Mechanical Engineering Commons^™

Adaptive Critic Based Neural Networks For Control, Victor Biega

Masters Theses

"Dynamic Programming is an exact method of determining optimal control for a discretized system. Unfortunately, for nonlinear systems the computations necessary with this method become prohibitive.

This project investigates the use of adaptive neural networks that utilize dynamic programming methodology to develop near optimal control laws. First, a one dimensional infinite horizon problem is examined. The first part of this thesis considers problems involving cost functions with final state constraints for one dimensional linear and nonlinear systems. It also investigates a two dimensional linear problem. In addition to these examples, an example of the corrective capabilities of critics is shown. …

An Empirical Investigation Of Quality And Productivity Management Practices In Manufacturing Firms, Kiran Vuppalapati

Masters Theses

A growing number of firms are implementing the concept of Just In Time (JlT) manufacturing and Total Quality Management (TQM). This research examines the impact of these management philosophies in manufacturing firms.

This research identifies a set of critical organizational variables necessary for a successful . implementation and the organizational problems faced during their implementation. The major object is to test the performance of firms implementing both JlT and TQM against firms implementing none of these philosophies. Results show that JIT-TQM firms are more customer focused and have better employee relations than traditional firms. This study also compares the performance …

An Experimental Study Into The Role Of Routing Flexibility In The Justification Of Advanced Manufacturing Systems, Sanjay Pathak

Masters Theses

Increased competition in manufacturing has focused attention on advanced technologies. These costly technologies lead to difficulty in purchase justification using traditional methods. New methods quantify attributes relating to the flexibility of advanced systems. One such attribute is routing flexibility.

This thesis presents results of experiments into evaluation of routing flexibility. The performance of conventional dedicated machinery when compared with that of machines having routing flexibility indicates an advantage of flexible machinery. The thesis indicates a procedure for evaluation of different flexibilities and their comparison with conventional machinery in reality.

An empirical formula is developed that helps in quantifying routing flexibility …

Primary Coolant Flow Characteristics As It Exits The Palisades Reactor, Gregory Alan Baustian

Masters Theses

During fuel cycles 9 and 10 at the Palisades Nuclear Power Plant, new phenomena have been observed using the resistance temperature devices installed in the reactor coolant piping. Oscillations in the temperature readings have been observed leading to the assumptions that there is temperature stratification of the coolant in the reactor hot-legs and that the coolant rotates as it leaves the reactor. In addition, oscillations in the bulk coolant flow within the two hot legs have been postulated. This report outlines work performed using computational fluid dynamics modelling which predict the observed and assumed flow characteristics of the Palisades reactor …

Analysis Of Sandwich Plates Subjected To Blast Loading, Vijay Prasad Bulla

Masters Theses

A dynamic analysis is presented for the bending response of square sandwich plates with isotropic core and facings under blast type pressure. The maximum central deflections of simply supported plates under static and dynamic loadings are compared for various thicknesses and elastic moduli. The deviation of the thick sandwich plate results from the pure-bending theory results is presented for various core properties. Small deflection dynamic iso-response plots are shown for different core rigidities. To study the limits of small deformation linearity for various sandwich plates, non-linear results for deformations under high pressure loads are compared with the linear results. The …

Rolling Friction Research Instrument, John P. Ward

Masters Theses

An instrument has been analyzed, designed and constructed that will accurately measure the rolling resistance of metallic spheres an plane surfaces subjected to normal loading which will produce contact stresses approaching material yield.

Nonlinear Dynamic Finite Element Simulation Of Hydroelastic Mounts For Light Weight Vehicles, Talla Jayapal Reddy

Masters Theses

Modern light weight vehicles generate large noise levels, that may need bulky classical rubber mounts to suppress. Hydroelastic mounts can significantly reduce the vibration level of current production automobiles without weight penalty. However, the highly nonlinear behavior of hydroelastic mounts has not been established yet and its use is, therefore, limited to trial and error design methods.

