Mechanical Engineering Commons^™

Robust Procedures For Obtaining Assembly Contact State Extremal Configurations, Pan Feng, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

Two important components in the selection of an admittance that facilitates force-guided assembly are the identification of: 1) the set of feasible contact states, and 2) the set of configurations that span each contact state, i.e., the extremal configurations. We present a procedure to automatically generate both sets from CAD models of the assembly parts. In the procedure, all possible combinations of principle contacts are considered when generating hypothesized contact states. The feasibility of each is then evaluated in a genetic algorithm based optimization procedure. The maximum and minimum value of each of the 6 configuration variables spanning each contact …

Low Reynolds Number Flow Through Nozzle-Diffuser Elements In Valveless Micropumps, Vishal Singhal, Jayathi Y. Murthy, S V. Garimella

CTRC Research Publications

Flow characteristics of low Reynolds number laminar flow through gradually expanding conical and planar diffusers were investigated. Such diffusers are used in valveless micropumps to effect flow rectification and thus lead to pumping action in one preferential direction. Four different types of diffuser flows are considered: fully developed and thin inlet boundary layer flows through conical and planar diffusers. The results from the numerical analysis have been quantified in terms of pressure loss coefficient. The variation of pressure loss coefficient with diffuser angle is presented for Reynolds numbers of 200, 500 and 1000. The pressure loss coefficients have been used …

Noble Metal Nanostructures Synthesized Inside Mesoporous Nanotemplate Pores, J. Arbiol, E. Rossinyol, A. Cabot, F. Peiro, A. Cornet, J. R. Morante, Fanglin Chen, Meilin Liu

Faculty Publications

Noble metal impregnation has resulted in the inclusion of metal nanostructures within the SBA-15 mesoporous silica hexagonal pores (from nanoclusters to nanowires). A bright-field transmission electron microscopy three-dimensional reconstruction is proposed to analyze the localization of nanostructures within the pores of mesoporous nanotemplates. The method allows corroboration whether the nanostructures are synthesized inside the pores or they are synthesized alternatively on the nanotemplate aggregates exterior surface.

Gradient-Based Non-Linear Microstructure Design, Brent L. Adams, M. Lyon

Faculty Publications

The support of this research by the Army Research Office is gratefully acknowledged. M. Lyon is supported by a National Science Foundation Graduate Research Fellowship. Fourier analysis is implemented on the orientation distribution of a polycrystalline microstructure. The linearity and convexity of the Fourier space, with respect to orientation, allows one to consider all possible distributions by considering all linear combinations of single-grain orientations. The limits of the Fourier space are therefore defined by the solutions to a set of linear programming problems. A unique approach to the linear programming, similar to the Krylov subspace methods for obtaining solutions to …

A Vector Quantization Method For Nearest Neighbor Classifier Design, Chen-Wen Yen, Chieh-Neng Young, Mark L. Nagurka

Mechanical Engineering Faculty Research and Publications

This paper proposes a nearest neighbor classifier design method based on vector quantization (VQ). By investigating the error distribution pattern of the training set, the VQ technique is applied to generate prototypes incrementally until the desired classification result is reached. Experimental results demonstrate the effectiveness of the method.

Coupled Problem Of Thermoelasticity For Multilayered Spheres With Time-Dependent Boundary Conditions, Zong-Yi Lee

Journal of Marine Science and Technology–Taiwan

This paper deals with quasi-static coupled thermoelastic problems for multilayered spheres. Using the Laplace transform with respect to time, the general solutions of the governing equations are obtained in transform domain. The solution is obtained by using the matrix similarity transformation and inverse Laplace transform. We obtain solutions for the temperature and thermal deformation distributions for a transient state. It is demonstrated that the computational procedures established in this paper are capable of solving the generalized thermoelasticity problem of multilayered spheres.

Numerical Optimization Of Sound Absorption Systems With Constrained Single-Layer Absorber, Ying-Chun Chang, Long-Jyi Yeh, Min-Chie Chiu, Gaung-Jer Lai

Journal of Marine Science and Technology–Taiwan

The thickness and the attached area of the sound absorber are confined in the practical engineering design while the sound absorber is applied inside the machine room to eliminate the reverberant sound energy. The optimization of the shape of the absorber and the quantification of the exact area of the absorber (in order to meet the required value of sound pressure level (SPL) at the concerned receiving point) becomes essential. For purposes stated above, two powerful gradient techniques with a logical control algorithm are applied during the optimization of the sound absorption system. Both the optimization of shape and the …

Effects Of Viscous Shear Stresses On The Squeeze Films Of Porous Parallel Rectangular Plates, Jaw-Ren Lin, Long-Jin Liang, Rong-Fang Lu

