Mechanical Engineering Commons^™

A Finite Difference Solution Of An Ideal, Normal, Impinging Jet, Luis A. Gast

Theses

The free boundary of a circular jet of an irrotational, inviscid, incompressible, fluid impinging normally to a flat surface from a height of 2 times the nozzle radius, was found by a finite difference method.

Starting with a graphical solution, approximate values of the potential were given to the nodes at the field.

Having the equipotential lines perpendicular to the axis of the jet, perpendicular to the impinging surface, and having defined the value of the potential at both the entrance and exit of the jet, a finite difference expression of the Laplace's equation was used in an iteration scheme …

Finite Element Analysis Of The Femoral Head, Ghandikota Ramamurthy

Theses

Femoral component loosening and Prosthetic stem fractures have renewed interest in conservative alternatives to conventional total hip replacements. One such alternative is the concept of surface replacement. The objective in this study is a finite element analysis of a femoral surface replacement cup with Particular attention given to the interfacial stresses. An axisymmetric model with a grid of two-dimensional isoparametric elements is generated. This study utilizes an adaptive model so as to include the effect of bone remodeling in response to stress. The stiffness is considered to be linearly proportional to the stress in the femoral head and neck. Isotropic …

One-Dimensional Compressible Flow Analysis : Isentropic And Normal Shock, Su-Bo Wong

Theses

A computer program to compute and analyse one-dimensional isentropic compressible flow through variable cross-sectional area with or without a normal shock is developed. The program is written in the "FORTRAN LANGUAGE".

In this work, the area change is the predominant cause of change of flow condition. One of the advantage of this program is set on general uses for isentropic flow. In common practice, the values of the isentropic flow property ratios were tabulated or graphically presented as function of the Mach number with a specified specific heat ratio, K (normally K=1.40 was presented). With todays technology, the most versatile …

Computer Simulation Of Cavity Filling During Injection Molding Process, Sumit Banerjee

Theses

A numerical technique is proposed for the simulation of cavity filling process during injection molding of glass-bead filled polypropylene. The mold cavity is of cylindrical shape. Marker And Cell (MAC) method is utilized for solving the transient flow phenomena, after a mathematical simulation of the flow model is carried out by using the relevant continuity and-momentum equations governing the system. The complexity of the equations involved, results in the simplifying assumption of incompressible and isothermal flow process. A computer program is written on the basis of finite-difference equations developed during the application of MAC method under the prevailing conditions.

The …

Nomographs And Tables For Simplified Thermal Analysis Of Power Piping, Dhanjibhai N. Patel

Theses

This Thesis develops Nomographs and Tables for simplified thermal analysis of " Power Piping." It gives the length of required Thermal Relieve Leg when a set of piping parameters such as, pipe size, pipe material, operating temperature and pipe length are given.

The Nomographs and Tables developed here can be used

1. to determine the primary piping layout, piping route, support location etc. before vigorous conputer analysis is performed.

2. to help the Field Engineer on the plant site to make " on the spot " decisions on pending piping route changes.

Two Nomographs are developed in this Thesis. One …

On The Analysis And Design Of Clamped Rectangular Plate With Partial Load, Yacin Saaid Jaboury

Theses

In this Thesis, maximum deflection and bending moments of a partially loaded clamped rectangular plate are studied. The loading is uniformly applied to a retangular area proportional to the shape.

Navier's Solutions on partially loaded simply supported rectangular plate is superimposed with edge moments to give the clamped boundry condition.

Solutions of maximum deflection and bending moments are derived in Double Series form. A Fortran program is employed in obtaining the numerical results. When the partially loaded area approaches zero it becomes a centrally loaded case; and when loading area to plate area ratio approaches unity it becomes a uniformly …

Numerical Solution Of Navier-Stokes Equation By Finite Element Method, Kuan-Tzong Lee

Theses

A finite element method for solving the entrance flow in a parallel-plate channal at low Reynolds number has been studied. Two methods of formulation for both incompressible viscous and inviscid fluid flows were developed. The first uses stream function and potential function as field variables while the second uses velocity and pressure. Both formulations presented here ultilized variational principle and weighted residual method. The numerical example was solved by constrained variational principle with penalty functions in conjunction with the Newton-Raphson method. A 9-node quadratic quadrilateral element was used in this example. Numerical results for entrance flow problem were obtained for …

Sound Attenuation With Respect To Traffic Noise, Manuel Vierdt

Theses

The purpose of this investigation was to examine which single—number transmission loss rating is best suited for windows to predict indoor noise levels due to intrusive traffic noise.

