Mechanical Engineering Commons^™

Power Filter Resonant Frequency Modulation Network, Don Cronin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A power filter resonant frequency modulation network for coupling between a load and a variable voltage direct current power source which is subjected to superposition of alternating current thereon at various frequencies and at various voltage levels, the filter including first and second series inductor arrangements in the positive and negative buses between the power supply and the load, with capacitive elements in parallel between the two buses. Each series inductor arrangement includes a first inductor in series with a frequency and voltage responsive inductive load device, which is a second inductor having a tertiary winding loaded with a coil …

University Of Missouri-Rolla Cloud Simulation Facility: Proto Ii Chamber, Daniel R. White, James L. Kassner, John C. Carstens, Donald E. Hagen, John L. Schmitt, Darryl J. Alofs, Alfred R. Hopkins, Max B. Trueblood, Max W. Alcorn, William L. Walker

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Graduate Center for Cloud Physics Research at UMR Has Developed a Cloud Simulation Facility to Study Phenomena Occurring in Terrestrial Clouds and Fogs. the Facility Consists of a Pair of Precision Cooled-Wall Expansion Chambers Along with Extensive Supporting Equipment. the Smaller of These Chambers, Described in This Article, is Fully Operational, and is Capable of Simulating a Broad Range of In-Cloud Thermodynamic Conditions. It is Currently Being Used to Study Water Drop Growth and Evaporation for Drops Nucleated (Activated) on Well-Characterized Aerosol Particles. Measurements Have Been Made Not Only for Continuous Expansions (Simulated Updraft) But Also for Cyclic Conditions, …

The Force On A Lattice Defect In An Elastic Body, R. C. Batra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

It is shown that the force on a lattice defect in an elastic body is, like the force on a disclination in a nematic liquid crystal, a real force which, for equilibrium, must be balanced by an external force applied to the closed surface enclosing the defect. © 1987 Martinus Nijhoff Publishers.

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 …

Effect Of Material Parameters On The Initiation And Growth Of Adiabatic Shear Bands, R. C. Batra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The thermomechanical problem involving simple shearing of a finite slab made of an isotropic and viscoplastic material is studied with the objective of finding the effect of the strain hardening parameter, strain-rate hardening parameters, thermal softening coefficient and thermal conductivity on the initiation and growth of adiabatic shear bands. The body is placed in a hard loading device, i.e., the velocity is prescribed at its top and bottom surfaces. A shear band is presumed to have formed if the addition of a perturbation in the temperature at the onset of plastic flow results in a localization of the shear strain. …

Elasto-Composition Waves In Inhomogeneous Solids, R. C. Batra, Manfred Wuttig

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

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 …

Closed-Loop Dynamic Response Of A Static Scherbius Drive., Aaron J. Miles, B. Lequesne

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Generalized root-loci techniques, for squirrel-cage motors have been extended to wound-rotor, slip-energy-recovery systems (static Scherbius drive). The influence of a feedback control loop on these root loci is considered. General conclusions on Scherbius drive dynamics, as well as supporting experimental results, are presented.

Plasma Polymerization Investigated By The Substrate Temperature Dependence., H. Yasuda, Cheng Wang

Chemistry Faculty Research & Creative Works

In the reported experiments, plasma polymerization of tetrafluoroethylene (TFE), perfluoro-2-butyl-tetrahydrofuran (PFBTHF), ethylene, and styrene were investigated in various combinations of monomer flow rates and discharge wattages for the substrate temperature range of minus 50 to 80 degree C. The polymer deposition rates can be generally expressed by k//o equals Ae** minus **b**t, where k//o is the specific deposition rate given by k//o equals (deposition rate)/(mass flow rate of monomer), A is the preexponential factor representing the extrapolated value of k//o at zero absolute temperature, and b is the temperature-dependence coefficient. It was found that the value of b is not …

Generalized Root-Loci Theory For The Static Scherbius Drive, B. Lequesne, Aaron J. Miles

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Generalized root-loci techniques, developed in the mid 70's for squirrel cage motors, have been extended in the static Scherbius configuration to wound rotor, slip energy, recovery systems. This arrangement is now applied to large power drives in the 0.5 to 50 MW range. In this paper, general results applicable to all machines are presented for the open-loop control scheme, but only the sub synchronous mode of operation in which a voltage source type inverter is used is addressed. Copyright © 1984 by The Institute of Electrical and Electronics Engineers, Inc.

Generalized Root-Loci Theory For The Static Scherbius Drive, B. Lequesne, Aaron J. Miles

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

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), …

Electronic Ballast Having Emitter Coupled Transistors And Bias Circuit Between Secondary Winding And The Emitters, Don Cronin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An electronic ballast for energizing fluorescent lamps comprising a converter including a rectifier and a filter for converting an alternating source voltage into a direct current voltage, a network including first and second switching transistors, a tank circuit having a primary winding of a transformer, a secondary winding of the transformer for providing feedback of a portion of the voltage developed across the tank circuits and a bias circuit coupled between the opposite ends of the secondary winding and the emitters of the transistor for alternatively applying bias to the transistors, the network serving to convert a direct current voltage …

Applications Of Finite And Wave Envelope Element Approximations To Acoustic Radiation From Turbofan Engine Inlets In Flight, A. V. Parrett

