bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visualization and Analysis of the Multiphase Flow in an Electromagnetically Driven Dosing Pump
Authors: Petzold Martin , Weber Jürgen , Dautry Etienne , Ohligschläger Olaf , Müller Axel 
Published: February 2014

Fluids with a high proportion of dissolved air lead to an increased air release in hydraulic components. Looking at the fluid flow in a piston pump, the resulting multiphase flow may affect its metering performance. To improve effects caused by cavitation, it is necessary to detect and analyze all critical flow areas in detail.
This paper presents investigations of the multiphase flow in an electromagnetically driven dosing pump. This type of pump is suitable for metering any kind of liquid in motor vehicles in a very precise manner. Using high speed camera equipment and transparent components for the displacement chamber, the presented experimental work gives a comprehensive insight into the most relevant cavitation effects in the pump. In addition, the pressure inside the displacement chamber is measured with the help of a miniature pressure sensor. By combination of measuring data and visual recordings, cavitation phenomena can be determined precisely, so that a profound understanding of the flow behavior in the pump is achieved.
The Influence of Passive Valve Characteristics on the Performance of a Piezo Pump
Authors: Henderson Jean-Paul , Plummer Andrew , Johnston D. Nigel , Bowen Chris 
Published: February 2014

In this study, a piezoelectric stack actuator is used to oscillate a piston in a single cylinder pump. The pump is intended to directly supply a hydraulic actuator for motion control, and power output of about 1kW is targeted. Flow rectification is achieved by the use of passive check valves. The valve resonant frequency is found to have a significant effect on output flow. The expected increase in pump flow rate with driving frequency has been confirmed in simulation to hold true in a certain frequency range only. In addition, check valve size and therefore orifice area has to be adequate in order not to prohibitively restrict flow. Valve spring stiffness and valve mass need to be simultaneously optimized for the area of the valve to achieve the highest flow rate.
Calculations indicate that there is a power limitation due to the high current demand and also a high temperature rise for a large continuously operated piezo stack. Thus the piezo pump appears more promising for smaller scale applications, and those that require intermittent power (i.e. a low duty cycle).
Command Feedback for Position Control of Hydraulic Machines
Authors: Elton Mark , Winck Ryder , Book Wayne 
Published: February 2014

Previous research has shown that operator performance of industrial machines is superior with position control rather than rate control, except for large-workspace and dynamically slow manipulators, which includes most hydraulic machinery. This paper describes an investigation to determine why position control leads to better performance than rate control except for with dynamically slow manipulators, in an effort to increase operator performance of mobile hydraulic equipment. It examines why dynamically slow systems are an exception to the general rule, and proposes a human-machine interface (HMI), called command feedback, that leads to position control having superior performance, even in these exceptional situations.
Thirty participants performed five tasks six times using one of five HMIs. A rate and a position controller were used to manipulate a dynamically fast system and a dynamically slow system that was designed to mimic the motion of hydraulic cylinders. A new HMI that provided real-time position feedback to the operator of his/her commanded position was applied to the position controller for the dynamically slow system. Task performance was measured and comparisons were made between position and rate control. The addition of the real-time position feedback to the dynamically slow system resulted in nearly identical performance with both controllers. From these results we conclude that position control is more intuitive for fast systems when human operators do not have the physical capability to control the velocity well with rate control, and that the intuitiveness of rate control for dynamically slow systems results from the lack of position feedback because of the machine’s speed of response. Command feedback can be used to elevate operator performance of hydraulic machinery.
Design Potentials of External Gear Machines With Asymmetric Tooth Profile
Authors: Devendran Ram Sudarsan , Vacca Andrea 
Published: February 2014

This paper describes the design, optimization and the performance potentials of external gear machines with asymmetric tooth profiles. Conventionally, the design of these machines is entirely based on symmetric involute profile. A design method has been developed to derive the tooth profiles based on a modified rack-cutter profile which is assumed to be used for manufacturing the gears with asymmetric involute surfaces and trochoidal fillet profiles.
The study is based on the simulation tool HYGESim (HYdraulic GEar machines Simulator) which is being developed and has been validated by the authors’ research group to accurately analyze the performance of the machine. For the purpose of this research, HYGESim was adapted to simulate the particular case of non-symmetric gear profiles.
A specific optimization procedure based on genetic algorithm was implemented to find the maximum performance of the new design, in terms of volumetric efficiency, fluid borne noise, internal pressure peaks and localized cavitation acting on the design parameters that characterize the tooth profile.
The results of the optimization process are compared to the current state of the art for external gear machines. This comparison show very high potentials for this new design principle, particularly concerning the reduction of the fluid borne noise.
Validation and Results of a Pseudo-Multi-Zone Combustion Trajectory Prediction Model for Capturing Soot and NOx Formation on a Medium Duty Diesel Engine
Authors: Bittle Joshua A. , Gao Zhiming , Jacobs Timothy J. 
Published: February 2014