This study discusses the implementation of nonlinear finite element simulation of hydroelastic mounts using the ANSYS finite element code. Fluid elements are limited to linear analysis and therefore are incompatible with the nonlinear hyperelastic elements. A method is proposed to simulate the fluid …

Silicon Carbide/Electroless Nickel Composite Plating For Aluminum Substrates, Ben Charbit

Masters Theses

The effectiveness of producing a composite coating by suspending micron-sized particles in an electroless nickel bath while plating a 2024T4 aluminum alloy part was studied. The variation in the count of particles trapped in the nickel coating due to changes in the particle size, concentration of the particles in the bath, and the substrate surface texture was also studied. Particle sizes of 1 micron and 10 microns, concentrations of 15 gr/lt and 30 gr/lt, and polished and blasted textures were used. It was found that this technique is an effective way to produce composite coatings rendering a high number of …

Laser Doppler Velocimetry Research Of The Blowby Gas Characteristics In An Internal Combustion Engine, Mark Kevin Coffill

Masters Theses

The project was designed to measure a reciprocating engine fluid flow (blowby gases past the piston rings) using a laser doppler velocimeter (LDV). Blowby gases were obtained by introducing compressed air into an engine cylinder (piston held at TDC) to simulate engine combustion pressures. Beginning the proposed research included starting an LDV/reciprocating engine laboratory at Western Michigan University and determining the limits of the measurement devices (LDV system in particular).

The limitations which were found in the LDV system only allowed for limited results of in cylinder optical measurements. The results obtained were for cylinder pressures below 0.6 kPa gauge …

Computational Simulation Of Flow Through Elbows In The Approach Piping Systems To A Headbox, Kasinathan Ramanathan

Masters Theses

The successful operation of the wet end in a paper machine is highly dependent on the approach piping system. Sheet basis weight stability and ease of making wet end adjustments are greatly impaired by improperly designed approach piping systems. Most problems in headbox approach piping occur when the flow splits, combines, and passes through elbows.

Elbows create cross flows, flow separation, and eddies, and play an important role in the uniform and stable delivery of the pulp into the headbox. The effect due to an elbow lasts for a considerable distance downstream of the elbow and is severe when two …

The Indentation Of Foam Pattern Surfaces By Coordinate Measuring Machine Probes, Sanjay Nenawati

Masters Theses

When coordinate measuring machines are used to measure the complex shapes of foam patterns, the spherical probe tips indent into the soft surface of the pattern. Such indentation represents a measurement error since the indicated dimension will not be the same as the actual dimension. To determine the magnitude of error, the depth of probe tip indentation into PMMA and EPS foam surface (i.e., elastic indentation) was measured as a function of time, applied load, and foam density. The residual indentation after the removal of the load (i.e., plastic indentation) was also studied.

The depth of elastic indentation increased with …

Computer Aided Process Planning System For Generating Alternative Process Plans, Rao T. Gali

Masters Theses

Computer Aided Process Planning (CAPP) has a key role in Computer Integrated Manufacturing (CIM) as an interface between design and manufacturing. Current CAPP systems treat process planning as a static function, and always generate the same machine and process combinations. Thus, these CAPP systems are inadequate for advanced manufacturing facilities such as Flexible Manufacturing Systems (FMS). This thesis presents research conducted for the design and development of a CAPP system called Alternative Computer Aided Process Planning (A-CAPP) which generates alternative process plans by interacting with production planning and machine loading functions to satisfy system capacity constraints.

A-CAPP is a variant …

System Modeling And Vibration Reduction Of A Flexible Beam Under Rotary Motion, Jui-Hung Chien

Masters Theses

"The objective of this thesis work is to reduce the end-point vibration of a flexible beam using the feedback control of the partial state variables. The dynamic model is derived from the assumed-modes method. The new feature of this model is that it is applicable to control system analysis and synthesis. A practical example is presented to illustrate the use of control law to improve the transient response"--Abstract, page ii.

Theoretical Thermodynamic Properties Of Low Temperature Fluids, Zul Azhar Zahid Jamal

Masters Theses

The thermodynamic functions for low temperature fluids are computed using parametric integral equations and perturbation theory. Parametric integral equation N is applied to a low temperature Lennard-Jones gas. It is found that there is no significant improvement over the better known parametric integral equation C. The two parameter integral equation T is applied to a low temperature square-well potential and is found to be unsatisfactory at reduced temperatures of T*= 1.4 and 1.6, but quite accurate at T* = 2.2. The equation T results for T* = 2.2 are used as the reference system in perturbation theory computations. Tables of …

Fluidized-Bed Gasifier Engine System Using Rice Hulls, Luis Cruz Baja

Masters Theses

"The operation of a fluidized-bed gasifier using rice hulls and a spark-ignition, internal combustion (IC) engine on product gas at the optimum reactor conditions and on gasoline produced generator loads of 6.7 KWe and 10.5 KWe at average speeds of 1740 RPM and 1785 RPM and thermal efficiencies of 12.7% and 13.8%, respectively. The diesel engine operation on dual diesel fuel oil (DFO) product gas and 100% DFO generated 8.0 KWe and 8.3 KWe at 1416 RPM and 1552 RPM and thermal efficiencies of 10.2% and 20.2% respectively. The gasoline engine could be run on 100% product gas while the …

