Bielaczyc, Piotr, Merkisz, Jerzy, Pielecha, Jacek, Woodburn, Joseph

On Shedding Frequency and Aerodynamic Characteristics of a Rotating Wire-Wrapped Cylinder

2020-01-00283/10/2020

Numerical and experimental investigations of shedding frequency of rotating smooth and wire-wrapped cylinders, placed in steady flow have been performed. The freestream mean velocity was 10 m/sec. and for the numerical investigations, the smooth cylinder diameter was 5 cm, which corresponds to an approximate Reynolds number based on cylinder’s diameter of 3.2x104. The wire-wrapped cylinder had a wire diameter of 5 mm and the ratios of pitch spacing to the cylinder diameter, p/D, was 1.0. The cylinder length to diameter ratio was 20. The rotation rates (λ) were 0.5 and 2.0. To obtain the shedding frequency, numerical probes were placed at 3D downstream, 0.5 D above the centerline, and at 0.5D, spaced along the spanwise direction and the shedding frequencies were obtained from spectra of the axial velocity. Results indicate that the lift for the wire-wrapped cylinder is nearly 150% of that of the smooth cylinder, however, it has a higher drag force. Details of the flow indicate wire-wrapping reduces spanwise coherency and increases the phase angle of vortices, resulting in increased lift. Experimental results indicate a similar trend as the numerical results, with wire-wrapping, reduces the shedding oblique angle and with rotation, reduced peak energy, breaking down the large eddies into smaller eddies of different frequencies.

Rahai, Hamid R., Bonifacio, Jeremy, Begum, Assma, Gada, Komal

The Road to the Top is Not on the Map Personal Journal

R-5032/10/2020

The Road to the Top is Not on the Map Personal Journal is designed to accompany the best-selling book by Carla Bailo and Terry Barclay. While enjoying The Road to the Top is Not on the Map, readers can capture their own thoughts, ideas and feelings in this journal. Thoughtful writing prompts helps users clarify the habits, motivations, triumphs, defeats, and lessons learned throughout their career. To further enhance the experience of The Road to the Top is Not on the Map, the journal includes guidelines for starting a book club with discussion questions.

Bailo, Carla, Barclay, Terry

Akasol packs industry-leading energy density into new battery design

19TOFHP12_0812/1/2019

Projecting the market for full-electric and hybrid-electric commercial vehicles will continue to expand, Germany-based lithium-ion battery specialist Akasol recently announced production-readiness of a newly-developed battery pack that sets an energy-density benchmark. The company's president also confirmed Akasol will build a manufacturing facility in the Detroit area targeted to begin production in mid-2020. Akasol has a 30-year history of producing battery systems for buses and other commercial vehicles, as well as railway and marine applications. President Roy Schulde says the new American plant is being constructed primarily to build battery packs for buses constructed by European-brand customers doing business in the U.S. The company already claims Europe's largest commercial-vehicle lithium-ion battery production facility.

Visnic, Bill

Algorithm Gives Robots a Faster Grasp

TBMG-3561512/1/2019

A robot that's sorting through a bin of objects and attempting to get a good grasp on one of them is performing a computationally taxing maneuver. Before even attempting the move, it must calculate a litany of properties and probabilities such as the friction and geometry of the table, the pen, and its two fingers, and how various combinations of these properties interact mechanically based on fundamental laws of physics.

Study on Engine Start Vibration Index in a Hybrid Powertrain Using Torque Sensor and Cylinder Pressure Sensor

2019-01-503411/4/2019

This paper presents an investigation of drivability issue of engine start-stop. Hybrid vehicles provide excellent benefits regarding fuel efficiency and emission. However, vibration results from constant engine start and stop events generate drivability issues, thus compromising driving comfort. This paper has designed a high speed torque sensor to capture instantaneous torque at the engine shaft. Its consequences help to find out the most suitable index of vibration severity. This paper is organized in four sections. The first section introduces the powertrain to be studied. The second section introduces development of a specially designed torque sensor. The torque sensor is installed between the engine and ISG (Integrated Starter Generator), alongside with an encoder. The torque sensor is utilized to collect the instantaneous shaft torque on occasion of engine start. In the third section, this paper has performed two experiments. Firstly, a typical engine start process (from 0 to 650 rpm) is studied. Instantaneous shaft torque, encoder signal and cylinder pressure signals are gathered and synchronized. Cranking phase and initial combustion phase is observed. It is concluded that torque generated from cylinder pumping air is the main contributor to the engine torque ripple, which is the main cause of vibration. Use that, three vibration index candidates are bought out, and square of angular acceleration is chosen. Then, this paper performed another experiment with an engine working at 1000 rpm and 100 Nm to examine the performance of vibration index. The results show the effectiveness of vibration index.