Journal of Marine Science and Technology–Taiwan

Considering the effects of viscous shear stresses, a study of squeeze-film behavior between porous parallel plates with finite width is presented. Based upon the Brinkman model (BM), two general coupled Reynolds equations derived for curved surfaces [20] are applied to predict the two-dimensional squeeze-film pressure and thereafter the squeeze-film characteristics. The results show that the BM predicts quite different squeeze-film behaviors to those obtained by using the slip-flow model (SFM) and the Darcy model (DM). Comparing with the SFM, the viscous shear effects provide an increase in the load-carrying capacity and lengthen the response time of finite porous squeeze-film plates. …

The Effects Of Couple Stresses In The Squeeze Film Characteristics Between A Cylinder And A Plane Surface, Jaw-Ren Lin, Won-Hsion Liao, Chi-Ren Hung

Journal of Marine Science and Technology–Taiwan

On the basis of the Stokes micro-continuum theory, the effects of couple stresses resulting from the lubricant blended with various additives upon the squeeze film behavior between a long cylinder and a plane surface are analyzed. Compared to the conventional Newtonianlubricant case, the couple stress effects characterized by the couple stress parameter signify an improvement in the squeeze film characteristics. Increasing values of the couple stress parameter increases the hydrodynamic load-carrying capacity and provides a longer time to prevent cylinder-plane surface contact. The approaching time of the cylinder in reducing the film thickness h m * = 1 to h …

Gas-Diffusion Process In A Tubular Cathode Substrate Of A Sofc, Part Ii: Identification Of Gas-Diffusion Process Using Ac Impedance Method, Kevin Huang

Faculty Publications

The effects of cathodic dc bias, bulk p_O2, and effective O₂ -diffusivity on ac impedance spectra of Siemens Westinghouse Power Corporation’s cathode-supported solid oxide fuel cells were systematically studied over a temperature range of 800 to 1000°C. It was found that the activation process dominated the overall electrode kinetics at 800°C, by which the applied dc bias reduced the electrode resistance considerably. With increasing the temperature to above 900°C, the activation process became effectively activated, leading to a visible arc at the lowest frequency on the impedance spectrum, which is relevant to the pore gas-diffusion process. …

Gas-Diffusion Process In A Tubular Cathode Substrate Of An Sofc, Part I: Theoretical Analysis Of Gas-Diffusion Process Under Cylindrical Coordinate System, Kevin Huang

Faculty Publications

In this the first part of a two-part paper, the gas-diffusion process through a thick and porous tubular cathode substrate of a solid oxide fuel cell-(SOFC) was theoretically analyzed using classic Fick’s diffusion equation under the cylindrical coordinate system. The effects of current density, temperature, oxygen diffusivity or porosity, wall thickness, and bulk p_O2 on the concentration (or pore in this paper) polarization were calculated and are presented graphically. The results clearly show a greater impact on pore polarization by current density, oxygen diffusivity, wall thickness, and bulk p_O2, but not by temperature. In addition, …

Studies On Yba2nbo6 And Yba2cu3-Xnbxoy Buffer Layers, S. Sathiraju, R. Wheeler, Paul N. Barnes, T. L. Peterson, Iman Maartense, A. L. Campbell, N. A. Yust, T. J. Haugan, Q. Jia, Paul Arendt, Sharmila M. Mukhopadhyay, S. Vemulakonda

Mechanical and Materials Engineering Faculty Publications

No abstract provided.

2004 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the spring of 2004.

An Investigation Of Fuel Consumption During The Warm Up Cycle Of A Gasoline Engine Using 87 Octane Ethanol Blended And Unblended Fuel, Michael Aaron Scott

All-Inclusive List of Electronic Theses and Dissertations

This research investigated fuel consumption during the warm up cycle of a gasoline engine using 87-octane gasoline blended with 0%, 10%, and 20% ethanol. The purpose of this research was to determine ifthere is a significant statistical difference in fuel consumption among the ethanol-gasoline blends controlling for temperature. The experiment identified three properties of ethanol blending: (1) energy (fuel) potential, (2) determination of the speed (time intervals) of the energy consumption within the engine, and (3) indirect effects on coolant temperature. The researcher selected the two-way ANOVA (analysis of variance between variables), covariant, and post hoc to analyze the raw …

Fatigue Of Drill Pipes Used In Horizontal Directional Drilling, Feibai Ma

Doctoral Dissertations

Fatigue is the most common cause of mini-HDD drill rod failure. It can occur at stress levels far below the normal operating stress in most drill stem components. Fatigue failures occur because the drill rod, after it has been forced into a curved path, undergoes a cyclic bending stress oscillating from tension to compression in concert with the other stress components caused by torque, thrust, or pullback.