Commercial Design Of Four Indirect-Fired Fluidized Bed Gasifer Systems, Eoin Myles Clancy

Masters Theses

"This thesis deals with the design and cost analysis of four scaled up gasification plants. Reactor outputs range from 10 to 40 million Btu/hr (heating value of gas). Scale-up design parameters are based on data obtained from a 20 inch indirectly heated steam fluidized bed gasifier. This produces a medium Btu gas (450 Btu/ft³). The gas may be burnt on site or used as a chemical feedstock.

The plant designs consider reactor sizes, steam plant dimensions, specifications for feedhoppers, cyclones, conveying equipment, internal firetube heat exchangers, and drying plants.

The economic analysis deals with the cost of the …

A Thermal Contact Conductance Correlation For Mechanically Expanded Finned Tube Heat Exchangers, Mahmoud Ahmed Abu Ebid

Masters Theses

"Tests were conducted in dry vacuum environment, on eight mechanically expanded finned tube heat exchangers (with 3/8 inch outer diameter tubes) with different geometries including variation in fin thickness, fin collar length, and net interference. One of the eight heat exchangers was also tested under wet conditions. A mathematical model was used to calculate the thermal contact conductance from the experimental data. An error analysis was performed to estimate the range of error in determining the thermal contact conductance. A correlation of the dry contact conductance in terms of fin number (actual fin collar length in contact with the tubes), …

Investigation Of Important Surface Characteristics Of A Finned Tube Heat Exchanger, Bobby Dale Stafford

Masters Theses

"Surface characteristics of a finned tube heat exchanger were examined to help predict the contact geometry between metal surfaces. These characteristics were the surface roughness and waviness and the material hardness. A scanning electron microscope was used to observe the surface topography of the fins as well as examining the contact between the aluminum fin and the copper tube.

Comparisons of the surface roughness were then made between heat exchangers having different fin numbers (20, 14, and 6) with the result that as the fin number decreased, the roughness also decreased. For a given fin number, it was discovered that …

A Technique For Obtaining Very Efficient Dynamical Equations For On-Line Computation Of Joint Forces Of Robotic Mechanisms, Dennis A. Dohogne

Masters Theses

"In order to increase the operational speed and positional accuracy of robotic mechanisms, on-line force control has been proposed. Because of the complexity of exact dynamical formulations, real-time computation of joint forces may be too slow.

Since force control is accomplished with a dedicated computer, unique, dedicated sets of force equations are justified. An efficient force computation technique based on the algebraic expansion and recombination of exact dynamics formulations is presented. Developments of the robotics matrix notation and of a Lagrangian dynamics formulation are also presented. A generalized three link manipulator model is used to compare the computational complexities of …

A Single Cylinder Engine Study Of Lean Supercharged Operation For Spark Ignition Engines, Kenneth Robert Schmid

Masters Theses

"A comprehensive single cylinder engine test program to evaluate Lean Supercharged Operation (LSO) for spark ignition engines was conducted. The evaluation involved an experimental program studying the power, emissions, and efficiency of a single cylinder engine. The relationships between engine power, efficiency, and emissions and the engine operating variables such as absolute intake manifold pressure, Exhaust Gas Recirculation rates, and spark timing were studied"--Abstract, page ii.

A Model For Optimization Of The Archer's Compound Bow., Mark Aaron Kincy

Masters Theses

"The object of this work is to establish an analysis procedure to permit optimization of the design of ti1e compound bow. The distinguishing features of the compound bow are a system of cables and eccentric pulleys which change the leverage between the bow string and the bow limbs as the string is drawn. This approach concentrates on an accurate representation of the limb mechanics which will allow the design of eccentric wheels to improve the energy storage potential of the bow and thereby increases the velocity of an arrow cast by the bow.

The compound bow is a rather unique …

The Effect Of Air Turbulence On The Rate Of Frost Growth On A Horizontal Flat Plate, Dennis Wayne Schulte

Masters Theses

“One factor currently affecting the efficient performance of finned refrigeration coils is frosting. This investigation determined the effect of air turbulence intensity on the growth rate of frost on a chilled flat plate in an effort to reduce the frosting problem.

