Mechanical Engineering Commons^™

A Three-Dimensional Kinematic Model Of The Human Knee, Wayne Ke-Wung Li

Theses

This thesis describes two kinematic models of human knee which may be used to study the motion of the knee and the forces in the ligaments of the knee. In one model, the ligaments are simulated by rigid links connected to links representing the articulating bones at the centroids of the areas of insertion of the ligaments. The condylar higher pair connections are simulated by equivalent linkages connected by resolutes. In an advanced model, the rigid ligament links are replaced by springs.

The IMP procedure, a powerful kinematic linkage analysis method, is employed to study the motion and forces in …

Interaction Between Structures And Fluids, Rahim Falsafi-Haghighi

Dissertations

A finite element model for the study of solid-fluid interaction, with applications in flow-induced vibration analysis of reactor vessel and heat exchanger internals, is presented. The model is based on the discretization of the solid equation of motion and the fluid continuity and momentum equations and employs the solid displacements together with the fluid pressure and velocity components as the nodal degrees of freedom. This permits a realistic and accurate implementation of boundary conditions, in contrast with methods using solid displacements and fluid pressure as the only field variables. The numerical solution of the resulting matrix equation, involving non-symetric matrices, …

Dynamics Of Submerged Cylindrical Shells With Eccentric Stiffening, Kerry Kier-Ten Chu

Dissertations

A theoretical analysis is presented for treating the free vibrations of submerged, ring stiffened cylindrical shells with simply supported ends. The effects of the eccentric stiffeners are averaged over the thin-walled isotropic cylindrical shell. The energy method is utilized and the frequency equation is derived by Hamilton's Principle. All three degrees of freedom are considered. Numerical results are presented for frequencies and mode separation for several cases of interest. Comparisons with previous theoretical and experimental results indicate good agreement. The cylindrical wave approximation and the plane wave approximation for the field equation were investigated. Their applicability was evaluated and the …

Deposition Of Suspensions In Laminar Flow In The Entrance Region Of Channels With Diffusive, Electrostatic And Gravitational Effects, Thomas Anthony Korjack

Dissertations

This investigation entailed the consideration of the deposition of suspensions in laminar flow in the entrance region of a parallel-plate channel, and both converging and diverging channels, under the combined influences of diffusive, electrostatic and gravitational effects. The fluid phase was assumed to be incompressible, steady and laminar; the particle phase was assumed to be steady, laminar, dilute, and with negligible lift force.

The complete solution of the problem involved solving the boundary layer equations for the completely viscous fluid phase, and the particulate momentum, continuity and potential equations for the particle phase. Since the resulting equations are non-linear partial …

Axisymmetric Air Jet Impinging On A Hemispherical Concave Plate, Stefan Jachna

Dissertations

This experimental study was conducted on an axisymmetric air jet impinging normally on a smooth, hemispherical, concave plate. The jet Reynolds numbers, based on bulk nozzle velocity and nozzle exit air properties, were between 14,000 and 75,000.

The impingement plate used in this work was a hemispherical surface with the radius of 94 mm.

Calibrated Pitot tubes and a micromanometer were used for pressure and velocity measurements. The Pitot tubes were mounted on precision positioning mechanisms permitting the accurate traversing of any direction in space. The test air flow rate was measured with calibrated rotometers.

The following results of this …

A Fast Boundary Tracking Alogorithm For Constrained Nonlinear Mathematical Programming Problems, Jacob Yaghoub Moradi

Dissertations

A fast search algorithm for the solution of nonlinear mathematical programming optimization problems is presented in this thesis. A gradient search procedure is combined with a "Boundary Tracking"(BT) method using the feasible direction finding method of Zoutendijk for generating a feasible starting direction along the feasible-infeasible boundary.

The algorithm is applied to the minimum weight design of submersible, circular, cylindrical shells reinforced by equally spaced "T" type frames. This problem had produced algorithm failure in two earlier studies and was only recently solved by the Direct Search-Feasible Direction Algorithm (DSFD) which was shown by recent comparison studies to be among …

Dynamic Analysis Of Structures With Solid-Fluid Interaction, Rennee Ramona Pedrido

Dissertations

Interaction between solid and fluid has been recognized to be an important factor in the areas of aeroelasticity, hydroelasticity, and the study of flow-induced vibration in nuclear reactor components. This study develops a finite element model for interaction between an elastic solid and a fluid medium. Plane triangular finite elements have been used separately for fluid, solid, and solid-fluid continua and the equivalent mass, damping, and stiffness matrices and interaction load arrays for all elements are derived and assembled into global matrices. The global matrix differential equation of motion developed is solved in time to obtain the pressure and velocity …