When a rod breaks underground, there is considerable extra cost caused by the delay in “fishing” out the broken rod as well as the cost of replacing the rod. On the other hand, …

Analysis Of Combustion Chamber Design Variables In Planetary Rotary Engine, Sathyanarayanan Arumugam

Masters Theses

This research entails examining the Hopkins Rotor Mechanism (HRM) for the perspective of commercial viability. Factors that were studied herein include basic operating characteristics, combustion effects, dimensional changes and behaviors unique to the HRM that may impose limits to commercial viability were also examined.

To compare specific characteristics of the HRM engine, in a comparable four-stroke mode, hypothetical 200, 400 and 600 cubic centimeter (cc) single cylinder reciprocating engines, each with compression ratio of 10, 15 and 20 were used as a basis for comparison. For similar outputs this resulted in the use of a 100, 200, 300 cc HRM …

Subcooled Pool Boiling Heat Transfer Using R113 On Flat Surface, Kamleshkumar J. Suthar

Masters Theses

Pool boiling experiment was conducted to investigate the effect of subcooling on boiling of R-113 using 25mm effective dia. flat surface copper heater. Pool boiling heat transfer measurements were taken for wide temperature range of 5 - 39^o C subcooling and investigated thoroughly. Variation in value of wall superheat of incipience boiling, from 27 to 34^o C and 7 to 11^o C temperature excursion observed. Noticeable effect of subcooling on boiling heat transfer is observed. Degree of subcooling was maintained constant by regulating pressure and keeping constant fluid temperature for each test run. Tests were conducted by …

Methodology To Predict The Instantaneous Friction Work In Non-Conventional Internal Combustion Engines, Ravishankar Thangavelu

Masters Theses

Non-Conventional Internal Combustion Engine (NCICE) may utilize a variety of contact surface shapes, where both sliding and rolling losses occur. This study develops techniques that allow the user to define the type of forces and the characteristics of the friction type to predict the instantaneous and over all friction work in a NCICE under user defined operating conditions. The characteristics include inertial effects, contour and surface effects, resulting contact surface changes and film thickness changes as a result of contact surface.

Laser Ignition Of Pulverized Coals, John C. Chen, Masayuki Taniguchi, Kiyoshi Narato, Kazuyuki Ito

Mechanical Engineering

We present a novel experiment to study the ignition of pulverized coal. A dilute stream of particles is dropped into a laminar, upward-flow wind tunnel with a quartz test section. The gas stream is not preheated. A single pulse from a Nd:YAG laser is focused through the tunnel and ignites the fuel. The transparent test section and cool walls allow for optical detection of the ignition process. In this article we describe the experiment and demonstrate its capabilities by observing the ignition behavior of spherical, amorphous-carbon particles and two coals: an anthracite are a high-volatile bituminous coal. The ignition behaviors …

Analysis Of Kancil's Car Knuckle Prototype, Tresna P. Soemardi, Aida Mahmudah

Makara Journal of Technology

Analysis of Kancil’s Knuckle Prototype. The objective of this work is to execute strength analysis of knuckle, which is made from FCD 50, by using static analysis on maximum loading. This maximum loading is obtained from front axle loading calculation on particular operating condition. That is, vehicle is braking while cornering in down hill. From previous vehicle loading calculation, we get a number of loading values on different speed and deceleration. At the end, we get a value of speed and deceleration that guarantee the vehicle safety if it is braking while cornering in down hill. As comparison, loading calculation …

Pid Fuzzy Logic Controller System For Dc Motor Speed Control, H. Samsul Bachri M.

Makara Journal of Technology

PID Fuzzy Logic Controller System for DC Motor Speed Control. A good controller system must have resilience to disturbance and must be able to response quickly and accurately. Problem usually appears when PID controller system was built sensitively hence the system’s respon to the disturbance will yield big overshot/undershot then the possibility of oscillation to be happened is excelsior. When the controller system was built insensitively, the overshot/undershot will be small but the recovery time will be longer. Hybrid controller system could overcome those problems by combining PID control system with fuzzy logic. The main control of this system is …

Numerical Study Of Combustion Of Hydrogen And Ethylene In A Two-Dimensional Dual-Mode Scramjet Combustor, Robert A. Carson

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis presents computational fluid dynamics results for two-dimensional flow geometries utilizing two fuels, hydrogen (H2) and ethylene (C2H4). Upstream interaction was evident with the use of both fuels due in part to recirculation in the combustor, the inlet pressures and the combustion process. Results were obtained for hydrogen using a reduced chemical kinetic model while results obtained for ethylene employed a reduced chemical kinetic model as well as an expanded chemical kinetic model.