A pseudo-multi-zone phenomenological model has been created with the ultimate goal of supporting efforts to enable broader commercialization of low temperature combustion modes in diesel engines. The benefits of low temperature combustion are the simultaneous reduction in soot and nitric oxide emissions and increased engine efficiency if combustion is properly controlled. Determining what qualifies as low temperature combustion for any given engine can be difficult without expensive emissions analysis equipment. This determination can be made off-line using computer models or through factory calibration procedures. This process could potentially be simplified if a real-time prediction model could be implemented to run for any engine platform — this is the motivation for this study.
The major benefit of this model is the ability for it to predict the combustion trajectory, i.e. local temperature and equivalence ratio in the burning zones. The model successfully captures all the expected trends based on the experimental data and even highlights an opportunity for simply using the average reaction temperature and equivalence ratio as an indicator of emissions levels alone — without solving formation sub-models.
This general type of modeling effort is not new, but a major effort was made to minimize the calculation duration to enable implementation as an input to real-time next-cycle engine controller Instead of simply using the predicted engine out soot and NOx levels, control decisions could be made based on the trajectory. This has the potential to save large amounts of calibration time because with minor tuning (the model has only one automatically determined constant) it is hoped that the control algorithm would be generally applicable.
Analysis and Resolution of Piston Pin Joint Tick Noise
Authors: Hall Chris , Chen Yu , Mian Omar 
Published: February 2014

A new measurement system and methodology has been developed which allows for direct measurement of the piston pin behavior of an internal combustion engine, particularly as it relates to pin joint ticking noise contributing to Noise Vibration and Harshness (NVH). Based on the measured dynamic of the piston pin during engine operation, the root cause of the pin joint ticking noise in this application was defined to be sticking of the pin at the end of the exhaust stroke which prevented pin lift. In order to better understand and mitigate this phenomenon, numerical simulation was conducted by means of Elasto Hydrodynamic Lubrication (EHL).
The output of this simulation showed that modifying the shape of the connecting rod pin bore by ovality has a significant effect on the pin motion and pin acceleration which could eliminate the pin joint tick noise. This improved pin bore shape was tested in the engine and confirmed to eliminate the pin joint ticking noise by manipulating the pin motion and disallowing piston pin sticking. Finally, an analysis of the newly developed methodology to root cause and solve pin joint ticking is compared to the prior methodology.
A New Physics-Based Misfire Detection Technique for a SI Engine
Authors: Boudaghi Kh. N. M. , Shahbakhti M. , Jazayeri S. A. 
Published: February 2014

Control and detection of misfire is an essential part of on-board diagnosis of modern SI engines. This study proposes a novel model-based technique for misfire detection of a multi-cylinder SI engine. The new technique uses a dynamic engine model to determine mean output power, which is then used to calculate a new parameter for misfire detection. The new parameter directly relates to combustion period and is sensitive to the engine speed fluctuations caused by misfire. The new technique only requires measured engine speed data and it is computationally viable for use in a typical ECU.
The new technique is evaluated experimentally on a 4-cylinder 1.6-liter SI engine. Three types of misfires are studied including single, continues, and multiple events. The steady-state and transient experiments were done for a wide range of engine speeds and engine loads, using a vehicle chassis dynamometer and on-road vehicle testing. The validation results show the new technique is capable to detect all the three types of misfire with up to 97 percent accuracy during steady-state conditions. The new technique is augmented with a compensation factor to improve the accuracy of the technique for transient operations. The resulting technique is shown to be capable of detecting misfire during both transient and steady-state engine conditions.
Combustion Characteristics of Diesel Spray Under Low O2 Concentration Condition
Authors: Azetsu Akihiko , Nagashima Youhei , Yamamoto Kei 
Published: February 2014

The spray combustion of diesel fuel under conditions of very low ambient O2 concentrations was examined in this study. The detailed combustion characteristics were evaluated using two different sets of experimental apparatuses. A high-temperature, high-pressure combustion vessel with dual observation windows was employed to visualize the spray flame. The sequential images were obtained by using a high-speed color video camera and were analyzed using the two color method to quantify the temporal variation of the two dimensional distribution of soot temperature and KL factor. Both the ambient O2 concentration and the CO2 mixing ratio were varied as experimental parameters. A second constant volume vessel with a smaller internal volume was also employed as an experimental apparatus to conduct analyses of heat release rates based on temporal variations of pressure.
Based on a series of systematic experiments, we confirmed that O2 concentration is the primary factor affecting both the ignition delay and combustion period, while the level of CO2 mixing has little effect. Decreasing O2 concentrations were associated with delays in the appearance of the luminous flame following the onset of light emission from OH radicals. The heat release rate study showed the possibility of the existence of endothermic reactions during this period. The flame temperature was observed to decrease as the O2 concentration decreased and as the CO2 ratio increased, resulting in reduced NOx emissions. The amount of soot inside the flame initially increased with decreasing O2 concentrations, but then decreased starting at an O2 concentration of approximately 11%, such that minimal amounts of soot were generated at very low O2 levels. Both visual observations and emissions measurements confirmed that the simultaneous reduction of NOx, soot and CO can be successfully achieved under very low O2 concentrations.
NS 999 Electric Switcher Update
Authors: Barbee Gibson , Westreich Philippe 
Published: February 2014