Thermal Stratification And Circulation Of Water Bodies Subjected To Thermal Discharge, Mohammad A. Borhani

Dissertations

A three-dimensional analytical model for large water bodies is presented. Time histories and spatial distribution of pressure, velocity and temperature in water bodies, subjected to thermal discharge, are determined employing a digital computer. The dynamic response is obtained for a rectangular water body by applying a finite difference method to the mass, momentum and energy balance equations. These partial differential equations are algebraically manipulated to obtain; 1) three parabolic differential equations integrated temporally to find the horizontal velocity components and temperature; 2) one algebraic integral equation to get the vertical velocity component; 3) one elliptic differential equation integrated spatially to …

Deposition Of Suspensions In Laminar Flow In The Entrance Region Ofa Channel And In A Diffuser, Shawki Mahmoud Eldighidy

Dissertations

In this investigation, the deposition of suspensions in laminar flow in the entrance region of a channel and a diffuser was considered.

The particulate phase was considered to he under the action of the electric field force clue to electrostatic charges. In addition, a lift force acting on each particle at the wall arising from the fluid shear near the wall and an adhesive force between each particle and the wall due to the difference of the material properties for both particle and walls were considered as surface forces.

The suspension flow was assumed to be incompressible, laminar, dilute, and …

Design And Analysis Of An Instrument System For Rheological Testing Of Whole Blood Samples, Robert Rimvydas Sinusas

Dissertations

The dissertation covers the conceptual design of a rheometer for testing whole blood samples through to the clotting state. While the design aims at increased measurement accuracy, the design employs well known technologies and available components.

The main reason for preoccupation with blood testing is that recent investigations have indicated that physiological disorders can be correlated with rheological properties of blood. The pursuit of an improved means of correlation is initiated with a survey of the rheological properties of blood. The relevance of these blood properties is then discussed. From this discussion a broader blood model is developed as a …

Vibration And Buckling Of Elastic Plates With Shear And Rotatory Inertia, Bomi Batiwalla

Dissertations

The effects of shear, rotatory inertia and inplane forces on the transverse vibration of thin plates are studied. In addition, the effect of shear on the buckling of thin plates is examined. A general differential equation of motion is derived for an isotropic thin plate subjected to normal and inplane forces with the consideration of shear and rotatory inertia. The method of internal constraints and Hamilton's principle are utilized.

The resulting fourth order differential equation is solved for simply supported plates of various shapes by employing a finite difference technique. The shapes examined are a square, a circle, a circular …

The Creep And Stress Relaxation Behavior Of Silver Bearing Copper Wire, Alfred Fox

Theses

Creep and stress-relaxation experiments were performed on silverless and silver bearing copper in the temperature range 73F to 250F. The creep experiments were conducted at constant load and temperature, the stress-relaxation tests at constant total strain and temperature for a total time period of 1000 hours. The effect of silver addition of up to 0.2 percent w/o (60oz per ton) on the creep and stress-relaxation behavior of spectrographically pure copper (99.999+ Cu) as well as on that of tough pitch and oxygen free coppers of lesser purity was studied. Spectrographically pure copper was found to be much more susceptible to …

The Effect Of Variable Properties On The Laminar Flow Of Gases, Norman Shilling

Dissertations

The problem of heat transfer in laminar flow of a gas through a constant diameter cylindrical tube is treated. The gas is cooled by the tube walls held at constant temperature. Two tube inlet conditions are considered: (1) fully developed velocity and uniform temperature profiles (Graetz boundary condition) and (2) uniform velocity and temperature (UTV) profiles. Results of the theoretical and experimental phases of the work are presented.

The theoretical solution is based on the compressible boundary layer equations with varying transport and thermodynamic property terms retained. For the Graetz condition, an existing finite difference solution scheme is modified for …

A New Technique For Steady State And Transient Analyses Of Incompressible Flow Networks, George V. Catanzaro

Theses

A new technique for the calculation of the transient or the steady-state mass flow rate and pressure distribution in incompressible flow networks is presented. Employing the matrix method of network analysis, the nodal continuity and branch momentum equations are solved simultaneously to obtain explicit relations giving the unknown nodal pressures and branch mass flow rates. In this manner, the transient or the steady-state behavior of incompressible flow networks with arbitrary configuration having nodal sources and sinks as well as branch transducers can be determined. In contrast with the conventional steady-state network analysis methods, the new technique can be extended to …

Transverse Vibration Of A Class Of Orthotropic Plates, Nicholas J. De Capua

Dissertations

This study determines the eigenvalues, eigenvectors, and nodal patterns of a class of orthotropic plates whose geometry is governed by the equation

(x/a)^α + (y/b)^β = 1,

where the parameters a, b, a, and a permit the plate geometry to vary over a range which includes the rhombus, circle, ellipse, square, and rectangle.