Initially, an examination of grid composition was conducted in order to select the most numerically efficient and accurate grid for reacting flow in the current combustor …

Using Stiffeners For Improved Geometric Fidelity Of Flexible Elements, Ankit Kapoor

Masters Theses

Flexible hoses play an important role in safe operation of a transportation vehicle in automotive and aerospace field. Due to lack of accurate and efficient modeling techniques for such flexible elements with large deformation, most Computer Aided Engineering system do not address the problem in their solution methods.

In this thesis a method is presented to improve the geometric fidelity of flexible element models by using off-axis bi-linear stiffeners (spring) into a discrete linear beam model. Resulting deflection of a hose were compared with the digital scans of an actual deflection of the hose. Though the method is computationally expensive, …

Comparing Refractory Coatings On Shell Sand Utilizing Elevated Temperature And Collapsibility Testing, Suet Fong Cheah

Masters Theses

This research study examines the effects of refractory coatings on a shell sand using laboratory testing equipment as opposed to the more laborious and time consuming processes of molding, melting, filling, shakeout, and obtaining dimensions of actual castings. As of today, there have not been any such laboratory test methods. This research project focused on quantifying distortion, mass change, and impact strength found in refractory coated shell sand. The equipment used was the thermal distortion tester (TDT) and a modified impact tester. The thermal distortion curves (TDC), mass change, and impact strength are provided and compared for all systems studied. …

Quarternair Cugasete And Cuga0.5in 0.5te2 Thin Films Fabrication Using Flash Evaporation, A. Harsono Soepardjo

Makara Journal of Technology

Quarternair CuGaSeTe and CuGa0.5In 0.5Te2 Thin Films Fabrication Using Flash Evaporation. Quarternair materials CuGaSeTe and CuGa0.5In 0.5Te2 are the basic materials to solar cell fabrication. These materials have high absorption coefficients around 103 – 105 cm-1 and band gap energy in the range of 1-5 eV. In this research, the films were made by flash evaporation method using quarternair powder materials of CuGaSeTe and CuGa0.5In 0.5Te2 to adhere in a glass substrate. After the films were obtained, the properties of these films will be characterized optically and electrically. The lattice parameter of the films and the crystalline film structure were …

Graded Channel Mosfet Simulation With S-Pisces 2b, Hartono Siswono

Makara Journal of Technology

Graded Channel MOSFET simulation with S-Pisces 2B. Graded-Channel Metal-Oxide-Semiconductor Field-effect- Transistor or GCMOSFET is being discussed in this paper. GCMOSFET technology has been developed to meet the growing demand for low power and high performance application. In this paper, it will be shown that, compared to ungraded MOSFET, the GCMOSFET device offers the advantage of significantly higher drive current. The higher drive current is achieved because the effecctive channel length of GCMOSFET is shorter than the ungraded MOSFET’s. From the simulation result with S-PISCES 2B and MATLAB, it can been shown that the ID from GCMOSFET is higher than the …

Construction Of Depth-Structure Shelf-Edge Map For Case Study Of Kujung Formation, East Java Sea, Saifatur Rusli, Suparto Suparto

Makara Journal of Technology

Construction of Depth-Structure Shelf-edge Map for Case Study of Kujung Formation, East Java Sea. In general, reflection seismic method has capability to represent sub-surface in time domain. Seismic cross-section that depicts the formation of sub-surface usually use time domain in the format of TWT (Two Way Times). This due to in the process of seismic data acquisition, seismic wave propagates in down-going and up-going manner so that the obtained results from data processing are in the format of TWT seismic vs. shot points. This paper will describe the construction of depth-structure map for case study of Kujung Formation, East Java …

Critical Variables Of Solder Paste Stencil Printing For Micro-Bga And Fine-Pitch Qfp, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Stencil printing continues to be the dominant method of solder deposition in high-volume surface-mount assembly. Control of the amount of solder paste deposited is critical in the case of fine-pitch and ultrafine-pitch surface-mount assembly. The process is still not well understood as indicated by the fact that industry reports 52-71% surface-mount technology (SMT) defects are related to the solder paste stencil printing process. The purpose of this paper is to identify the critical variables that influence the volume, area, and height of solder paste deposited. An experiment was conducted to investigate the effects of relevant process parameters on the amount …

High Temperature Heat Exchanger Project: Quarterly Progress Report January 1, 2004 Through March 31, 2004, University Of Nevada, Las Vegas. Research Foundation, Robert F. D. Perret

Publications (NSTD)

Mutually satisfactory language has been developed to permit signing of a subcontract between the General Atomics Corporation and the UNLV Research Foundation. The contract is signed.

Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Third Quarterly Report, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for superconducting cavities. The need for very clean surfaces lead to the use of a buffered chemical polishing produce for surface cleaning to get good performance of the cavities. The third phase concludes the experimental a fluid flow study and optimization study. The first quarter and second quarter of phase three also begins the experimental set-up of secondary emission studies from niobium in superconducting mode. This …