bluuebunny/crossref_metadata_2025 huggingface dataset:
A CFR1065-Compliant Transportable/On-Road Low Emissions Measurement Laboratory With Dual Primary Full-Flow Dilution Tunnels
Authors: Wu Yuebin , Carder Daniel , Shade Benjamin , Atkinson Richard , Clark Nigel , Gautam Mridul
Published: August 2009

In 2007, certification standards for heavy duty diesel particulate matter (PM) emissions were reduced from 0.1g/bhp-hr to 0.01g/bhp-hr, representing an order of magnitude reduction in pollutant level. Coincident with these standards revisions are refinements to test procedures that target reductions in measurement uncertainties. The 2007 U.S. Environmental Protection Agency (US EPA) specifications, as defined in 40 CFR parts 86, and US EPA 2010 specifications, as defined in CFR 1065, require significant updates to established laboratory measurement systems and test procedures. Moreover, additional regulatory standards pertaining to in-use compliance of heavy duty diesel engines will significantly impact the future of heavy duty diesel emissions measurement. As a result of the reduced emission production levels, demand for ‘real-world’ emissions measurements, and subsequent development and evaluation of on-board emissions measurement systems, West Virginia University’s Center for Alternative Fuels, Engines, and Emissions (CAFEE) has designed and constructed, with support from the U.S. Department of Energy (DOE), the ‘next level’ transportable dual primary full-flow dilution tunnel emissions measurement laboratory. The objective of this project was to build a mobile emissions measurement laboratory, of engine test cell quality, that is capable of measuring regulated and non-regulated emissions, and meets US EPA 2007 and 2010 specifications. A thirty-foot long cargo container was constructed to house a portable emissions measurement facility, comprised of a High Efficiency Particulate Air (HEPA) primary dilution unit, two primary full-flow dilution tunnels, a subsonic venturi, a secondary particulate matter sampling system, a gaseous emissions analytical bench instrumentation system, a computer based data acquisition (DAQ) and control system, full air conditioning and ventilation system, and chassis dynamometer control systems. Dual tunnels, of 18 inches ID and 20 feet long provide dedicated measurement capability for both lower PM vehicles, as well as legacy diesel fueled vehicles. This provision reduces tunnel history effects between test programs which address differing exhaust composition and PM loading. The laboratory grade analytical system can be transported to virtually any location with a demand for emissions testing, either with or without WVU’s transportable medium or heavy duty chassis dynamometers. Alternatively, the system can be loaded onto a flatbed trailer in order to test emissions while a vehicle is operated over the road. This paper describes each sub-system of this transportable laboratory in the aspect of specifications and design considerations, and presents results of qualification tests on the laboratory.
A Six Sigma Approach to Improving Exhaust Valve Reliability in a Stoichiometric Natural Gas Engine
Authors: Feldner Mike
Published: August 2009

Six-sigma is a data-based problem solving methodology that is used to reduce production variation in order to improve product quality. It has typically been used by successful companies to optimize operational processes and assist with waste reduction. Over the past several years, Dresser Waukesha has incorporated Six-sigma tools into several different areas of product engineering. This paper will illustrate how Dresser Waukesha has used Six-sigma tools to assist with product design and validation processes for reliability improvements of exhaust valves. Several specific examples of Six-sigma tools will be provided as the improvement project follows the DMAIC process. The scope of this discussion will be limited to using Six-sigma tools in the measure, analyze and improve phases of the project, where product engineering is most involved. In the measure phase, design of effective ratings charts that transform subjective visual assessments into quantifiable data for purposes of evaluating the effects of specific design parameters on critical wear metrics will be shown. Also, gauge repeatability & reproducibility for precise wear measurements will be discussed. During the analyze phase, the use of box plots, design of experiments tools and ANOVA statistical analyses for material selection, valve guide length and stem clearance determination will be explained. During the improve phase, an example of using the Pugh Matrix to compare different analytical concepts will be provided. Finally, an evaluation methodology that uses statistical capability analyses instead of traditional analyses of individual valve wear to validate long-term reliability and to minimize required test time will be explained.
High Resolution Scalar and Velocity Measurements in an IC Engine
Authors: Petersen B. R. , Heim D. M. , Ghandhi J. B.
Published: August 2009

High resolution planar laser-induced fluorescence (PLIF) and particle-image velocimetry (PIV) measurements were acquired during the intake stroke in a motored engine to investigate the mixing behavior of in-cylinder flows. The data were analyzed to determine the scalar energy and kinetic energy spectra, which were used to find the corresponding dissipation spectra. The results were compared to a model turbulent spectrum. The scalar energy and scalar dissipation spectra were shown to be resolved through the full dissipation range, enabling the determination of the Batchelor / Kolmogorov length scale, and agreed well with the model turbulent spectrum at all but the highest wavenumbers where the effects of random noise were present. The 2% point in the scalar dissipation spectra was used to estimate the Batchelor scale, which was found to be approximately 32 μm. The PIV data, which had a 675 μm interrogation region, were used to calculate a one-dimensional kinetic energy spectrum. The kinetic energy spectrum agreed well with the scalar energy spectrum and the model spectrum up to wavenumbers corresponding to approximately 2× the PIV interrogation region size. For the present measurements, this meant that the PIV data were not able to resolve the peak in the dissipation spectrum, i.e. the full high-wavenumber part of the inertial subrange.
An Experimental and Simulation Study of Increases in Fuel Consumption and NOX Emissions in a Biofueled Diesel Engine
Authors: Adi Gayatri , Hall Carrie , Snyder David , Bunce Michael , Satkoski Christopher , Koehler Jeremy , Kumar Shankar , Shaver Gregory
Published: August 2009