Yang, Fuyuan, Du, Lei, Hu, Yaodong

Tricks of the EV trade

19AUTP11_0411/1/2019

Why Volvo uses starter-generators and raised tunnels for its electrified vehicles. Volvo first demonstrated its Integrated Starter Generator (ISG) at the 2001 Frankfurt Motor Show. Replacing the starter-motor and alternator with the ISG allows a gas engine to shut off at will - mainly to prevent idling at a stop. For the company, it was a logical first step for fuel savings. But Volvo engineers at the time could hardly have predicted how useful an ISG would become, decades later, in the electric era. As Automotive Engineering discovered on our recent drive of the 2020 Volvo XC90 T8 plug-in hybrid during its media launch, an integrated crankshaft generator doesn't merely allow stop-start or mild-hybrid propulsion. While piloting the XC90 T8 along the Trans-Canada Highway in August, we were able to keep the three-row, full-size SUV in pure electric mode for its first 21 miles (34 km).

Berman, Bradley

Guarding of Starter System Energization

J1493_201908 (Current)8/8/2019

This SAE Standard describes guarding to help prevent hazardous machine movement caused by activation of the starter motor by bypassing the starter control system. This document is applicable to off-road, self-propelled work machines, as identified in SAE J1116, and agricultural tractors, as defined in ANSI/ASAE S390, which have the potential for hazardous machine movement as a result of bypassing the starter control system and powering of the starter motor.

OPTC1, Personnel Protection (General)

Extension of a 2D Algorithm for Catch Efficiency Calculation to Three Dimensions

2019-01-20136/10/2019

Accurate calculation of the catch efficiency β is of paramount importance for any ice accretion calculation since β is the most important factor in determining the mass of ice accretion. A new scheme has been proposed recently in [1] for accurately calculating β on a discretized two-dimensional geometry based on the results of a Lagrangian droplet trajectory integrator (start and impact conditions). This paper proposes an extension to the algorithm in Ref. [1], which is applicable to three-dimensional surfaces with arbitrary surface discretization. The 3D algorithm maintains the positive attributes of the original 2D algorithm, namely mass conservation of the impinging water, capability to deal with overlapping impingement regions and with crossing trajectories, computational efficiency of the algorithm, and low number of trajectories required to reach good accuracy in catch efficiency. At the same time, the new 3D algorithm avoids typical difficulties of other approaches to determine the catch efficiency β, like noisy β (results varying significantly between neighboring surface cells), catch efficiency of zero for surface cells surrounded by other cells with β > 0, jagged impingement limits, catch efficiency β not available on the discretized surface but only on an intermediate plane, or interpolation problems of β between an intermediate plane and the actual discretized surface. The paper first reviews existing approaches in the literature to determine β, then describes in detail the extension of the algorithm in [1] to three dimensions and the steps taken to avoid the possible pitfalls in calculating β described above. The algorithm is then applied to two test problems, one being the wing/belly-fairing intersection of the Common Research Model (CRM) in clean configuration [2] and the other being a generic scoop intake. The paper closes with ideas for further development of the algorithm.

Bartels, Christian, Neubauer, Thomas, Hassler, Wolfgang

A Study of Droplet Breakup in the Vicinity of an Airfoil

2019-01-20006/10/2019

Supercooled large droplets can breakup before imping on aerodynamic surfaces and this should be taken into account in the icing codes. A study of droplets breakup in the vicinity of an airfoil has been conducted. Experiments for streams of droplets that were allowed to fall in the path of an incoming airfoil attached to a rotatory arm were conducted at the INTA facility. Droplets diameters ranged from 500 μm to 3 mm and two airfoils models of leading edge radius of 70 mm and 103 mm moving at velocities of 70 m/s, 80 m/s and 90 m/s were tested. Two subsets of experimental data for both bag and stamen breakup and shear breakup modes were used in this investigation. For these cases a numerical trajectory and deformation model was applied to obtain the evolution of the horizontal position, and the droplet maximum and minimum diameter. Breakup onset was determined from experimental data. Though previous works considered that breakup starts when there is a minimum in the minimum diameter, such minimum was not found in the integration of the model. However, it was found a minimum in the derivative of the minimum diameter at the breakup onset. The implication of this finding has been discussed. Additionally, the minimum in the derivative of the minimum diameter is compared to a previous empirical breakup criterion and the results of the comparison have been discussed.

