Mechanical Engineering Commons^™

Development Of A Computer Model To Track Water Droplet Trajectories As Related To Aircraft Icing, Satyen G. Harve

Theses

In order to be able to predict the local ice accretion rate, or the icing profile on any surface it is neccessary that a model be available, which helps in determining the local impingement values of water droplets on the object. Two models have been developed. One model determines the potential and the velocity field around any arbitrary object. The second model determines the trajectory of the water droplets in the presence of a potential field. The two models have been combined to form a general trajectory model capable of tracking water droplet trajectories around any arbitrary object. The object …

Enhancement Of The Integrated Mechanisms Program (Imp) By Addition Of Graphic Output, Anil Parsaram Hingorani

Theses

The Integrated Mechanisms Program (IMP) is enhanced to include the capability of graphic output of simple mechanisms. The subroutines available in the graphics package GP-10 are used. The output consists of a drawing of the mechanism at its initial position and for every position for which the analysis is done. In addition, a graph of velocity and/or acceleration against the angle of the driving link may be plotted. There are limitations. The output of the mechanism represents only prismatic joints by a different symbol. It is represented by a rectangle and the symbol of the fixed link. All the other …

Energy And Economic Analysis Of Alternate Total Energy Systems, Swaminathan Balakrishnan

Theses

The purpose of this study is to evaluate the Performance of Diesel engines, gas engines, and gas turbines when used in a Total Energy System. To begin with, the history of cogeneration was studied, current literature and texts reviewed and companies which deal with these engines or turbines were contacted. Electricity and gas tariffs were obtained from the P.S.E.&G. Co. It was decided to consider an apartment complex of approximately 200,000 ft² having peak heating and cooling loads of approximately 4.92 million Btu/hr and 2.93 million Btu/hr respectively for this analysis. The average electrical demand was 520 KW. Next …

Deposition Of Suspension In Inclined Channels Due To The Effects Of Inertia, Gravity And Image Force, I-Hsi Chu

Theses

This investigation was made to determine the effect on the deposition of particle in an inclined parallel-plate channel due to the influences of image charge, viscosity, inertia and gravity. The flow considered was lamina, imcompressible and steady. The flow patterns considered were uniform and fully developed with symmetry about the axis of the channel.

The governing equations derived for a particle were based on Newton's Second Law of motion. Since the resulting governing equations are linear second order differential equations, Runge-Kutta algorithm is used to solve the problem and graphical techniques is used to interpret the results of the numerical …

Computer Simulation For Studying The Performance Of Plasticating Extruders, K. S. Govindaraju

Theses

A Computer program for simulation of a single screw plasticating extruder is presented. The computer program simulates the performance of different size extruders with various screw geometries for plasticating and pumping different thermoplastic resins. The simulation yields valuable information on the performance of an extruder for a variety of operating conditions. The simulation program provides a means of separating the effect of one variable at a time on the overall performance of the extruders.

On Analysis Of Small Bore Piping Vibrations, Nitinkumar Shroff

Theses

This thesis investigates the natural frequency and vibration induced stress of small bore power plant piping. Straight piping and piping with concentrated load, such as a valve, located anywhere along the span are studied. Four different boundary conditions of fixed-free, simple-fixed, fixed-fixed and simple-simple are investigated, as any single span piping may be approximated by one of these boundary conditions.

The results otained [sic] for frequency and stress coefficients in the case of straight piping are plotted. Plots of frequency factor and stress ratio for the piping with concentrated load are also presented.

The results obtained for the natural frequencies …

Intelligent Computer Decision Systems, Robert J. Heath

Theses

This paper demonstrates that the concepts developed through Artificial Intelligence research are applicable to computerized information systems; and that a system of expert problem solvers and natural language interfaces exhibiting characteristics of "intelligent behavior" offer several advantages over present-day, conventional database management designs. Development of the conclusion was accomplished after an analysis and assimilation of the current literature in the field of Artificial Intelligence and participation in university symposia concerning its application to the business environment. It is concluded that incorporating the notions of learning and creativity, common sense(heuristics), and self-awareness, intelligent computer decision systems will provide managers with : …

Modification Of A Heat Transfer Program (Stan5) To Account For Surface Roughness And Its Application To Aerodynamic Icing, Parthasarathy R. Iyengar

Theses

In order to be able to predict the local ice accretion rate or the icing profile on an airfoil, it is necessary that a suitable heat transfer coefficient model be availabIe. A computer program has been developed which is capable of predicting the local heat transfer coefficient for a typical two dimensional icing surface. Because of the charecteristics of an icing surface, an existing computer program (STAN5) has been modified to include the effects of the following surface roughness surface curvature and boundary layer transition.

The computer program for the heat transfer coefficient has then been used with an existing …

Computer Analysis Of The Stefan Problem In Cryosurgery, Dong Hyuk Kim

Theses

Numerical solutions for determining the freezing front location vs time relation in cryosurgery are obtained by utilizing the heat transfer computer program TRUMP, which employs the explicit finite difference algorithm. The probe geometries of rectangular, cylindrical, and spherical shape with one dimensional heat flow are selected for study. Internal heat generation is considered in cylindrical and sphe¬rical probe geometries, and the difference between the solutions with and without heat generation is discussed. To verify the correctness of the TRUMP solution, comparisons are made in the freezing distance vs time relation with the Neumann's solution and the implicit enthalpy method for …

Plate Buckling Under Biaxial Patch Loading, Herli Surjanhata

Theses

This thesis is concerned with the buckling of rectangular plate-shaped elements under biaxial compressive loading with patch loading along one pair of opposite edges. The loading along the other edges is continuous but the discontinuous loading covers different patches along opposite edges. All the applied loads are uniformly distributed. The critical buckling load of this type of plate element is an important factor in the optimal design of many types of thin-walled structures. Frequently the nature of the problem prohibits an exact or even a general form of solution, thus dictating a numerical approach.