Alternative fuel vehicles are gaining importance as a means of reducing petroleum dependence. One attractive option is biodiesel, a renewable diesel fuel produced from plant or animal fats, since it significantly reduces carbon monoxide, unburned hydrocarbon, and particulate matter emissions as well as carbon dioxide when considered on a full life cycle basis. However, biodiesel combustion also typically results in increased fuel consumption and nitrogen oxide (NOx) emissions relative to petroleum diesel. In order to determine the cause of and develop mitigation strategies for increased biodiesel fuel consumption and NOx emissions, an accurate simulation model was developed and validated. Key fuel properties as well as ignition delay characteristics were implemented in a previously validated whole engine model to reflect soy-biodiesel fuel. The model predictions were within 5% of experimental results for most values at the three operating points. Using this biodiesel model, the “biodiesel NOx effect” was linked to the near stoichiometric equivalence ratios for biodiesel.
Transient EGR in a Long-Route and Short-Route EGR-System
Authors: Reifarth Simon , A˚ngstro¨m Hans-Erik
Published: August 2009

The use of EGR to lower NOX-emissions from Diesel engines is a well-documented method. Recently, more and more research is done on alternative EGR routing systems such as long-route EGR. To reach future emission legislation goals it is not sufficient to focus on steady-state driving. The emission peaks during the transient parts of driving cycles are gaining importance. It is therefore interesting to analyze the EGR-flow in transients for different configurations of the EGR system. In this work, a 1-D simulation is performed in GT-Power for a Euro 4 passenger car diesel engine equipped with cooled short-route EGR and a variable geometry turbine. For calibration of the simulation, load transients were measured including the measurement of transient EGR-rates using a fast CO2-analyzer and cylinder pressure to obtain heat-release data. While the transient heat-release rates are used as an input for the combustion-simulation, the EGR response measurements are used as a reference for calibration of the EGR-system and its components. A long route EGR system and a short-route EGR system are then simulated and compared, focusing on transient response, availability of EGR during the transient and the fuel consumption in steady state. It is shown that the long-route system has advantages in both steady-state and transient driving conditions. In steady state it can decrease fuel consumption, in transient it can provide EGR without negative effect on the transient response.
Implementation of a Finite-Element Based Mesh Motion Technique in an Open Source CFD Code
Authors: Brusiani Federico , Bianchi Gian Marco , Lucchini Tommaso , D’Errico Gianluca
Published: August 2009

Nowadays, Computational Fluid Dynamic (CFD) codes are widely used in different industrial fields. Although hardware and numerical model improvements, the mesh generation remains one of the key points for a successful CFD simulation. Mesh quality is influenced by the adopted mesh generator tool and, after all, by the designer’s experience and it becomes very important when moving meshes are required. In fact, mesh skewness, aspect ratio, and non-orthogonality have to be controlled during the deforming process since their wrong evolution could produce an unphysical behavior of the computed flow field. Mesh motion could be performed by different strategies: dynamic smoothing operation and dynamic re-meshing operation, are, today, two of the mainly used approaches. All of them can be combined to guarantee the correct reproduction of motion profile and a good mesh quality level. In this context, the authors have implemented a moving mesh methodology in the Open Source CFD code OpenFOAM®. A multiple number of meshes is used to cover the whole simulation period, and the grid point motion is accommodated by an automatic mesh motion techinque with polyhedral cell support. The Laplace equation is chosen to govern mesh motion. This guarantees that an initial valid mesh remains valid for arbitrary boundary motion. Mesh to mesh interpolation is performed by using a cell based, distance weighted interpolation technique. The proposed approach was tested on a real IC-engine geometry. In particular, the mesh quality evolution during motion, the numerical results and the computational costs were evaluated.
Engine Performance and Emissions Formation for RME and Conventional Diesel Oil: A Comparative Study
Authors: Yang Junfeng , Johansson Monica , Golovitchev Valeri
Published: August 2009

