Engineering Commons^™

Kinematic Synthesis Of Deployable-Foldable Truss Structures Using Graph Theory, Dirk B. Warnaar

Mechanical & Aerospace Engineering Theses & Dissertations

A graph theoretic approach is applied to the conceptual design of deployable truss structures. The characteristics that relate to the inter-connectivity of the elements of a deployable truss structure can be captured in a schematic representation, called a graph. A procedure is presented that enables the exhaustive generation of these graphs for structures of any given number of nodes and links and which are foldable onto a plane or onto a line.

A special type of truss structures, called truss modules, is presented. Graphs of this class of structures form a subset of the graphs of truss structures. Two procedures …

Prediction And Control Of Asymmetric Vortical Flows Around Slender Bodies Using Navier-Stokes Equations, Tin-Chee Wong

Mechanical & Aerospace Engineering Theses & Dissertations

Steady and unsteady vortex-dominated flows around slender bodies at high angles of attack are solved using the unsteady, compressible Navier-Stokes equations. An implicit upwind, finite-volume scheme is used for the numerical computations.

For supersonic flows past pointed bodies, the locally-conical flow assumption has been used. Asymmetric flows past five-degree semiapex cones using the thin-layer Navier-Stokes equations at different angles of attack, freestream Mach numbers, Reynolds numbers, grid fineness, computational domain size, sources of disturbances and cross-section shapes have been studied. The onset of flow asymmetry occurs when the relative incidence of pointed forebodies exceeds certain critical values. At these critical …

Maximum Likelihood Estimation For Distributed Parameter Models Of Large Beam-Like Structures, Ji Yao Shen

Mechanical & Aerospace Engineering Theses & Dissertations

Proposed large space structures have many characteristics that give an advantage to modeling their structural dynamics by a set of partial differential equations (PDE's). By far, the most effort put forth in studying system identification and control to date has been based on finite element models. Despite its acceptability, such lumped parameter models have inevitable deficiencies primarily because of their complexity. Both approaches are complementary and each should be used where it is most effective. But the fact is that the distributed parameter approach has not been developed to the level of maturity as for the lumped parameter approach.

Motivated …

Simulation Of 3-D Viscous Flow Around A Nozzle-Afterbody At High Speeds, Wendy B. Hoffman

Mechanical & Aerospace Engineering Theses & Dissertations

Turbulent shear flows at supersonic and hypersonic speeds around a nozzle-afterbody are numerically simulated and investigated. The specific application is for the flow around the nozzle-afterbody of a generic hypersonic vehicle. Accurate simulation of viscous, separating flows is not an easy task, and it is complicated by turbulence modeling concerns. A main objective of this study is to numerically simulate the afterbody flowfield while addressing the turbulence modeling problem. The viscous flow considered i~ this study is characterized by three-dimensional corner flows, shock boundary layer interactions, plume flow, shear layers, and cross-flow separations. Accurate simulation of this flow requires solution …

A Simulation Analysis Of The Usaf Commissary Customer Service Environment In Support Of Afcoms Store-Level Staff Sizing, Bruce H. Fritz Ii

Theses and Dissertations

This Thesis sought to determine the probable impact of the proposed Air Force Commissary Service (AFCOMS) manpower standard for customer service (manpower standard) upon commissary operating environments and to investigate the sensitivity of performance parameters within the customer service system. Specific problems addressed were: (1) Comparison of the cashier manpower requirements calculated by the proposed AFCOMS manpower standard to those determined by a simulation model under similar conditions; (2) Calculation of the expected mean and maximum waiting times in the commissary given the proposed standard; and (3) Determination of the sensitivity of customer waiting time performance measures to variations in …

Investigation Of Effects Of Nose Bluntness And Angle Of Attack On Slender Bodies In Viscous Hypersonic Flows, Ashwini Kumar Sehgal