Sor, Suthyvann, Garcia-Magariño, Adelaida, Velazquez, Angel

Simulations of Thin Film Dynamics on a Flat Plate and an Airfoil

2019-01-19386/10/2019

The goal of the present study is to investigate the dynamics of a thin water film on a flat plate and an airfoil using direct numerical simulation (DNS). The first case for a wetted flat plate is used to model former experiments and investigate the dynamics of a wind-driven water film. The second case for a thin film on a NACA 0012 airfoil of chord length 0.5 m is used to investigate the dynamics of a wind-driven water film on a curved surface. Particular attention is paid to the interaction between the liquid film and the air shear-layer above the film. As the incoming airflow moves over the thin water film, instability is triggered at the gas-liquid interface. Interfacial waves develop and are advected downstream. The interaction between the air flow and the interfacial waves induces shedding vortices near the interface, which in turn perturb the liquid film farther downstream. Simulations are performed using the open source multiphase flow solvers, Gerris and Basilisk. Both solvers employ a finite-volume approach and the interface is captured using a Volume-of-Fluid (VOF) method. While the long-term goal of this research effort is to investigate glaze ice formation in water films on airfoils, the current simulations focus on liquid film dynamics starting with a constant thickness exposed to a relatively low flight airspeed. The resulting simulations demonstrate the unsteady film dynamics and thickness evolution and natural waviness generated by the liquid-film and free-stream flow interactions.

Sakakeeny, Jordan, McClain, Stephen T., Ling, Yue

A Penalization Method for 2D Ice Accretion Simulations

2019-01-19396/10/2019

Numerical tools for 3D in-flight icing simulations are not straightforward to automate when seeking robustness and quality of the results. Difficulties arise from the geometry and mesh updates which need to be treated with care to avoid folding of the geometry, negative volumes or poor mesh quality. This paper aims at solving the mesh update issue by avoiding the re-meshing of the iced geometry. An immersed boundary method (here, penalization) is applied to a 2D ice accretion suite for multi-step icing simulations. The suggested approach starts from a standard body-fitted mesh, thus keeping the same solution for the first icing layer. Then, instead of updating the mesh, a penalization method is applied including: the detection of the immersed boundary, the penalization of the volume solvers to impose the boundary condition and the extraction of the surface data from the field solution. Although the current work is intended for 3D simulations, the content of this paper is limited to 2D applications to show the feasibility of the method. Tests are performed on multi-step rime and glaze ice cases where it is observed that the penalization method is able to produce sensible ice shapes compared to a body-fitted approach. However, accurate results are only achieved if the mesh is a priori refined in the zone where ice accretion is expected. The paper will further discuss the computational time, mesh refinement requirements, accuracy, limitations and recommendations for improvement of the penalization method applied to icing.

Lavoie, Pierre, Blanchard, Ghislain, Radenac, Emmanuel, Laurendeau, Eric, Villedieu, Philippe

Separating-Reattaching Flows Over an Iced Airfoil

2019-01-19466/10/2019

Delayed Detached Eddy Simulations (DDES) of separating-reattaching flows on the suction side of an ice-contaminated airfoil were conducted. A single-section straight-wing NACA23012 airfoil with leading-edge ice was studied. The geometry represents a realistic glaze horn-ice contamination obtained during the icing test campaigns described in [1], which has aerodynamic data for comparison. The three-dimensional transient flow behavior was simulated using the open-source flow solver OVERFLOW, version 2.2l [2] developed by NASA Langley Research Center. Configurations at three angles of attack that exhibit unsteady flow behavior starting with the bursting angle were examined at Mach number of 0.18 and Reynolds number of 1.8x106. As the stall angle was approached the aerodynamic performance parameters displayed large-scale unsteadiness where periods of attached and separated flows were observed. The time-averaged results show good agreement with the aerodynamic test data. The calculated Strouhal number for the self-sustained low-frequency oscillations is consistent with the previous experimental research.