A comparative study on engine performance and emissions (NOx, soot) formation has been carried out for the Volvo D12C diesel engine fueled by Rapeseed Methyl Ester, RME and conventional diesel oil. The combustion models, used in this paper, are the modifications of those described in [1–2]. After the compilation of liquid properties of RME specified as methyl oleate, C19H36O2, making up 60% of RME. The oxidation mechanism has been compiled based on methyl butanoate ester, mb, C5H10O2 oxidation model [3] supplemented by the sub-mechanisms for two proposed fuel constituent components, methyl decanoate, md, C11H22O2, n-heptane, C7H16, and soot and NOx formations reduced and “tuned” by using the sensitivity analysis. A special global reaction was introduced to “crack” the main fuel into constituent components, md, mb and propyne, C3H4, to reproduce accurately the proposed RME chemical formula. The sub-mechanisms were collected in the general one consisting of 99 species participating in 411 reactions. The combustion mechanism was validated using shock-tube ignition-delay data at diesel engine conditions and flame propagation speeds at atmospheric conditions. The engine simulations were carried out for Volvo D12C engine fueled both RME and conventional diesel oil. The numerical results illustrate that in the case of RME, nearly 100% combustion efficiency was predicted when the cumulative heat release, was compared with the RME LHV, 37.2 kJ/g.. To minimize NOx emissions, the effects of 20–30% EGR levels depending on the engine loads and different injection strategies were analyses. To confirm the optimal engine operation conditions, a special technique based on the time-transient parametric φ-T maps [4] has been used.
The Study of Residence Time and Flow Rate of Lubricating Oil Through the Top Ring Zone of a Gasoline Engine
Authors: Lee Peter M. , Priest Martin , Stark Moray , Taylor Robert Ian
Published: August 2009

With the ever increasing demand on lubricant manufacturers to improve fuel economy, fuel economy retention and increase the drain intervals of their lubricants there is an increasing need to understand which factors effect the degradation of the lubricant in the sump. The harsh conditions in the ring pack have been shown to be responsible for the majority of the lubricant degradation in the engine. Therefore in this investigation the flow rate of lubricant through, and residence time of lubricant in, the top ring zone of a gasoline engine with respect to load and speed has been experimentally measured. An initial effect of the lubricant viscosity on these parameters has also been investigated. The theory and experimental methods are described before the experimental results are presented and discussed. The work has shown that the overall effect of engine speed on sump lubricant degradation is nominal, and that the level of sump degradation increases with increasing engine load.
Effects of Blending Gasoline With Ethanol and Butanol on Engine Efficiency and Emissions Using a Direct-Injection, Spark-Ignition Engine
Authors: Cooney Christopher , Wallner Thomas , McConnell Steve , Gillen Jeffrey C. , Abell Clint , Miers Scott A. , Naber Jeffrey D.
Published: August 2009

The new U.S. Renewable Fuel Standard requires an increase of ethanol and advanced biofuels to 36 billion gallons by 2022. Due to its high octane number, renewable character and minimal toxicity, ethanol was believed to be one of the most favorable alternative fuels to displace gasoline in spark-ignited engines. However, ethanol fuel results in a substantial reduction in vehicle range when compared to gasoline. In addition, ethanol is fully miscible in water which requires blending at distribution sites instead of the refinery. Butanol, on the other hand, has an energy density comparable to gasoline and lower affinity for water than ethanol. Butanol has recently received increased attention due to its favorable fuel properties as well as new developments in production processes. The advantageous properties of butanol warrant a more in-depth study on the potential for butanol to become a significant component of the advanced biofuels mandate. This study evaluates the combustion behavior, performance, as well as the regulated engine-out emissions of ethanol and butanol blends with gasoline. Two of the butanol isomers; 1-butanol as well as iso-butanol, were tested as part of this study. The evaluation includes gasoline as a baseline, as well as various ethanol/gasoline and butanol/gasoline blends up to a volume blend ratio of 85% of the oxygenated fuel. The test engine is a spark ignition, direct-injection, (SIDI), four-cylinder test engine equipped with pressure transducers in each cylinder. These tests were designed to evaluate a scenario in terms of using these alcohol blends in an engine calibrated for pump gasoline operation. Therefore no modifications to the engine calibration were performed. Following this analysis of combustion behavior and emissions with the base engine calibration, future studies will include detailed heat release analysis of engine operation without exhaust gas recirculation. Also, knock behavior of the different fuel blends will be studied along with unregulated engine out emissions.
Saving Fuel in Large-Bore Natural Gas Engines Using Cylinder-by-Cylinder Electronic Fuel Control: A Case Study
Authors: McCoy James J.
Published: August 2009

This paper describes the method used to retrofit a modern, computer-controlled fuel system to older, large-bore pipeline engines in order to improve the reliability of the engine, while also improving the fuel efficiency of the engine. In cases where the engines run in off-load condition (and many do), it is possible to improve fuel efficiency by from five to twenty-five percent, and the engine runs much smoother, reducing the mechanical stress on the engine. This system does not require expensive fuel valves that can withstand the heat and pressure of the combustion chamber, and thus is much more cost effective. With the developed software algorithms, the computer decides when, and how many, cylinders to disable, and when to reactivate. Of the approximately eight thousand low-speed, non-turbocharged stationary engines in pipeline service in North America, approximately half could benefit from this system, and will enable these engines to run for many more years in a much more efficient manner.
Effects of B20 on Combustion, Emissions and Performance of a Light-Duty Diesel Engine
Authors: Peterson Amy M. , Lee Po-I , Lai Ming-Chia , Wu Ming-Cheng , DiMaggio Craig L.
Published: August 2009