Mechanical & Aerospace Engineering Theses & Dissertations

Hypersonic flows over cones and straight biconic configurations are calculated for a wide range of free stream conditions in which the gas behind the shock is treated as perfect. Effect of angle of attack and nose bluntness on these slender bodies in air is investigated extensively. The numerical procedures are based on the solution of complete Navier-Stokes equations at the nose section and parabolized Navier Stokes equations further downstream. The flow field variables and surface quantities show significant differences when the angle of attack and nose bluntness are varied. The complete flow field is thoroughly analyzed with respect to velocity, …

Measurement Of Voltage And Current In Electric Power Systems, Michael Davis

Opportunities for Undergraduate Research Experience Program (OURE)

A. B. Chance Company of Centralia, Missouri requested a study of the latest state-of-the- art technology to measure voltage and current on a normal distribution power line. (4kV - 35kV)

The particular device that A. B. Chance needs must be relatively inexpensive, $200.00 per measurement, reliable, and capable of being manufactured by them.

Four types of power line measurement techniques were investigated; electrooptics/magnetooptics, present day measurement devices, the Raychem Line Monitor, and remote voltage and current sensing (RVCS).

The remote voltage and current sensing idea is the basis of the following report.

Modeling For Supersonic Missile Wing-Body Interference Lift, Howard S. H. Ho

Opportunities for Undergraduate Research Experience Program (OURE)

During the initial phase of a missile design, a quick and simple way of estimating wing-body interference is essential. A simple panel model based on the cross flow over a cylinder is developed to estimate the effect of the body on the wing lift This model produces quick and reasonably accurate results, while little user expertise is needed. This model determines K_WB (upwash interference factor) and K_Φ (sideslip interference factor), and is applicable to infinitely thin delta and clipped delta fins on missiles in supersonic flight. The effects of the fin semivertex angle, span, taper ratio, free stream …

Model Calculational Approach To The Conformation Of Adsorbed Polypeptide Fragments, Timothy J. Mckeon

Opportunities for Undergraduate Research Experience Program (OURE)

The focus of the paper is to examine possible conformational changes of peptides when placed in the presence of a poly-synthetic material. A major concern in the pharmaceutical industry is the loss of potency of polypeptide drug products during processing, packaging and storage. An example of this is polymer syringes being used in place of glass ones. The effect is that some protien-derived products experience structural changes due to contact with the polymer. This is otherwise known as surface denaturation. In order to understand the energetics of interfacial polypeptide systems, a calculational approach was used via the program Alchemy. The …

Development Of A Large Commercial Transport Model For A Real-Time Digital Flight Simulator, John Francis Winkler

Opportunities for Undergraduate Research Experience Program (OURE)

In order to test the adaptability of the University of Missouri-Rolla's flight simulator to different types of aircraft, a basic mathematical model of a large commercial transport aircraft is developed. The original aircraft model is based on the Cessna 210, and in order to accommodate the drastic differences between the Cessna 210 and the Boeing 747, many changes are made to the simulation code. The aircraft geometric data, stability and control derivatives, and weights data are altered to match those of the 747. Changes are made within the various subroutines to include thrust reversal, spoilers, and a variable incidence horizontal …

Control And Data Reduction Software For Umr Neutron Spectrometer, Matthew K. Mclaughlin

Opportunities for Undergraduate Research Experience Program (OURE)

A double-scatter time-of flight neutron spectrometer has been obtained by the Nuclear Engineering department of the University of Missouri-Rolla (UMR). As this device was an experimental prototype which was never brought to full operation, the chance to work with two of the original builders of the spectrometer at EG&G Idaho was an excellent opportunity. Part of the work being done with the detector is the development of a PC-based software package for machine control, data acquisition, and data reduction. It is this part of the project which has been supported by UMR’s Opportunities for Undergraduate Research Experience (OURE) program.