Doctoral Dissertations

"The problem of acoustic radiation from turbofan engine inlets in flow has not lent itself fully to analysis by numerical means because of the large domains and high frequencies involved. This project has extended the use of finite elements and wave envelope elements, elements which simulate decay and wavelike behaviour in their interpolation functions, from the no-flow case in which they have been proven, to cases incorporating mean flow. By employing an irrotational mean flow assumption, the acoustics problem has been posed in an axisymmetric formulation in terms of acoustic velocity potential, thus minimising computer solution storage requirements. The wave …

Saint-Venant's Principle In Linear Elasticity With Microstructure, R. C. Batra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Toupin's version of the Saint-Venant principle in linear elasticity is generalized to the case of linear elasticity with microstructure. That is, it is shown that, for a straight prismatic bar made of an isotropic linear elastic material with microstructure and loaded by a self-equilibrated force system at one end only, the strain energy stored in the portion of the bar which is beyond a distance s from the loaded end decreases exponentially with the distance s. © 1983 Martinus Nijhoff Publishers.

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 …

Linear Inversion Method To Obtain Aerosol Size Distributions From Measurements With A Differential Mobility Analyzer, Donald E. Hagen, Darryl J. Alofs

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Use of a Differential Mobility Analyzer to Perform Aerosol Size Spectrum Measurements Requires an Inversion Method to Go from the Measured Sensor Responses to the Desired Size Spectrum Information. Here We Present a Linear Inversion Method that Can Be Run on a Microcomputer or a Small Minicomputer. It Does Not Use Some of the Approximations Made in the Techniques Currently Available and Hence Gives Better Inversion Accuracy. the Method Shows Good Immunity to Both Random and Systematic Experimental Error. It is Applied to Numerous Test Case Aerosols. © 1983 Elsevier Science Publishing Co., Inc.

Inversion To Obtain Aerosol Size Distributions From Measurements With A Differential Mobility Analyzer, Darryl J. Alofs, P. Balakumar

Mechanical and Aerospace Engineering Faculty Research & Creative Works

To Measure Size Distributions of Sub micrometer Aerosols with an Electrical Differential Mobility Analyzer (DMA) Requires an Inversion Procedure. the Knutson (1976) and the Hoppel (1978) Inversion Procedures Were Numerically Investigated for the Case of Log-Normal Aerosol Size Distributions. It Was Found that the Hoppel Procedure Converges to the Same Result as that Given by the Knutson Procedure. the Computational Range for Geometric Mean Diameter (Χ_g) Was 0.025-0.25 Μm, and for Geometric Standard Deviation (Σ_g) Was 1.1-2.4. the Inversion Error Was Found to Be Greater Than 10% in Certain "Forbidden Zones" of Χ_g and Σ …

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.

High Pressure Liquid Jet Nozzle System For Enhanced Mining And Drilling, B. P. Selberg

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This invention is directed to a nozzle configuration capable of enhancing the cutting and drilling effects of high pressure liquid fluid jets. The jet system is particularly adapted to configurations of two or more liquid jets which are oriented to converge at a common point. The internal nozzle configuration produces controlled instability in the jet stream causing a more rapid breakup into droplets which can be combined to produce very fast moving jets and slow moving jets when collision between droplets occur. The velocity of the fast jets so formed may be several times greater than the original velocity of …

A Potential Problem With The Tsi Electrostatic Aerosol Classifier, Darryl J. Alofs, Max B. Trueblood

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Economic Comparison Of Flat Rate And Concentrating Solar Collectors For Absorption Air-Conditioning, E. A. Sauer, Harry J. Sauer Jr.

UMR-DNR Conference on Energy

No abstract provided.

Estimation Of Water And Energy Requirements For Ground Water Heat Pumps In The United States, Ronald H. Howell, Harry J. Sauer Jr.

UMR-DNR Conference on Energy

No abstract provided.

Feasibility Study For A Municipal Refuse To Energy Plant, Archie W. Culp Jr.

UMR-DNR Conference on Energy

No abstract provided.

Novel Demonstration Of Total Internal Reflection, Dwight C. Look

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

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 …

Atmospheric Measurements Of Ccn In The Supersaturation Range 0.013-0.681%., Darryl J. Alofs, T. H. Liu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Concentrations of Cloud Condensation Nuclei in the Atmosphere Were Measured at Rolla, Missouri, Near Ground Level. a Total of 432 Spectra Were Measured over a 10-Month Period. No Consistent Seasonal or Diurnal Pattern Was Observed. Possible Implications for Fogs and Stratus Clouds and for Nuclei Chemical Composition Are Discussed.-From Authorscloud Condensation Nuclei Rolla Missouri Fogs

Combined Heat And Lass Transfer In Mixed Confection Ower A Horizontal Flat Plate, T. S. Chen, F. A. Strobel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The combined effects of buoyancy forces from thermal and species diffusion on the heat and mass transfer characteristics are analyzed for laminar boundary layer flow over a horizontal flat plate. The analysis is restricted to processes with low concentration levels such that the interfacial velocities due to mass diffusion and the diffusion-thermo/thermo-diffusion effects can be neglected. Numerical results for friction factor, Nusselt number, and Sherwood number are presented for gases having a Prandtl number of 0.7, with Schmidt numbers ranging from 0.6 to 2.0. In general, it is found that, for the thermally assisting flow, the surface heat and mass …