This paper compares 20% bio-diesel (B20-choice white grease) fuel with baseline ultra low sulfur diesel (ULSD) fuel on the performance of combustion and emissions of a light-duty 4-cylinder 2.8-liter common-rail DI diesel engine. The results show that operating the engine in the Low Temperature Combustion (LTC) regime produces lower PM and NOx with a slight penalty in fuel consumption, THC, and CO emissions. B20, in general, produces less soot. A slight increase in NOx emissions is shown with B20 compared to ULSD, with an exception at the high speed point where B20 has lower NOx values. In addition, the performance and emission characteristics are investigated as a function of the ECU injection strategy. The addition of pilot injections is found to effectively reduce combustion noise and extends the injection retard window to reach LTC combustion regimes with acceptable noise level for LD diesel engines.
Mass Transfer Coefficients for a Bingham Fluid and Water With and Without Anti-Foam Agents
Authors: Leishear Robert A. , Guerrero Hector N. , Restivo Michael L. , Sherwood David J.
Published: August 2009

The equations describing mass transfer coefficients are rather concise, but experimental data is required to determine the coefficients. Here, mass transfer rates were measured in a large scale system, which consisted of an 8.4 meter tall by 0.76 meter diameter column containing one of three fluids: water with an anti-foam agent, water without an anti-foam agent, and a Bingham plastic fluid, referred to as AZ101 simulant. The Bingham fluid differed from water since it required an applied yield stress to initiate flow. Newtonian fluids, like water, have a zero yield stress. Each of the fluids was saturated with oxygen, and the oxygen was removed from solution as air bubbled up, or sparged, through the solution from the bottom of the column. Air sparging was supplied by a single pipe which was co-axial to the column. The decrease in oxygen concentration was recorded, and the oxygen measurements were then used to determine the mass transfer coefficients to describe the rate of oxygen transfer from solution. Mass transfer data for 24 different test conditions were determined. Superficial sparging velocities of 2, 5, and 10 mm/second were applied to each of the simulants at three different column fill levels, where the superficial velocity is defined as the average volumetric flow rate divided by the liquid surface area in the column. Mass transfer coefficient test results are presented herein for each test combination of superficial velocity and fluid level.
Development of a Novel Method for Dry Grinding of Soft Steel
Authors: Tawakoli Taghi , Azarhoushang Bahman
Published: August 2009

Compared to other machining processes, grinding involves high specific energy. This energy mainly transforms to heat which makes detrimental effects on surface integrity as well as tool wear. In dry grinding, as there is no cutting fluid to transmit generated heat in the contact zone, reducing grinding energy and grinding forces are crucial. Presented in this paper are some of the promising results of the systematic research work carried out by the authors in order to come closer to the goal of pure dry grinding. A new method to reduce the heat by superimposing ultrasonic vibrations on workpiece movement is presented. The obtained results show that the application of ultrasonic vibration can eliminate the thermal damage on the workpiece and decrease the grinding forces considerably. A decrease of up to 60% of normal grinding forces and up to 40% of tangential grinding forces has been achieved.
Thermal Response Analysis of Large Aperture Optical Components
Authors: Zhou Yi , Lin Dong-hui , Zhou Hai , Zhang Jun-wei , Wang Shi-long
Published: August 2009

This paper analyze the deformation of large aperture optical components under the thermal load based on the finite element model developed using the ANSYS software, which are used for inertia confinement fusion (ICF) experiments. High precision sensors are used to measure the temperature around the optical components in the target building and to form the temperature changing curve. The biggest temperature change is 0.3°C during 2 hours based on the measurement. The change is then loaded on the finite element model of a typical large aperture optical component to get the deformation of the optical component. The results indicate that the deformation of the optical component can satisfy the stability requirement in the current environment. Meanwhile, the deformation of the optical component is calculated for different temperature changes and the results show that the deformation of the optical component have a direct relationship with the change of temperature.
Synthesis of CFD Analyses and Experiments in Developing a Thermal Network Model of a Simulated Heat Spreader Panel
Authors: Ishizuka Masaru , Nakagawa Shinji , Yoshida Tatsuro , Nakayama Wataru
Published: August 2009

The object of the present study is a simulated heat spreader panel (80 × 100 × 0.8 mm3) which carries five distributed heat sources and a finned heat sink near one of its corners. The panel thickness is designed to minimize temperature variation over the heat sources. The panel and the wrapping insulation possess geometric and thermal characteristics commonly found in thin electronic products. Thin configuration increases the sensitivity of internal temperature to the variation of external thermal environment; that is, a significant level of uncertainties should be expected in the thermal design of such systems. The present study aims at the development of a methodology for thermal analysis of such thin systems. Uncertainties in the thermal environment demand the coverage of a wide range of relevant parameters by the analysis, and computations can be performed most efficiently with a thermal network model. To achieve the stated goal we performed CFD simulations and the experiments, and reduced the results into a thermal network model.
Cerebral Blood Vessel Rupture During Head Impacts: A Parametric Study on Properties of SAS Trabeculae and Pia Mater
Authors: Zoghi-Moghadam M. , Sadegh A. , Saboori P.
Published: August 2009