The Electrochemical Characterization Of Ferrocene As A Guest Molecule In The Presence Of Ss-Cydodextrin, Anne T. Roberson

Opportunities for Undergraduate Research Experience Program (OURE)

This experiment involves the development of electrochemical experimental methods for the determination of the oxidation/reduction potentials of a guest ferrocene complex (C₁₀H₁₀Fe) hosted by ß-cyclodextrin. The project was conducted so that the specific interaction of two molecules forming a unique inclusion compound can be used as a model for rapid analysis of other small molecules. In principle, the study is based on the expected equilibrium interaction of the iron compound with ß-cyclodextrin resulting in a complexed and an uncomplexed species equilibrium. The project's experimental objective is to determine if the redox potentials of both complexed and …

Some Stability And Control Aspects Of A Variable Pivot Wing Configuration, Paul Vitt

Opportunities for Undergraduate Research Experience Program (OURE)

In supersonic flight, there is a large positive shift in the static margin, which causes extreme positive shifts in longitudinal stability, and is an undesirable characteristic. This paper investigates some of the stability and control aspects of an alternative configuration, that of a variable pivot wing aircraft -- an aircraft with two sets of wings, one set sweeps forward, the other set sweeps rearward. By prescribing a sweep schedule, it is desired to minimize the static margin shift with Mach number. The effects of the two lift elements -- that of mechanical shift of the center of pressure forward with …

Development Of A Learjet Model 24d For The Umr Flight Simulator, Richard Stigall

Opportunities for Undergraduate Research Experience Program (OURE)

A flight simulator was recently developed at the University of Missouri-Rolla for a single engine aircraft. The need soon arose for a higher performance aircraft. After exploring several possibilities, a Learjet Model 24D was chosen to include the high performance aircraft.

The purpose of this project was to develop a model for the Learjet 24D. This was accomplished by examining the computer code previously written and determining the changes needed. The code for the simulation is located in various subroutines. Each subroutine was analyzed to determine if changes needed to be made. When a modification was needed, appropriate methods were …

Computer Visualization Of Irrotational Flow Over Bluff And Streamlined Bodies, Nora Okong' O

Opportunities for Undergraduate Research Experience Program (OURE)

Computer programs were developed to visualize irrotational flow over bluff bodies (circular cylinders and half-bodies) and streamlined bodies (elliptical cylinders and airfoils). The method of superposition of flows was used, with stream functions or complex velocity potentials for fundamental flows being added to obtain the flows over the bodies. For the flow over the circular cylinders, half-bodies and elliptical cylinders, the stream function was calculated directly. The flow over the airfoil was obtained by Joukowski mapping of the imaginary part of the complex velocity potential for flow over a circular cylinder.

The programs developed will be valuable learning tools for …

Two-Phase Flow Measurement, Glenn Brenneke

Opportunities for Undergraduate Research Experience Program (OURE)

Liquid fuel engines have many applications in today's world. Diesel, spark-ignition, and gas turbine engines, and furnaces are just a few of the many applications of liquid fuel sprays. With the rising cost of fuel and need for energy conservation it is imperative that more efficient engines be developed. Analyzing liquid fuel spray characteristics non-intrusively could unlock the door to powerful highly efficient engines in the future.

The vaporization of fuel is mandatory in liquid fuel combustion. Vaporization and the fuel to air ratio are important characteristics of the spark-ignition engine. Compression ignition is controlled by the parameters of the …

Identity Authentication Based On Keystroke Latencies Using Neural Networks, Angela Lammers, Sharon Langenfeld

Opportunities for Undergraduate Research Experience Program (OURE)

Most computer security systems verify the identity of a user through objects in the user's possession such as keys or magnetic cards, or through knowledge the user has, such as a password or PIN number. There are, however, two other methods of user verification, which have as yet received little or no attention. There has been some work done on the third method, recognition of physiological patterns (such as finger prints, retinal patterns, or voice patterns), but this work has been limited and requires expensive hardware to implement. The final method of user verification is through actions such as signature …

Establishment Of A Phase/Doppler Particle Analyzer For Two-Phase Flow Experiments, J. L. Burget

Opportunities for Undergraduate Research Experience Program (OURE)

The accurate measurement of liquid spray drop size and velocity is important in a variety of applications. These applications include agricultural sprays, furnaces, spark ignition and compression ignition engines, gas turbines, and a variety of industrial processes. Because of the need to improve combustion efficiency and minimize soot and other harmful emissions, one of the most active areas of research is fuel spray combustion. Quantitative measurements of the vapor phase in fuel sprays is vital to the understanding of spray dynamics and the operation of combustion devices.