Air turbulence intensities ranging from 1 to 22 percent were used with an air velocity of 590 fpm, and an air condition of 45°F and 0.0051 lb/lb humidity ratio, for the six hour tests. Additional tests at 7-8 percent air turbulence intensity were made for other air and velocity conditions.

The results showed that the effect of air turbulence …

Development Of An Integrated Program Of Water Reuse In A Pulp And Paper Mill, Zafar M. Chaudhri

Masters Theses

No abstract provided.

Influence Of Turbidity On The Stratification Development Of A Deep Water Reservoir., David Allen Prouty

Masters Theses

"The influence of turbidity on the diurnal temperature distribution and thermocline development in a deep water impoundment which is exposed to heating and cooling loads by convection, evaporation, and radiation is examined analytically. The diurnal behavior of the solar load, directional and spectral, is used with an isotropic multiple scattering model to simulate the attenuation of solar flux by turbid water. The diurnal behavior of the ambient temperature, humidity and wind speed were mathematically modeled to simulate the local (Phelps Co.) spring time of the year. The combined conduction and radiation energy transfer through the water was treated as a …

Theoretical And Experimental Investigation Of A Viscous Ring Nutation Damper., Roy Alexander Campbell Iii

Masters Theses

"The dynamics of passive dampers applied to high s peed gyro systems is reviewed briefly and the partially filled viscous ring nutation damper is investigated. Particular attention is given to 1 the broken ring or nutation synchronous configuration where the fluid moves as a rigid slug and the damping is greatest. In this mode the damping is assumed to be viscous and expressions for a linear damping constant are presented. Data from an experimental, high-speed gyro is used to verify the theoretical analysis"-- Abstract, p. 1

The Design Of A Hydraulic Jet Coal Cutting Head., Rodney Steven Eck

Masters Theses

"The use of high-pressure water as a tool for cutting coal is discussed. A proposed longwall coal mining machine utilizing oscillating water jets to cut coal is presented. Apparatus for experimentation using high pressure water involving single and dual oscillating jets was designed, constructed, and tested. The design of the cutting head for the proposed mining machine is considered"-- Abstract, p. ii

Two Dimensional Radiant Interchange Between Two Isothermal Semi-Infinite Parallel Strips., Stanley Earl Mckinney

Masters Theses

"Four straight forward solution methods were used to determine the two-dimensional variation of the radiosity on two identical constant temperature, gray, semi-infinite parallel strips. Physical convergence parameters were developed for the one-dimensional case and extended to two dimensions. A study using these parameters was undertaken to identify the preferable method. The solutions obtained with this "best method" agree well with the one-dimensional solutions. The error is estimated to be less than one percent" -- Abstract, p. ii

A Study Of Some Heuristic Models For Predicting The Reflection From Spherical Surfaces., Bruce Wayne Rau

Masters Theses

"Four heuristic models' available for predicting the behavior or radiation Non regularly reflected from spherical surfaces have been studied. The four models include: the classical Lambert, the s-factor as deduced by Look, the Lommel-Seeliger, and the Euler's approach. Because each of these analyses was deduced for flat plate geometry, it was first necessary to integrate these flat plate expressions over the surface of a sphere to develop appropriate expressions for the power rejected from the surface of a sphere based upon e ach of the above theories. As an integral part of this investigation, various basic quantities were listed (i. …

Data Acquisition And Analysis System For Computer Modal Analysis Of Automotive Exhaust Emissions., Edward Leroy Mabie Jr.

Masters Theses

"A data acquisition and reduction method for modal analysis of undiluted automotive exhaust emissions is presented. 'The procedure on which this method is based ·wa.s developed and presented in a. paper by Donald L. Stivender, in 1971, entitled, "Development of a Fuel-Based Emission Measurement Procedure." This method is presented as a. viable a.1ternative to the diluted constant volume sample by bag collection technique specified in the federal test procedure for emissions from light duty vehicles.

The instrumentation used for the acquisition of data was the type normally used for automotive emission studies. The four instruments used for exhaust gas analysis …

The Control Of Noise In Urban Areas., Edwin Eugene Frye Jr.

Masters Theses

"Noise has recently been labeled the 'fourth pollutant' and defined by some as the 'unwanted sound' that pervades our work environments and the privacy of our homes. This concern for noise and its effects has resulted from our nation's increasing population density, the increasing use of mechanized conveniences, the influx and growing use of mass transportation systems, and the public's awareness that noise not only 'annoys' and can increase everyday tensions and anxieties, but at certain levels can cause permanent hearing loss.

In order to curb the 'noise problem' legislators and municipal representatives began applying legal controls to noisy activities …