Norfolk Southern Railway Company (NS) is developing an all-electric switching locomotive, the NS 999, to provide a zero point source emission electric locomotive option for rail switching service. The original NS 999, unveiled in September 2009, suffered from poor battery management and challenging battery packaging. The rebuilt NS 999, anticipated in the 4th quarter 2013, will be powered by Axion Power’s PbC® batteries. The Axion PbC® batteries provide increased charge/discharge cycle life and charge acceptance compared to conventional Valve Regulated Lead–Acid (VRLA) batteries, as well as increased usable energy when configured in series as ‘long strings.’
NS and Axion will review the challenges of the initial NS 999 battery management system, improvements to the battery management system, and test results from the Norfolk Southern Hybrid Locomotive Simulator using Axion’s PbC® lead–carbon hybrid battery/supercapacitor. Axion will present test data showing the low variation in strings of PbC® batteries compared to VRLA while simulating locomotive switching. PbC® batteries have a unique charging curve, known as “concave down, increasing,” which allows the batteries to self-equalize in strings. This characteristic of PbC® batteries provides for simpler battery management and reduced maintenance charging, while increasing the usable energy available within the string.
The rebuilt experimental locomotive NS 999 will use Axion’s PbC® lead–carbon batteries for the energy storage system to power locomotive switching and recover braking energy. If this research is successful, a zero point source emission electric locomotive could provide an option to reduce emissions in urban non-attainment areas and reduce dependence on petroleum. The NS 999 electric switcher is the first step to the ultimate goal of recovering braking energy from high power conventional diesel locomotives.
Design of a Multi-Use, Highly Efficient Intermodal Container System
Authors: Gorbunov Maksym 
Published: February 2014

This paper details the design of a shipping container concept with a purpose of being not only highly efficient in transport but also after arrival. In order to reduce mass while also increasing the ability to carry heavier loads, Lightweight structures and materials are employed instead of simple steels or cast iron used in current designs. The second goal of the design was to create a weld free structure that can be easily assembled and disassembled without the need for special labor and skills saving time, space and resources when shipping empty container or storing containers that are not in use. Shipping containers often clutter construction sites and temporary establishments like concerts and flea markets. By being able to break down and efficiently store containers businesses in charge of these temporary establishments can save valuable real estate and run much more efficiently.
Another design feature is creating an entirely modular system. Each container is made from completely interchangeable parts that can be swapped in and out for ones that have different function like container variations that provides insulation or active temperature or humidity control for temperature sensitive products or high security configurations for hazardous materials or expensive goods. In order to provide such interchangeability, the frame is designed to be strong and rigid enough to be able to handle the required loads without relying on wall plates. The combination of these design points leads to a transportation system that can not only be deployed using existing intermodal infrastructure but can serve a secondary purpose once it arrives at its destination. Because the containers are modular and highly versatile, they can be assembled into large floor space, multistory structures. Containers and trailers normally used as office space at construction sites are cramped, uncomfortable and very unsightly. Using this system, large two story office space of several thousand square feet can be erected using no more than a dozen containers. The modular walls can be used to swap in ceiling or wall panels that let in natural light, harness solar power or allow plumbing systems, electrical wiring, thermal insulation or ventilation. Because of the weld-free design and ultra-lightweight components, structure assembly and disassembly is simple with unskilled labor and common tools. This is especially important because the most impactful application of this system could be in disaster relief. Single containers can be used as substitutes for single family homes and large container assemblies can be used to create anything kind of community use structure from shower clusters to temporary schools to dining halls to administrative buildings creating a sustainable temporary community.
Development of Railroad Wheel Rim Axial Residual Stress in Heavy Axle Load Service
Authors: Lonsdale Cameron , Oliver John , Maram Rama Krishna , Cummings Scott 
Published: February 2014