Blunt head impacts cause relative motion between the brain and skull. This increases the normal and shear stresses in the (skull/brain) interface region, which leads to the rupture of cerebral blood vessels and in particular bridging veins. Mechanical properties of meningeal layers, in particular, subarachnoid space (SAS) trabeculae and the pia mater are not well established in the literature and could have a wide range depending on an individual. In our previous studies, knowing that SAS trabeculae and pia mater are collagen-based structures, these mechanical properties have been estimated using the properties of similar collagen based tissues. However, recent study Xin Jin et al. (2008), suggests that the mechanical properties of trabeculae and the pia matter are significantly less than a collagen-based tissue. Therefore, the goal of this study is to investigate the effect of the mechanical properties of these tissue on the stress and strain of the neighboring tissues when the head is subjected to a blunt impact. Specifically, the objectives of this study is to determine the stress/strain changes of the cerebral blood vessels as a function of the mechanical properties of the SAS trabeculae and pia mater, when the loading and the boundary conditions of the local model are kept the same. Note that the variation of the properties of these tissues affects the failure of cerebral blood vessels which leads to traumatic brain injury.
Thermodiffusion, Marangoni and Gravity Driven Convections in a Liquid Layer Overlying a Porous Layer: Lateral Heating Conditions
Authors: Rahman M. A. , Saghir M. Z.
Published: August 2009

In this paper, we study the onset of thermal convection in a liquid layer overlying a porous layer, where the whole system being laterally heated. The non-linear two-dimensional Navier Stokes equations, the energy equation and the mass transfer equation are solved for the liquid layer. Instead of Navier Stokes equations, the Brinkman model is used for the porous layer. The partial differential equations are solved numerically using the finite element technique. Three cases are presented in this paper. In the first case, the gravity driven buoyancy convection is studied. In the second case, the surface tension is assumed to vary linearly with temperature, therefore the existence of Marangoni convection. To analyze the Marangoni convection, we consider microgravity condition. Different aspect ratios as well as the thickness ratios are studied in detail for both the first and second cases. In the third case, diffusion and the thermodiffusion between two binary fluids with two different compositions in liquid and porous layer is studied.
Burn Rate Analysis of an Ethanol-Gasoline, Dual Fueled, Spark Ignition Engine
Authors: Mittal M. , Zhu G. , Schock H. J. , Stuecken T. , Hung D. L. S.
Published: August 2009

An experimental study is performed to investigate the combustion characteristics of an ethanol-gasoline, dual fueled, single cylinder spark ignition (SI) engine. A dual fuel injection system with both Direct-Injection (DI) and Port-Fuel-Injection (PFI) is used in this work. The performance of PFI-E85 and DI-gasoline, and PFI-gasoline and DI-E85 systems is presented. E85 is a blend of 85% ethanol and 15% gasoline by volume. In each test, the percentage of E85 is varied from 100 (0% gasoline) to 0 (100% gasoline) to compare the various cases. PFI-gasoline and DI-gasoline (PFI & DI-gasoline) results are also presented to provide a baseline for comparison. The cycle-to-cycle variability is presented using coefficient of variation (COV) of indicated mean effective pressure (IMEP). Mass fraction burned (MFB) and burn duration are determined from the analysis of measured in-cylinder pressure data. The well known Rassweiler and Withrow method (Model 1), with a new linear model for the polytropic index, is used to obtain the MFB curves. The differences are presented for the net pressure method (Model 2) to evaluate the burn rates. It is found that combustion is faster with the increase in PFI percentage for all the three setups with dual fuel injection. The PFI-E85 and DI-gasoline system showed that the burn duration decreases significantly with the increase in PFI percentage; however, the PFI-gasoline and DI-E85 system showed only slight differences with the increase in PFI percentage. Model 2 showed good agreement with Model 1 at high load conditions; however, it predicts slower combustion at light load conditions.
An Object-Oriented Contact Modelling Framework for Robotics
Authors: Gonthier Yves , Lange Christian
Published: August 2009

An object-oriented framework that facilitates the creation of contact models based on compliance is introduced. Contact models are created by adding contact model components to a standard container class. The geometric components can readily be implemented for objects with simple geometries. The volumetric contact model is then proposed to handle complex objects. It can be used as a general-purpose tool to model contact between objects of any shapes. Numerical simulation results are presented.
Possibility of Fatigue Crack Extension Under Cyclic Large Compressive Stress by Medium Frequency Induction Hardening
Authors: Sakamoto Haruo , Ishiduka Hiromichi , Akama Makoto , Tanaka Kenichi
Published: August 2009