Variable thickness, inplane forces, and mixed or discontinuous boundary conditions are also considered. The following assumptions have been employed:

i). plate is thin with respect to other dimensions,

ii). deflections are small,

iii). rotary inertia and shear are neglected.

The method of analysis employed is …

A Theoretical And Experimental Study Of The Mechanism Of Axoplasmic Convection In Nerve Fibers Driven By Peristaltic Surface Waves, Robert John Biondi

Dissertations

In the study of cell biology, investigators have found that substances which are produced within the cell nucleus are sometimes found throughout the cell at points distant from the site of production. In the case of nerve cells (neurons), this is particularly dramatic because of the unusual elongated geometry of these cells.

A neuron possesses a cylindrical tubular extension called an "axon" or "axis cylinder" which is characterized by a large length-to-diameter ratio (10³-10⁶). The existence of a continuous proximo-distal flow of axoplasm within these cylindrical axons has now been demonstrated by numerous investigators. In …

Theoretical And Experimental Evaluation Of Cardiac State Utilizing Indicator Dilution Methods For Nonuniform Ventricular Mixing, Stanley Myron Welland

Dissertations

This research is directed toward the development and application of a new approach to the evaluation of cardiac work to diagnose cardiac state. A procedure has been developed for calculating the work performed on the fluid by the left ventricle during the heartbeat. The procedure involves the continuous direct measurement of ventricular fluid mixture temperature during and following the controlled injection, through a catheter, of a known volume of cold saline into the left ventricle. The measured mixture temperatures are used to calculate continuous ventricular volumes during the systolic and diastolic functions of the heartbeat. Plotting measured ventricular pressure versus …

On The Classification Of The Solution Space Of Linear Anisotropic Elasticity, Richard Clement Carman

Dissertations

A method is developed within the framework of Synge's function-space interpretation of problems in linear elasticity which allows the consideration of solutions to problems for anisotropic media in terms of the solutions of a corresponding isotropic problem and corresponding simpler anisotropic problems. The isotropic solution and simpler anisotropic solutions establish points in each of the statically and kinematically admissible spaces for the anisotropic problem. The established points are used to define sets of vectors in the statically and kinematically admissible spaces. The linear independence of these vectors can then be determined by a pair of criteria developed in this work. …

Non-Linear Analysis Of Electrocardiogram Tracings In Detection Of Occult Coronary Artery Disease, Joseph Robert Levitt

Dissertations

The general problem of identifying significant characteristics of a system by analyzing the properties of a signal emitted by that system is common to many disciplines, biological as well as physical. In general, achievement of a satisfactory solution depends on the capability of assigning membership of candidate signals to one of a number of mutually exclusive categories:

In this study, a new technique of processing the standard electrocardiograms from human subjects has been developed. This technique employs a set of non-linear transformations which enable the assignment of electrocardiograms into one of two Mutually exclusive categories. The first category is that …

Extension And Application Of The Sedov-Berdichevskii Variational Principle, Francis X. Prendergast

Dissertations

The Sedov-Berdichevskii variational principle is extended, and this extended principle is employed in the construction of a shell theory.

The extension of the principle is accomplished by the use of Lagrangian multipliers, and a redefinition of terms in order to maintain the original generality of the principle. The Euler equations of the extended variational principle provide, in addition to those obtained in the original principle, elastic and plastic kinematic relations, and, elastic and plastic constitutive relations. Also, the Euler equations of the original principle are obtained in a physically more meaningful form. Examples are given which show how this principle …

Dynamic Stress Concentrations About An Epilliptical Discontinuity In An Elastic Solid, Kenneth Roy Schroll

Dissertations

The redistribution of dynamic stresses caused by the presence of an elliptical discontinuity in an infinite isotropic homogeneous elastic solid is examined. The solutions are obtained for the special cases of the rigid immovable inclusion and the vacuous cavity inclusion, and numerical results are presented.