Oztekin, Ezgi, Riley, James

Hydraulic Excavator Operator Controls

J1177_201906 (Current)6/6/2019

This standard covers mobile hydraulic excavator controls and the specific arrangement and direction of motion for the primary controls. This standard applies to mobile hydraulic excavators as described in ISO 7135—Earthmoving machinery—Hydraulic excavators—Terminology and commercial specifications, and ISO 6165—Earthmoving machinery—Basic types—Vocabulary.

MTC1, Earthmoving Machinery

Modeling of Close-Coupled SCR Concepts to Meet Future Cold Start Requirements for Heavy-Duty Engines

2019-01-09844/2/2019

The low-NOx standard for heavy-duty trucks proposed by the California Air Resources Board will require rapid warm-up of the aftertreatment system (ATS). Several different aftertreatment architectures and technologies, all based on selective catalytic reduction (SCR), are being considered to meet this need. One of these architectures, the close-coupled SCR (ccSCR), was evaluated in this study using two different physics-based, 1D models; the simulations focused on the first 300 seconds of the cold-start Federal Test Procedure (FTP). The first model, describing a real, EuroVI-compliant engine equipped with series turbochargers, was used to evaluate a ccSCR located either i) immediately downstream of the low-pressure turbine, ii) in between the two turbines, or iii) in a by-pass around the high pressure turbine. These simulations indicate that the location downstream of the low-pressure turbine offers nearly the best NOx conversion, and that the optimal volume of the ccSCR in this location is 25% of a conventional SCR catalyst. The second model describes a conventional heavy-duty aftertreatment system, to which a ccSCR was added. This model was used to examine the performance of the ccSCR in the context of the full ATS. Optimization of the diesel oxidation catalyst (DOC) and SCR catalyst designs in this system was considered, as well as the use of an NH3 storage-based control strategy for DEF dosing to the SCR catalysts.

Harris, Thomas Miller, Mc Pherson, Kristoffer, Rezaei, Reza, Kovacs, David, Rauch, Hendrik, Huang, Yinyan

Study of Flash Boiling Spray Combustion in a Spark Ignition Direct Injection Optical Engine Using Digital Image Processing Diagnostics

2019-01-02524/2/2019

Flash boiling spray has been proven to be a useful method in providing finer fuel droplet and stronger evaporation in favor of creating a homogeneous fuel-air mixture. Combustion characteristics of flash boiling spray are thus valuable to be investigated systematically for aiding the development of efficient internal combustion system. An experimental study of flash boiling spray combustion in a SIDI optical engine under early injection has been conducted. The fuel, Iso-octane, was used across all tests. Three fuel spray conditions experimented in the study: normal liquid, transitional flash boiling and flare flash boiling sprays, within each case that Pa/Ps ratio was set in (>1), (0.3~1), and (<0.3) respectively. A small quartz insert on the piston enables optical access for observing combustion process; non-intrusive measurements on flame radicals has been carried out using a high-speed color camera. With the use of digital image processing and color analysis, the imaging system was turned into an abstract multi-spectral system to determine the characteristics of flame emission. In addition, the near infrared region was capable of being discriminated from the rest regions of the flame using HSV color model. The near infrared flame area and diffusion flame region as well as pool fire were found to be reduced, when implementing flash boiling spray under early injection condition. It is found that flash boiling spray contributes the reduction of particulate number (PN) emissions in exhaust gas and makes the improvement of indicated mean effective pressure (IMEP) and cyclic variation, which lead to more efficient combustion in SIDI engine under early injection.