Induction hardened axles have been used since the start of the Shinkansen (Japanese Bullet train) service in 1964. Axles are subjected to cyclic loading, and induction hardened axles are used under cyclic compressive stress conditions because of the large compressive stress state caused by induction hardening along the axle surface. Japanese Railways regularly inspect its axles, and if any crack larger than 0.15 mm in depth is found, the axle is taken out of service. The compressive stress is around −500 MPa, and magnetic particle inspection is conducted at intervals of 2.2×108 and 4.4×108 rotation. The issue of whether or not a crack more than 0.15 mm in depth will propagate under cyclic large compressive stress conditions is of great importance from the viewpoint of railroad safety. From the above mentioned background, a literature survey and experiment of fatigue crack extension under a cyclic large compressive stress condition were conducted. The results show that the crack did extend in the range of around 3.6–5.0×108 cycles under the condition of −500∼0 MPa cycle. Elastic-perfectly plastic stress analysis was also conducted to understand the possibility of tensile residual stress origination, which is considered to be a cause of extension. The analysis of −500∼0 MPa cycle showed that a large tensile stress of about 89.5 MPa originated at the crack tip when unloading. Whereas, the analysis of −560∼−440 MPa cycle for actual maximum stress in the field showed compressive when unloading.
Design and Development Education Using Leg/Wheel Hybrid Movement Mechanics for Rough Surfaces
Authors: Sakamoto Haruo
Published: August 2009

Academic departments should engage in education, research, and contributions to society. In this report, the author describes the educational activities of design and production, with a focus on movement mechanics using COSMOS motion software. Engineers in mechanical engineering are required to design and produce new mechanical products as well as to create new technologies related to those products. Moreover, because the field of robotics is rapidly growing, the study of movement mechanics is necessary because of its important role in such robotic products. In this report, graduate-level laboratory work for the design and development of aerospace products is described. Specifically, this report focuses on a robot for moving across rough surfaces that incorporates hybrid robot mechanics using wheels and legs for surface search.
A New Pressure Boundary Condition of Lattice Boltzmann Method (LBM) for Fully Developed Pressure-Driven Periodic Incompressible Fluid Flow
Authors: Liao Quan , Jen Tien-Chien
Published: August 2009

In this paper, a new pressure boundary treatment of lattice Boltzmann method (LBM) for fully developed pressure-driven periodic incompressible fluid flow is proposed. The pressure gradient, instead of equivalent body force, has been applied to determine the particle distribution function on the periodic traverse sections for the fully developed pressure-driven periodic flow. Numerical simulations, including 2D pressure-driven Poiseuille flow and fluid flow passing square obstacles, are carried out using this new boundary treatment. Simulation results show that the proposed approach not only overcomes the nonphysical inlet and outlet flow disturbances (which the LBM simulation always suffers from using the existing pressure boundary methods), but also preserves the system periodicity and generates consistent pressure distribution with macroscopic periodic boundary conditions for the pressure-driven incompressible fluid flow.
Developing X-Ray Particle Tracking Velocimetry for Applications in Fluidized Beds
Authors: Drake Joshua B. , Franka Nathan P. , Heindel Theodore J.
Published: August 2009

Fluidized beds utilize a gas stream to fluidize solid particles and are used in the process industries because they provide a low pressure drop, uniform temperature distribution, and high heat transfer rates. Knowledge of fluidized bed hydrodynamics is necessary in the design and scale up of such devices. However, fluidized bed hydrodynamics are difficult to visualize and quantify because the systems are opaque and intrusive probes do not provide satisfactory measurements. This paper describes the development of X-ray particle tracking velocimetry (XPTV) to study fluidized bed hydrodynamics. XPTV utilizes X-rays to track specially designed tracer particles in a fluidized bed to noninvasively determine particle velocities. Stereoscopic X-ray imaging is used to locate the 3D position of the tracer particle as a function of time within a fluidized bed, from which particle velocity can be determined. An example of particle tracking will be shown and the automation of this process will be described.
Atomization Characteristics, Global Emissions, and Temperature in Biofuel and Petroleum Fuel Spray Flames
Authors: Erazo Jaime A. , Parthasarathy R. N. , Gollahalli S. R.
Published: August 2009

Spray flame characteristics of canola methyl ester biofuel (CME) and petroleum fuel (No. 2D) are described. An enclosed spray flame in a heated co-flow air environment at ambient pressure was studied. A single nozzle, swirl-type, air-blast atomizer with a nozzle diameter of 300 microns was used to create the spray. The spray droplet size and velocity distributions were measured using a two-component phase Doppler particle analyzer. In-flame temperature profiles were measured using a type-R thermocouple. Global emission indices of NO and CO were derived from concentration measurements in the combustion products. The overall equivalence ratio was kept at 0.75 to simulate lean burning conditions. The changes in atomization air flow rate produced similar changes in atomization characteristics of both fuels. Emission indices of NO and CO for petroleum fuel were higher than those of the CME fuel. In-flame temperature levels were lower for the CME fuel than for the petroleum fuel at corresponding flame locations.
Generalized Model and Computational Algorithm for Modeling Passive Driveline Systems of AWD Automobiles
Authors: Shyrokau B. N. , Happawana G. S. , Vantsevich V. V.
Published: August 2009