Vertical split rim (VSR) failures remain a failure mode for wheels in North America, and are of concern to wheel manufacturers and railroads alike. Both forged and cast wheels have suffered VSRs in service. Extensive testing during the last several years, using x-ray diffraction techniques, has shown the axial residual stress pattern within the railroad wheel rim is significantly different for new AAR Class C wheels vs. AAR Class C wheels that have failed due to a VSR, and non-failed AAR Class C wheels that have been operating in service. VSRs almost always begin at areas of tread damage, resulting from shelling or spalling, and cracking propagates into the rim section under load. At the rim locations tested, the as-manufactured wheels have a relatively “flat” axial residual stress profile, compressive but near neutral, caused by the rim quenching operation, while wheels that have been in service have a layer of high axial compressive stress at the tread surface, and a balancing zone of axial tensile stress underneath. The magnitude and direction of this axial tensile stress is consistent with the crack propagation of a VSR failure. When cracks from tread surface damage propagate into this subsurface axial tensile zone, a VSR can occur under sufficient additional service loading, such as loads caused by in-service wheel/rail impacts from tread damage. Further, softer Class U (untreated) wheels, removed from service and tested, were found to have a balancing axial tensile stress layer deeper below the tread surface than that found in used Class C wheels.
This paper describes recent x-ray diffraction testing to measure the axial residual stress profile in wheel rims operated in the Facility for Accelerated Service Testing (FAST) train at the Transportation Technology Center (TTC), in Pueblo, CO. The goal of the testing was to determine the development rate and magnitude of wheel rim axial residual stress, as a function of known load and service mileage. Four new Class C wheelsets and four new Class U wheelsets were placed in service under the FAST train, and these wheelsets were subsequently removed at various mileage levels for evaluation. Two radial rim slices were cut from each wheel at each mileage level, and x-ray diffraction was used to measure the axial residual stress within the wheel rim section. The last two Class C wheelsets and last two Class U wheelsets were also exposed to an extended drag braking event at FAST, where wheel treads were heated by tread braking. The authors describe the testing and discuss the axial residual stress results in detail, with emphasis on implications for service.
Evaluation of image guided motion management methods in lung cancer radiotherapy
Authors: Zhuang Ling , Yan Di , Liang Jian , Ionascu Dan , Mangona Victor , Yang Kai , Zhou Jun 
Published: February 2014

Purpose:To evaluate the accuracy and reliability of three target localization methods for image guided motion management in lung cancer radiotherapy.Methods:Three online image localization methods, including (1) 2D method based on 2D cone beam (CB) projection images, (2) 3D method using 3D cone beam CT (CBCT) imaging, and (3) 4D method using 4D CBCT imaging, have been evaluated using a moving phantom controlled by (a) 1D theoretical breathing motion curves and (b) 3D target motion patterns obtained from daily treatment of 3 lung cancer patients. While all methods are able to provide target mean position (MP), the 2D and 4D methods can also provide target motion standard deviation (SD) and excursion (EX). For each method, the detected MP/SD/EX values are compared to the analytically calculated actual values to calculate the errors. The MP errors are compared among three methods and the SD/EX errors are compared between the 2D and 4D methods. In the theoretical motion study (a), the dependency of MP/SD/EX error on EX is investigated with EX varying from 2.0 cm to 3.0 cm with an increment step of 0.2 cm. In the patient motion study (b), the dependency of MP error on target sizes (2.0 cm and 3.0 cm), motion patterns (four motions per patient) and EX variations is investigated using multivariant linear regression analysis.Results:In the theoretical motion study (a), the MP detection errors are −0.2 ± 0.2, −1.5 ± 1.1, and −0.2 ± 0.2 mm for 2D, 3D, and 4D methods, respectively. Both the 2D and 4D methods could accurately detect motion pattern EX (error < 1.2 mm) and SD (error < 1.0 mm). In the patient motion study (b), MP detection error vector (mm) with the 2D method (0.7 ± 0.4) is found to be significantly less than with the 3D method (1.7 ± 0.8,p < 0.001) and the 4D method (1.4 ± 1.0, p < 0.001) using paired t‐test. However, no significant difference is found between the 4D method and the 3D method. Based on multivariant linear regression analysis, the variances of MP error in SI direction explained by target sizes, motion patterns, and EX variations are 9% with the 2D method, 74.4% with the 3D method, and 27% with the 4D method. The EX/SD detection errors are both < 1.0 mm for the 2D method and < 2.0 mm for the 4D method.Conclusions:The 2D method provides the most accurate MP detection regardless of the motion pattern variations, while its performance is limited by the accuracy of target identification in the projection images. The 3D method causes the largest error in MP determination, and its accuracy significantly depends on target sizes, motion patterns, and EX variations. The 4D method provides moderate MP detection results, while its accuracy relies on a regular motion pattern. In addition, the 2D and 4D methods both provide accurate measurement of the motion SD/EX, providing extra information for motion management.