Sun, Zhe, Ma, Zhen, Li, Xuesong, Xu, Min

Experimental Investigations on the Performance and Cold Starting Characteristics of a Low Compression Ratio Diesel Engine

2019-01-05584/2/2019

In this experimental work, the potential advantages of lowering the Compression Ratio (CR) of a diesel engine in terms of performance, combustion and emission related parameters along with the analysis and improvement in its cold starting characteristics are presented. The CR of a single cylinder direct injection common rail diesel engine used for light-duty automotive applications was lowered from 18:1 to 14:1 by suitable modifications to the combustion bowl while retaining its shape. The engine with both the CRs was tested on a dynamometer rig under similar operating and fuelling conditions. Additionally, experiments were carried out to determine the extent to which in-cylinder smoke emissions can be reduced when the Nitric Oxide (NO) levels of 14 CR are matched to the higher levels seen in 18CR. In order to evaluate cold start ability and idling stability of the engine with a reduced CR (14:1), the engine was instrumented inside a cold chamber. The engine was soaked at different low temperatures ranging from 25 °C to -7 °C and experiments were performed to determine its cold start ability. The effects of injection scheduling and injection quantity on cold start ability are determined with the help of an open engine controller. Further, the improvement on start ability with the help of a grid heater was also evaluated.

Mithun, S, Ramesh, A

SAE Architecture Analysis and Design Language (AADL) Annex Volume 2:Annex B: Data Modeling AnnexAnnex D: Behavior Model AnnexAnnex F: ARINC653 Annex

AS5506/2 (Current)2/18/2019

AS-2C Architecture Analysis and Design Language

New Catalyst for Plastic Production Also Creates Hydrogen

TBMG-3339012/1/2018

Researchers have developed a new, low-cost catalyst for plastic production that turns a biorefinery product into a starting material for the synthesis of plastics, which could represent a sustainable alternative to widespread PET. At the same time, hydrogen can also be formed during the reaction.

Development of a Climate and Altitude Simulation Test Bench for Handheld Power Tools

2018-32-003310/30/2018

A climate and altitude conditioning test bench was developed at the Institute of Energy Efficient Mobility (IEEM) of Karlsruhe University of Applied Sciences to evaluate the overall sustainability of using innovative biofuels in handheld power tools such as chainsaws, trimmers and blowers under any typical operating condition worldwide. The 6 m3 hermetically sealed and thermally insulated test chamber is large enough to fit the entire power tool. A two-stage refrigeration system with intake air drying and electric heating allows for realistic temperature conditions to be set in the test chamber, ranging from arctic cold to tropical heat (-28 to 45 °C). Altitudes of up to 3500 m above sea level can be simulated using a throttle valve at the inlet of the chamber and a pressure-controlled rotary screw compressor positioned downstream the test chamber outlet. The air-cooled engines to be tested are fully exposed to the ambient conditions inside the test chamber, are able to aspirate the conditioned combustion air freely and release both exhaust gas and waste heat into the chamber environment. In order to control the power tool’s operation when the chamber is closed, an adaptive remote control system was specially developed. It enables automatic engine start-up by cable pull (e.g. for cold start testing), engaging the choke valve as well as operating the throttle lever automatically. This paper discusses the development process, the design, the operating limits of the climate and altitude simulation test bench as well as first tests on the reproducibility of the automatic start procedure, particularly important for future cold start investigations.

Martel, Artur, Scholl, Fino, Weierter, Dennis, Kettner, Maurice

Safety Analysis of an Airship Which Loses Lifting Gas from the Hull

2018-01-195410/30/2018

This study investigates the physical phenomena that affect a high-altitude airship in the presence of lifting gas losses from the hull. General atmospheric thermodynamics and basic physical principles are adopted to describe the behavior of an airship with envelope failures that generate buoyant gas dispersion or depressurisation phenomena. Overpressure that could grant to maintain some controllability during a large part of the descent is assessed by mean of the thermodynamic model of the envelope in the presence of gas losses. Optimisation of the inflation parameters is provided and the conditions for avoiding dangerous crashes on the ground and the potential recovery of a damaged vehicle, people and its payload. In particular, the requirements for a slow depressurisation is computed by the equilibrium with the atmosphere and then how can it be possible to sustain controlled navigation are determined. A key factor for security relates directly to the capability of preserving some airship balloon overpressure for the longest time possible. This condition can extend much the range of control. Complete forfeit conditions will be determined to demonstrate that airship cannot be anymore controllable below 20% of the initial altitude at which the failure has started. In some cases, specific manoeuvres could allow configuring the deflated balloon as a parachute, if coupled with adequate safety systems. This research about safety conditions will also be useful for designing safety systems. A general guideline for safety systems has been defined showing that airship if well created and well governed in emergency conditions will be much safer than any other aerial vehicle.