The solutions to the wave equations in elliptical coordinates are expressed in series of the elliptical geometry eigenfunctions. Application of the boundary conditions, vanishing displacements for the rigid immovable inclusion and vanishing stresses for the cavity inclusion, yields in each case two infinite sets of linear algebraic equations for the expansion coefficients of the series …

The Computer Evaluation Of The Natural Frequencies Of Vibrating Circular Plates With Free, Fixed And Simply Supported Edges, Thomas Michael Juliano

Theses

The natural frequencies of the transverse vibration of a thin, isotropic, circular plate with free, clamped, and simply supported edge conditions were studied extensively. The frequency equation for each edge condition was derived from the classical partial differential equation of plate vibration. These equations, which are in terms of Bessel functions, were then solved numerically to find the natural frequencies. Since the accuracy of the Bessel function values is very important in evaluating these frequencies, a comprehensive digital computer program was devised to calculate these values to eleven digit accuracy. In this Bessel function program four different methods were required …

Experimental Investigation Of Submerged, Incompressible, Turbulent, Impinging Jets, David Tzeh-Hsian Lee

Theses

Measurements concerning various flow parameters of jets impinging on a smooth lucite plate and a heated metal plate have been carried out. In particular, it is shown that the potential core length of a jet is a function of the Reynolds number and of the jet diameter. It has also been demonstrated that impinging jets behave in many important respects like free jets, except in the immediate vicinity of the target plate.

The flow behavior in the wall jet zone was investigated experimentally, and a satisfactory agreement with the results of the previous investigators was found. The maximum velocity decay …

The Effect Of Internal Combustion Engine Operation Upon The Viscometric Properties Of Polymer Thickened Multi-Viscosity Crankcase Oils, William Charles Philcox

Theses

The effects of engine mileage upon the viscometric properties of seven different brands of multi-viscosity engine oils were examined by subjecting each brand of oil to an average of 1500 miles of service in the crankcases of different passenger cars.

Oil samples were taken every 500 miles after the oil was put in the crankcase. The control oil sample was taken from a can of oil at the time the oil was put in the engine.

The viscosity indices and kinematic viscosities at 100° F and 210° F were calculated for each sample of oil. The percent change in viscosity …

The Effects Of Air-Water Two Phase Flow On The Performance Of A Centrifugal Pump, Karnig Ekizian

Theses

This study investigates the performance of a 1-inch long 4-vane open impeller centrifugal pump under two phase flow conditions. The paddle wheel pump, as branded by its manufacturer the Worthington Corporation, had a specific speed of 3400 (based on gallons per minute, feet of water and revolutions per minute) corresponding to a 7-inch impeller diameter. A 1/8-inch perforated steel pipe carried the compressed air to within four inches of the impeller eye where the air was injected into the water stream (See figures 18 and 20).

The three variable inputs were, water flow rate, pump speed and air flow rate. …

Heat Transfer Between A Turbulent Round Jet And A Segmented Flat Plate Perpendicular To It, John Edward Chamberlain

Theses

Heat transfer between a room temperature, turbulent round jet and a segmented flat plate perpendicular to it has been investigated.

The heat transfer surface consisted of invar rings insulated from each other with silicone rubber. The source of heat was steam at atmospheric pressure condensing on the back of the heat transfer surface.

Since data were taken over a wide range of vertical distances between the nozzle and the flat surface both the potential cone and the fully developed regions of the jet were observed interacting with the heated plate.

It was determined that two modes of heat transfer occur; …

Behavior Change Through Training, Robert Walter Messerschmidt

Theses

This thesis represents an investigation of attitude and behavior change as a result of human relations training, The elements of heredity and environment are proffered as a basis for attitude and behavior formation. It is denoted that these elements are also instrumental in subsequent development of adult behavior.

As noted in the literature, the term "individual differences" embodies the effect of virtually unique heredity and environmental conditions to which each person is exposed. These differences are also partly determined by the growth in developmental trends, which varies from individual to individual and from time to time.

The existence of individual …

Cuprous Oxide Rectification, Philip G. Cobb

Theses

It has been shown that cuprous oxide, when formed from a copper surface by suitable heat treatment, has remarkable rectifying properties towards alternating voltages applied through the oxide and copper. The purpose of our work was to investigate, the effect fully from all angles possible, and especially from those considerations affecting the constancy and permanence in the electric circuit.

The work ranged from furnace operation to tests of completed units, and further to the development of a theory explaining as completely as possible this rectifying property.

It soon became apparent, that here was ideal thesis material, and so, with proper …