The realized transmission loss values were determined from simultaneously recorded indoor and outdoor noise levels at four different locations (offices), facing busy roadways.

The noise data were analyzed in terms of third octave band levels (equivalent sound level and percent exceeded noise level) with different weighting curves applied.

The overall noise reduction values were compared with ratings based on a reference contour (shell isolation rating (SIR), sound transmission class (STC) ).

Special …

Crimp-Type Electrical Connectors, Ted Lai-Che Kuo

Dissertations

Three types of surface conditions (plain surface, plain surface with oxidation inhibitor, and toothed surface) and four types of environmental gases (air, nitrogen, hydrogen, and oxygen) were used to study the performance of electrical connectors installed on aluminum conductors. All of the connectors were placed insealed vessels which allowed the desired type of gas to flow at a steady rate. The connectors were then current cycled.

For the connections prepared with plain surfaces, the connectors deteriorated equally fast in air, nitrogen and hydrogen. Only the connectorsexposed to oxygen showed a higher deterioration rate than the others.

Connections prepared withhaving plain …

Deposition Of Particles In Vertical Conduits Due To Electrostatic Charge, Diffusion, And Gravity, Melvin Wilbur Gelber

Dissertations

This investigation was made to determine the effect on the deposition of fine particles in a vertical channel and in a vertical tube due to the influences of electrostatic charge, diffusion, and gravity acting in the direction of flow. The flow considered was laminar, incompressible and steady.

The governing equations for the fluid phase were derived from the Navier-Stokes equation and the continuity equation while the equations for the particle phase were derived from Poisson's potential equation and the continuity equation. Since the governing equations are non-linear partial differential equations the solutions were developed using numerical methods.

The flow patterns …

Deposition Of Suspensions In A Vertical Converging Tube, Kam-Ho Chan

Theses

The deposition of suspensions in a vertical converging tube with significant gravity effects Was investigated theoretically with control volume - finite difference approach. The fluid was assumed to be incompressible and laminar. The particle density was assumed to be uniform at the inlet of the. tube. The velocity profiles for the fluid considered were (a) Uniform profile, (b) Parabolic profile. The angles of convergence studied were 0°, 5° and 7°. Effects of velocity ratio δ^*(=terminal velocity/mean flow velocity) on the rate of deposition were investigated for δ^*=0,1,10.

It was found that deposition increases with increasing angle …

Impingement Of An Axi-Symmetric Jet On A Flat Surface, Amir J. Daibes

Theses

An incompressible, inviscid irrotational flow model was used to represent the normal impingement of a circular axisymmetric jet upon a flat plate. An analytical investigation was conducted to determine the free surface of the jet and the solution of the potential flow problem was obtained using finite difference techniques for jet height-to-nozzle radius ratio of 2.4.

The velocity and pressure distributions at the plate surface and along the jet centerline were obtained.

The results from the finite difference solution are in close agreement with other most recent results from available experimental, and approximate solutions to the potential flow problem.

Inplane And Out Of Plane Buckling Of Thick Rings Subjected To Hydrostatic Pressure, Thomas Michael Juliano

Dissertations

The problem of inplane and out of plane buckling of a thick circular ring subjected to a hydrostatic pressure is analyzed from first principals. The equations of equilibrium from nonlinear elasticity theory are used to describe two adjacent equilibrium positions, i.e., an initial and final state. The initial position problem is assumed to be governed by linear theory. The resulting incremental value equations obtained by subtracting the two equilibrium states, are also linear in nature. These problems are reduced to a one dimensional ring theory problem by the method of power series expansion of the displacements in the radial and …

Axisymmetric Air Jet Impinging On A Convex Hemispherical Plate, David C. Chan

Theses

Experimental investigation was conducted on an axisymmetric, submerged air jet impinging normally on a smooth convex hemisphere. Three nozzle diameters of 0.5" (12.7mm), 0.375" (9.525mm) and 0.25" (6.35mm) were used and tests were run at Reynolds number range of 14,700 to 84,000.

The results obtained in the free jet and deflection zones were found to confirm the works of previous investigators. As for the fully developed wall jet region, the following points are noted:

1. The maximum wall-velocity decay was found to possess a slightly higher rate than that of either the flat plate or the concave hemisphere.

2. The mean velocity …

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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 …