Trancossi, Michele, Pascoa, Jose, Cannistraro, Giuseppe

Combustion Behavior of n-Heptane, Isooctane, Toluene and Blends under HCCI Conditions in the Pressure-Temperature Diagram

2018-01-16849/10/2018

Homogeneous charge compression ignition (HCCI) experiments were run with the aid of a Cooperative fuel research (CFR) engine, operating at 600 rpm and under very lean conditions (ϕ = 0.3). This study seeks to examine the combustion behavior of different fuels by finding the pressure-temperature (p-t) conditions that instigate the start of combustion, and the transition from low temperature combustion to principal combustion. The pressure-temperature diagram emphasizes p-t conditions according to their traces through the compression stroke. In each fuel tested, p-t traces were examined by a sweep of the intake temperature; and for each experimental point, combustion phasing was maintained at top dead center by adjusting the compression ratio of the engine. In addition to the p-t diagram, results were analyzed using a compression ratio-intake temperature diagram, which showed the compression ratio required with respect to intake temperature. Pure n-heptane, isooctane and toluene were investigated first. The results showed that these three fuels ignited in accordance with their octane number. The compression ratio-intake temperature diagram shows that the compression ratio decreased linearly with increased intake temperature. The p-t diagram reveals that the combustion of n-heptane always reacted with low temperature heat release, while toluene always reacted with one main combustion. However, isooctane behavior is subject to change. Isooctane combustion displayed two stages of combustion with low intake temperature, but when intake temperature increased, the low temperature heat release disappeared and only the main combustion remained. Finally, ignition delays computed from a constant volume model were compared to experimental ignitions; the results suggested that another model was required. Second, an octane number 90 primary reference fuel (PRF90) with different volume fractions of toluene was investigated. Results in the compression ratio-intake temperature showed that the compression ratio decreased linearly, while the intake temperature increased for PRF90 without toluene. When low fractions of toluene were added to PRF90 (from 5% to 30%), higher compression ratios were required and the trend became non-linear. A slight change in the compression ratio at low intake temperature was observed; while a greater change in the compression ratio at high intake temperature was required due to the presence of low temperature combustion. Finally, high fractions of toluene (higher than 40%) quenched the low temperature combustion and linear behavior was again achieved. The pressure temperature diagram also shows similar trends, with a transition of the low temperature combustion which moved in accordance with the fraction of toluene in PRF90.

Masurier, Jean-Baptiste, Altoaimi, Omar, Mohammed, Abdulrahman, Waqas, Muhammad, Johansson, Bengt

Virtual 48 V Mild Hybridization: Efficient Validation by Engine-in-the-Loop

2018-01-04104/3/2018

New 12 V/48 V power net architectures are potential solutions to close the gap between customer needs and legislative requirements. In order to exploit their potential, an increased effort is needed for functional implementation and hardware integration. Shifting of development tasks to earlier phases (frontloading) is a promising solution to streamline the development process and to increase the maturity level at early stages. This study shows the potential of the frontloading of development tasks by implementing a virtual 48 V mild hybridization in an engine-in-the-loop (EiL) setup. Advanced simulation technics like functional mock-up interface- (FMI) based co-simulation are utilized for the seamless integration of the real-time (RT) simulation models and allow a modular simulation framework as well as a decrease in development time. As baseline, an existing and validated co-simulation consisting of a GT-POWER engine model, a SimulationX transmission model, and a dSPACE Automotive Simulation Models (ASM) vehicle dynamics model is used. A Simulink-based dual 12 V/48 V power net model is developed to extend the base model. The 48 V side is mainly composed of a belt-driven starter generator (BSG) that is directly connected to the combustion engine (P0 layout) and a 48 V lithium-ion (Li-ion) battery. The 48 V side is coupled via a bidirectional DC/DC to the 12 V absorbent glass mat (AGM) battery and the 12 V loads. In the next step, an engine test bench is coupled with the RT simulation by replacing the simulated combustion engine. Extensive tests are carried out on the EiL test bench, considering new legislative test requirements like WLTC (Worldwide harmonized Light vehicles Test Cycle) and RDE (real drive emission). The results show the great emission reduction potential of 48 V mild hybrids and proof that the frontloading-based EiL methodology is a promising solution to validate the system behavior with a heterogeneous cyber-physical test setup.