The stability of motion and handling, mobility and fuel consumption of an all-wheel drive automobile depend on how the engine power is distributed among the front and rear axles and then between the left and right wheels of each axle. This power distribution is dependent on the properties of the driveline system and its power-dividing units (PDU) located between the drive axles and between the wheels of each drive axle. This paper presents a generalized driveline model and a computer algorithm. This model provides a way to model the power distribution among the four drive wheels of the automobile when using any of the existent passive power dividing units: open differentials, locked units, limited slip differentials with different locker properties and other mechanisms. The computer computational algorithm allows transferring each PDU from one state to another as a function of i) changes in the driving conditions, ii) the properties of the power-dividing unit, iii) variations in the mass and geometry parameters of the vehicle, and iv) its other systems (tires, suspension, transmission and engine). Using this generalized model and the computational algorithm in a MATLAB/Simulink environment, a program package is developed to embed into a computer model (user interested in investigating the effect of various driveline types on the dynamics of an all-wheel drive automobile). The paper presents examples of utilization of the above program package in investigating the features of curvilinear motion of an all-wheel drive automobile.
Mechanical Model and Control Strategy of a MEMS Inertial Gyroscope
Authors: Braghin Francesco , Leo Elisabetta , Resta Ferruccio
Published: August 2009

When designing a MEMS device, both the mechanics and the control logic have to be taken into account due to their strict interaction. The considered MEMS gyroscope is made of vibrating masses suspended through micro-beams with respect to the substrate. To increase the sensitivity of the MEMS gyro (i.e. the displacement of the suspended masses), it has been decided to work at low pressure values (26Pa). At first, the mechanical modelling of the device was carried out, paying special attention to the air damping at low pressure values. Then, the electronics used for the control of the device was integrated into the model thus obtaining a complete description of the sensor allowing to optimize design parameters. In order to validate the developed model, the MEMS sensor was produced and tested.
Transient Performance of a Cross Flow Heat Exchanger Using Finite Difference Analysis
Authors: Syed Fatir Hussain , Idem Stephen
Published: August 2009

Transient analysis of a cross flow heat exchanger subjected to a step increase in temperature of the minimum capacity rate fluid was considered. Predictions obtained using an implicit central finite difference method were presented. The influence of varying grid sizes and time steps sizes on these approaches was addressed. A parametric study was conducted by varying the dimensionless parameters governing the transient response of heat exchanger over a representative range of values.
Positioning and Tracking Control of an Amphibious Single Wheel Robot
Authors: Marzban Mostapha , Alizadeh Dina
Published: August 2009

Amphibious single wheel robot consists of a sharp-edged wheel actuated by a spinning flywheel for steering and a drive motor for propulsion. The spinning flywheel acts as a gyroscope to stabilize the robot and also can be tilted to achieve steering. In this paper, the kinematics of a single wheel robot in water, Gyrover, is analyzed and then a simple mechanism for driving it is proposed. In previous studies, Lagrange approach is used for hydrodynamic modeling of the robot. A nonlinear position controller is designed to bring the robot to any desired position. Based on the designed controller, a tracking controller is augmented to the robot. For simplicity the added mass effect has been neglected in hydrodynamic analysis. Since the robot under consideration is compact and slow enough, this assumption is not far from reality.
Nonlinear Distributed Modeling, Control, and Simulation of Rotating Stall and Surge in Transonic Compressors
Authors: Chi John N.
Published: August 2009

Aerodynamic instabilities that will limit the operating range, performance, and reliability of gas turbine engines include rotating stall and surge. These aerodynamic instabilities occur in the compressor at low flow rates. Enabling technologies that have been used to demonstrate the stabilization of compression systems and operating range extension by means of active feedback control include the manipulation of compressor flow field with inlet guide vanes, bleed valves, and air injection. A potential application of the performance improvement associated with active feedback control is to reduce the weight of an aircraft engine. The number of compressor stages required to achieve the same overall pressure rise can be reduced by using active feedback control to extend the operating range of a compressor with steep speed-lines. And since the compressor makes up a large percent of the weight of an aircraft engine, reducing the number of compressor stages will reduce the engine weight thus increasing its thrust to weight ratio. This paper presents a full state nonlinear distributed model of rotating stall and surge with an air injection actuation system, a nonlinear controller design, and a closed loop simulation architecture that can be used for evaluating different control algorithms. The full state nonlinear distributed model was validated with stall inception data from a transonic compressor, and a sliding mode nonlinear controller was designed using the validated nonlinear distributed model. The closed loop simulation setup was then used to compare the performance of existing baseline linear controllers with the nonlinear controller model presented in this paper. The simulation results showed that more operation range extension can be obtained with robustness to compressor disturbances by using single-sided sliding mode control law.
Advanced Heat Recovery Technology Improves Efficiency and Reduces Emissions
Authors: van der Linden Septimus , Romero Mario
Published: August 2009