There are various measurement techniques available to measure vapor phase characteristics in a …

The Edge Strength Of Annealed And Heat-Strengthened Glass, Gregory P. Sallee

Opportunities for Undergraduate Research Experience Program (OURE)

Sadly, up until now, very little research has been conducted in the field of glass window strength. The purpose of this research, therefore, is to explore the topic of glass window strength such that we might offer some conclusive evidence as to the probable in-situ performance of structural windows. Our intention is to examine the specific phenomenon of thermally- induced stress and its effect on glass strength. J. G. Croll explains the existence of this well-documented problem. "Whenever a structure is subjected to a varying temperature distribution, or where it is prevented from free expansion, stresses will be induced that …

Vertical And Angular Motion Of A Wing Model In Steady Flow: A Physical And Numerical Experimental Study, Andrew P. Johnston

Opportunities for Undergraduate Research Experience Program (OURE)

The dynamic response of a rigid wing in steady flow mounted on translational and rotational elastic supports is investigated. This study presents both a numerical and a physical experimental arrangement that can be employed to investigate the effect of a wide range of parameters on the response of the wing subjected to steady flow. An interactive computer program, which utilizes the fourth order Runge-Kutta integration scheme to solve the governing differential equations, is discussed. The program output allows for quick visualization of the change in response due to parameter changes. An experimental arrangement that utilizes the new 18" x 18" …

Simulation Modeling In Manufacturing Cell Design, Debra A. Hunke

Opportunities for Undergraduate Research Experience Program (OURE)

The interwoven phases of the manufacturing process in Computer Integrated Manufacturing (CIM) require a carefully designed facility. Simulation modeling can be combined with other techniques to provide a rigorous methodology for CIM system design. This paper describes CIM, simulation ana their relationship. A case study demonstrates the described methodology in the design of a flexible manufacturing cell.

Implementation Of The Articulated Total Body (Atb) Model On An Apollo Workstation, M. F. Laudon

Opportunities for Undergraduate Research Experience Program (OURE)

The Articulated Total Body Model (ATB) is used for predicting gross segmented body response in various dynamic environments. The ATB computer program, originally written by the Department of Transportation as a Crash Victim Simulation (CVS) program, was later modified by the Calspan Corporation and More recently by the Armstrong Aerospace Medical Research Laboratory (AAMRL) to allow for aerodynamic force applications, harness belt capabilities and hyper-ellipsoidal graphical display of the modeled segments. The ATB model has been successfully used to investigate gross human body responses to bodies placed in such complex dynamic environments as high-speed aircraft ejection. This ATB model is …

The Detection And Quantification Of Atrophic Rhinitis Using Ditigal Image Processing Techniques, Timothy Mussman

Opportunities for Undergraduate Research Experience Program (OURE)

This project focuses its attention on the detection and quantification of Atrophic Rhinitis (A.R.), a disease prevalent in pigs. A.R. causes some of the bony structure in a pig's snout to atrophy, which exposes the animal to other diseases that may effect its growth. It is studied by examining a cross section of the pig's snout. By comparing areas and perimeters of the nasal cavity to bony structures, or turbinates in the snout, one can determine the severity of the atrophy. Currently, the veterinarians diagnosis is based on a subjective analysis of the snout. The problem with this method is …

Measuring Hydrogen In Galvanized Steels, Timothy O'Hearn

Opportunities for Undergraduate Research Experience Program (OURE)