Klein, Serge, Griefnow, Philip, Guse, Daniel, Xia, Feihong, Andert, Jakob

Autoignition of Isooctane beyond RON and MON Conditions

2018-01-12544/3/2018

The present study experimentally examines the low-temperature autoignition area of isooctane within the in-cylinder pressure-in-cylinder temperature map. Experiments were run with the help of a Cooperative Fuel Research (CFR) engine. The boundaries of this engine were extended so that experiments could be performed outside the domain delimited by research octane number (RON) and motor octane number (MON) traces. Since homogeneous charge compression ignition (HCCI) combustion is governed by kinetics, the rotation speed for all the experiments was set at 600 rpm to allow time for low-temperature heat release (LTHR). All the other parameters (intake pressure, intake temperature, compression ratio, and equivalence ratio) were scanned, such as the occurrence of isooctane combustion. The principal results showed that LTHR for isooctane occurs effortlessly under high intake pressure (1.3 bar) and low intake temperature (25 °C). Increasing the intake temperature leads to the loss of the LTHR and therefore to a smaller domain on the pressure-temperature trace. In such a case, the LTHR domain is restricted from 20 to 50 bar in pressure and from 600 to 850 K in temperature. By slightly decreasing the intake pressure, the LTHR domain remains unchanged, but the LTHR tends to disappear, and finally, at 1.0 bar, the LTHR domain ceases to exist. When the equivalence ratio is moved from 0.3 to 0.4, the LTHR domain is delimited in the same range of pressure and temperature, but the start of combustion occurs slightly earlier for the same pressure-temperature trace. Similar conclusions were drawn regarding the variation of both intake pressure and temperature, except that few LTHR points were observed under 1.0 bar intake.

Masurier, Jean-Baptiste, Waqas, Muhammad, Sarathy, Mani, Johansson, Bengt

Development of a Simulation Tool for High Capacity Metal Foam Heat Exchanger with Phase Change Material

2018-01-07834/3/2018

Metal foam with their high porosity and heat storage capacity can be combined with phase change materials to be a powerful heat storage device. Numerical simulations of metal foam behavior can be challenging due to their complex geometric patterns necessitating high mesh requirements. Furthermore, simulations of the inner workings of a metal foam heat exchanger comprising of a large number of individual metal foam canisters can be impossible. The objective of the current work is to develop a computational model using a proprietary CFD tool Simerics-MP/Simerics-MP+® to simulate the workings of a metal foam heat exchanger with phase change element. A heat transfer coefficient capturing this heat transfer between wax and metal is used to formulate the “simplified” mixture model. The versatility of the proposed model is in the universality of its application to any shape or structure of metal foam. The computational model developed is tested to replicate the results of the 3D simulation. Very good agreements for the coolant temperature rise between the model and 3D simulation are obtained. Metal foam heat exchangers comprising of 89 such individual single metal foam canisters are simulated using the “simplified” model. Different arrangements of the single metal foam canisters to make up the metal foam heat exchanger are explored. Simulation results show pure steel has a better heat transfer performance, followed by metal foam canister with phase change material and finally aluminum. However, weight and other material considerations can make the metal foam canisters a practical alternative for effective heat storage.

Srinivasan, Chiranth, Slike, Jody, Wang, De Ming, Gao, Haiyang

A Lane-Changing Decision-Making Method for Intelligent Vehicle Based on Acceleration Field

2018-01-05994/3/2018

Taking full advantage of available traffic environment information, making control decisions, and then planning trajectory systematically under structured roads conditions is a critical part of intelligent vehicle. In this article, a lane-changing decision-making method for intelligent vehicle is proposed based on acceleration field. Firstly, an acceleration field related to relative velocity and relative distance was built based on the analysis of braking process, and acceleration was taken as an indicator of safety evaluation. Then, a lane-changing decision method was set up with acceleration field while considering driver’s habits, traffic efficiency and safety. Furthermore, velocity regulation was also introduced in the lane-changing decision method to make it more flexible. Afterwards, the polynomial trajectory planning method was matched up with this lane-changing decision-making method and simulations based on Matlab/Simulink were finally conducted to verify the method presented in this article. As the simulation results showed, adopting the lane-changing decision-making method based on acceleration field, the lane-changing measurements such as starting position, span and driving speed can be optimized with driver’s habits involved. At the same time, the vehicle safety can be well ensured.