An advanced patented process [1] for generating power from waste heat sources can be put to use in Industrial operations where much of the heat is wasted and going up the stack. This waste heat can be efficiently recovered to generate electrical power. Benefits include: use of waste industrial process heat as a fuel source that, in most cases, has represented nothing more than wasted thermal pollution for decades, stable and predictable generation capability on a 24 × 7 basis. This means that as an efficiency improvement resource, unlike wind and solar, the facility continues to generate clean reliable power. One of the many advantages of generating power from waste heat is the advantage for distributed generation; by producing power closer to its ultimate use, it thereby reduces transmission line congestion and losses, in addition, distributed generation eliminates the 4% to 8% power losses due to transmission and distribution associated with central generation. Beneficial applications of heat recovery power generation can be found in numerous industries (e.g. steel, glass, cement, lime, pulp and paper, refining, electric utilities and petrochemicals), Power Generation (CHP, MSW, biomass, biofuel, traditional fuels, Gasifiers, diesel engines) and Natural Gas (pipeline compression stations, processing plants). This presentation will cover the WOW Energy technology Organic Rankine Cascading Closed Loop Cycle — CCLC, as well as provide case studies in power generation using Internal Combustion engines and Gas Turbines on pipelines, where 20% to 40% respectively additional electricity power is recovered. This is achieved without using additional fuel, and therefore improving the fuel use efficiency and resulting lower carbon footprint. The economic analysis and capital recovery payback period based on varying Utility rates will be explained as well as the potential Tax credits, Emission credits and other incentives that are often available. Further developments and Pilot plant results on fossil fired plant flue gas emissions reductions will be reported to illustrate the full potential of the WOW Energy CCLC system focusing on increasing efficiency and reducing emissions.
Effect of Processing Methodology on Microstructure and Mechanical Properties of Sn-3.5Ag Solder
Authors: Babaghorbani P. , Gupta M.
Published: August 2009

The manufacturing techniques of powder metallurgy and casting were used to synthesize a Sn-3.5Ag followed by hot extrusion. In the sintering step of powder metallurgy, two routes of conventional and microwave sintering were investigated. Physical, microstructural, thermomechanical and mechanical properties of the developed solders were examined. These studies revealed that the best combination of the properties is realized from the Sn-3.5Ag synthesized using powder metallurgy incorporating microwave sintering route. An attempt is made to correlate processing-microstructure-properties relationship for Sn-3.5Ag.
Single Crystal Quartz a Replacement for Diamond Optical Windows
Authors: Sheehan Jessica
Published: August 2009

Diamond windows are used extensively in the field of optics due to their high transmittance and durability. However, despite their ability to withstand high pressures, diamond windows are not scratch resistant and need to be replaced when the surface is damaged. Moreover, the high cost of diamond windows necessitates extra care to protect the windows and limits the practical size of the window or lens. Thus, alternatives to the highly expensive diamond windows are needed in the optical sciences. A study of single crystal quartz has been conducted to determine if it will make a suitable replacement material. Since the transmittance of single crystal quartz is well documented and desirable for this application, only strength and surface defect experiments were conducted. Trials were run to determine the modulus of rupture of single crystal quartz samples which were also examined with an interferometer and an atomic force microscope (AFM) to correlate the surface conditions with the modulus of rupture. The results showed that even relatively numerous and large defects on the surface did resulted in single crystal quartz holding to high pressures. In addition, the measured modulus of rupture far exceeded the expected values proving that the single crystal quartz is able to withstand the pressures of vacuum. Single crystal quartz is thus found to be a viable alternative to diamond optical windows.
Off-Lattice Monte Carlo Simulation of the Thermal Conductivity of Single-Walled Carbon Nanotube-Polymer Composites With Inter-Carbon Nanotube Contact
Authors: Duong Hai M. , Papavassiliou Dimitrios V. , Yamamoto Namiko , Wardle Brian L.
Published: August 2009

A computational model is developed to study the thermal conductivity of single-walled carbon nanotube (SWNT)–polymer composites. An off-lattice Monte Carlo simulation was used to model the effects of interfacial resistance at the SWNT-polymer interface and at the SWNT-SWNT contact on the heat flow for different orientations of SWNTs dispersed in the polymers. A primary focus is the non-isotropic heat conduction in aligned-SWNT polymeric composites that are of interest for various heat conduction applications such as microelectronic heat sinks, and also because this geometry constitutes a representative volume element (RVE) of CNT-reinforced polymer matrices in hybrid advanced composites under development. The simulation is an extension of a previous model for heat transfer in nanocomposites in that it now considers SWNT-SWNT contact. The simulation results of the developed model are compared with those of the previous model. The effects of SWNT orientation, SWNT-SWNT contact, weight fraction and thermal boundary resistance on the effective conductivity of composites are quantified. The present model is a useful tool for the prediction of the thermal conductivity within a wide range of volume fractions of the SWNTs, including the case when SWNTs are in contact with each other.