There has been much investigation in the past concerning ways to eliminate the embrittling effects of hydrogen in galvanized steel components. Such galvanized parts are used extensively in the automotive industry. One solution that is commonly used is to anneal the galvanized parts at approximately 200 degrees Celsius for 4 to 24 hours. This annealing process does restore the ductility. However, very few if any experiments have been done to measure the amount of hydrogen released and the temperature dependence of the hydrogen release. This investigation is part of an on going effort to measure the hydrogen released from galvanized …

Border Detection Of Skin Tumor Images, Mike Tiehes

Opportunities for Undergraduate Research Experience Program (OURE)

Border detection of skin tumor images is part of a research project whose purpose is to identify key features in skin tumor images using machine vision techniques. The key features present in a skin tumor guide the dermatologist in making the proper diagnosis. A few examples of key features are crust, scale and ulcer.

Bundled Cable Parameters And Their Impact On Emi Measurement Repeatability, Deanna L. Weil

Opportunities for Undergraduate Research Experience Program (OURE)

This research project was 99% experimental, therefore, not many theoretical ideas will be presented. The main idea behind the project was centered around cable bundling. The effect of cable bundling using analytical measurements and data from a network analyzer was investigated.

A Computer Simulation Of The Umr Reactor, H. Allen Wilkins

Opportunities for Undergraduate Research Experience Program (OURE)

The Opportunities for Undergraduate Research project entitled, "A Computer Simulation of the UMR Reactor" had two goals. To produce a reactor simulation to be used in creating an artificial intelligence based reactor simulation for the UMR Nuclear Reactor and to produce a means of teaching students the fundamentals of reactor operations.

The primary purpose was to create a program which would simulate all the situations one would encounter in actual reactor operation. With the simulator the artificial intelligence system could be thoroughly tested before use with actual reactor data.

This same simulator would be used as a teaching aid for …

Monte Carlo Simulation Of Millimeter-Wave Gunn Effect Oscillators, Ramani Vaidyanathan

Electrical & Computer Engineering Theses & Dissertations

Monte Carlo simulations have been carried out to investigate the performance of microwave Gunn oscillators. Three separate aspects of the simulation problem have been comprehensively addressed in this work. First, the presence of an external circuit has been self-consistently incorporated into the calculations. The inclusion of the external circuit facilitates a study of the circuit controlled regime, and correctly models effects arising from the time dependent boundary conditions. Secondly, microscopic details of the electronic relaxation mechanisms which ultimately control the frequency response limits, have been taken into account through an iterative Monte Carlo-Poisson scheme. This procedure overcomes a potential shortcoming …

Q Improvement Of A 5.2 Ghz Te011 Cavity By Incorporating Y1Ba2Cu3O7-X, R. Joseph Leclear

Electrical & Computer Engineering Theses & Dissertations

Research is undertaken to apply high temperature superconducting material to improve the quality factor (Q) of a 5.2 GHz cylindrical resonant cavity. In particular, the approach is to electrophoretically deposit polycrystalline Y₁Ba₂Cu₃O_7-x (YBCO) on the conducting surface of the cavity cylinder. Spalling of the YBCO ceramic coating due to expansion and contraction of the cavity during sintering and testing is overcome by segmenting the cylinder. Results show that the Q of the cavity is increased over that of a copper cavity at temperatures below 60 K. At 20 K, improvement exceeds a factor …

Magnetic-Field Distributions In Zinc-Nickel Ferrite, T. A. Dooling, Desmond C. Cook

Physics Faculty Publications

The Mössbauer effect has been used to study the microscopic magnetic properties of the cubic microwave ferrite (Zn_0.41Ni_0.59)Fe₂O₄ at 300 K. The magnetically split spectrum is broad and unresolved due to the overlap of the hyperfine magnetic fields at the tetrahedral and octahedral sites. This is caused by a distribution of magnetic fields at each site. The distribution is especially large and asymmetric at the octahedral site and is due to the fact that the iron atoms at this site are influenced by the presence of both iron and zinc at the tetrahedral …