Zhu, Bing, Liu, Shuai, Zhao, Jian

Modeling and Validation of 48V Mild Hybrid Lithium-Ion Battery Pack

2018-01-04334/3/2018

As part of the midterm evaluation of the 2022-2025 Light-Duty Vehicle Greenhouse Gas (GHG) Standards, the U.S. Environmental Protection Agency (EPA) developed simulation models for studying the effectiveness of 48V mild hybrid electric vehicle (MHEV) technology for reducing CO2 emissions from light-duty vehicles. Simulation and modeling of this technology requires a suitable model of the battery. This article presents the development and validation of a 48V lithium-ion battery model that will be integrated into EPA’s Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) vehicle simulation model and that can also be used within Gamma Technologies, LLC (Westmont, IL) GT-DRIVE™ vehicle simulations. The battery model is a standard equivalent circuit model with the two-time constant resistance-capacitance (RC) blocks. Resistances and capacitances were calculated using test data from an 8 Ah, 0.4 kWh, 48V (nominal) lithium-ion battery obtained from a Tier 1 automotive supplier, A123 Systems, and developed specifically for 48V mild hybrid vehicle applications. The A123 Systems battery has 14 pouch-type lithium-ion cells arranged in a 14 series and 1 parallel (14S1P) configuration. The RC battery model was validated using battery test data generated by a hardware-in-the-loop (HIL) system that simulated the impact of MHEV operation on the A123 systems 48V battery pack over U.S. regulatory drive cycles. The HIL system matched charge and discharge data originally generated by Argonne National Laboratory (ANL) during chassis dynamometer testing of a 2013 GM Chevrolet Malibu Eco 115V MHEV. All validation testing was performed at the battery test facility (BTF) at the U.S. EPA National Vehicle and Fuel Emissions Laboratory (NVFEL) in Ann Arbor, Michigan. The simulated battery voltages, currents, and state of charge (SOC) of the HIL tests were in good agreement with vehicle test data over a number of different drive cycles, and excellent agreement was achieved between RC model simulations of the 48V battery and HIL battery test data.

Lee, SoDuk, Cherry, Jeff, Safoutin, Michael, McDonald, Joseph, Olechiw, Michael

Development of a Cold Start Fuel Penalty Metric for Evaluating the Impact of Fuel Composition Changes on SI Engine Emissions Control

2018-01-1264

4/3/2018

The U.S. Department of Energy’s Co-Optimization of Fuels and Engines initiative (Co-Optima) aims to simultaneously transform both transportation fuels and engines to maximize performance and energy efficiency. Researchers from across the DOE national laboratories are working within Co-Optima to develop merit functions for evaluating the impact of fuel formulations on the performance of advanced engines. The merit functions relate overall engine efficiency to specific measurable fuel properties and will serve as key tools in the fuel/engine co-optimization process. This work focused on developing a term for the Co-Optima light-duty boosted spark ignition (SI) engine merit function that captures the effects of fuel composition on emissions control system performance. For stoichiometric light-duty SI engines, the majority of NOx, NMOG, and CO emissions occur during cold start, before the three-way catalyst (TWC) has reached its “light-off” temperature. This light-off temperature depends on the exhaust composition, which changes with fuel formulation. Thus, the time to achieve light-off, and therefore the cold start emissions, depends on fuel composition. Since the time to reach light-off must be minimized to meet emissions regulations, modern vehicles employ cold start strategies that intentionally release fuel energy into the engine exhaust to heat the TWC above the light-off temperature as quickly as possible. The fuel penalty associated with catalyst heating during cold start provides a link between fuel properties, emissions performance, and engine efficiency. This paper describes the derivation of the Co-Optima SI engine merit function term for emissions control, which is based on the cold start fuel penalty for catalyst heating and the catalytic light-off temperature for a particular fuel composition. It also discusses the process used for extracting cold start fuel penalties from chassis dynamometer data sets previously collected at ORNL. The form of the merit function term is simple, but it is only intended as a starting point for comparing the potential impacts of changes in fuel formulation on emissions control system performance.