The problem has been attacked to …

Flow In A Channel With An Abrupt Change In Area : Finite Element Method, Ching-Fu Yu

Theses

Steady flow with an incompressible non-viscous fluid in a two-dimensional channel with an abrupt change in the width of its flow passage has been studied with a finite element method and a complex potential method.

The flow problem was solved with the use of an existing finite element program, FLOW2, in terms of the velocity potential and the stream function. The general procedure of solving problem by finite element method and the user's guide of FLOW2 program are presented in this thesis.

A computer program, EXACT, has been written for the exact solution based on the complex potential method to …

A Model Of Heat Transfer By Conduction And Radiation In Fluidized Bed, Kouadio Kouame

Theses

A model of heat transfer by conduction and radiation in fluidized beds operating in the bubbling regime is proposed. The analysis of the combined conduction and radiation is one dimensional and is based on the emulsion packet model. The problem is formulated in terms of a non-linear partial differential equation which is transformed into an ordinary differential equation by using the similarity transformation. The packet emulsion phase is assumed to be a semi-infinite medium which absorbs, emits and scatters thermal radiation. Moreover, the packet emulsion phase is considered to be under optically thick condition. Radiative transfer during bubble contact is …

Techniques For Measuring Critical Loads In The Presence Of Non-Negligible Higher Mode Imperfections, Rajendra W. Ranadive

Theses

This thesis is concerned with the Southwell Plot method for measuring the critical load of thin-walled structural members whose postbuckling behavior is stable-symmetric.

In this method measurements are taken of the structure's central lateral deflection versus membrane compressive load P. Southwell's hypothesis is that (on a graph of δ/P vs. δ the reciprocal of the slope gives the critical load. He suggests that this is valid because the effect of the fundamental imperfection predominates as the load approaches the critical load+

The writer has examined Southwell's hypothesis in the presence of non-negligible (in fact dominant) higher mode imperfections. The writer …

Coupled Flexural And Torsional Vibrations Of Beams, Sang Hwan Kim

Theses

This thesis deals with the vibration of a beam whose flexural and centroidal axis are not coincident. The elementary bending- twisting theory is employed to derive the equations of motion, in which the effects of rotary inertia are added to the bending displacements and the effects of warping are added to the twist. Bending translation is restricted to one direction so that one bending equation is used instead of two. The equations of motion are solved by using the boundary value problem. The exact natural frequencies are found from the frequency equation , which is obtained from the condition that …

Deposition Of Particles In Cylindrical Chamber Due To The Effect Of Image, Inertia, Viscous And Gravity Forces, Mehul J. Shah

Theses

This study investigated the behaviour of charged particles in cylindrical chambers under the influence of image, inertia, viscous and gravitational forces. The flow was considered to be laminar, steady state and incompressible. The velocity profiles considered were uniform and parabolic with symmetry about the axis of the cylinder.

The governing equations derived were based on Newton's second law of motion. The equations for the case neglecting gravity are linear second order equations and the Runge-Kutta method was used to find a numerical solution. The data hence obtained is fitted to equations using curve fitting method. These equations and graphical techniques …

Finite Element Modeling Of A Femoral Stem In A Total Hip Prosthesis, Robert C. Cohen

Theses

A three-dimensional model was produced to study of effects of stress on a femoral stem in a total hip prosthesis. Using the ANSYS General Purpose Finite Element Computer Program, a reproduction of the system was constructed for the loads acting on the hip joint at intervals of a walking cycle. With isotropic properties for cortical bone, cancellous bone, cement, and selected alloys, the model was generated using three-dimensional, isoparametric, eight-node, solid elements (STIF45). The model consists of over 700 nodes and 442 elements. This model can be used to produce computer calculated stress data, if disc storage space allows.

An Experimental Evaluation Of The Effect Of Evaporative Cooling Of Condenser Air On The Performance Of An Air Conditioning System, Arun Ananth Pai

Theses

The effect of evaporative cooling of condenser air on the performance, specifically cooling capacity and the coefficient of performance of an air conditioning system was determined. The dry bulb temperature of the entering air for an air cod-ed condenser was brought down to near saturated wet bulb temperature by spraying water into the incoming air and the effect on the cooling capacity of the evaporator was observed. Experimental curves were developed, which displayed the time/temperature difference history for both the condenser and the evaporator; consideration being given for both with aid without evaporative cooling of the condenser air.

Successive families …

The Application Of The Finite Element Method To Plate Stress Analysis, Yao-Zong Jen

Theses

The finite element formulation of plane elasticity and plate bending is presented and is employed in the development of the formulation of element stiffness equations and structural stiffness equations. The basic relations used to derive the finite element equations for a solid continuum are also presented. The programming organization is summarized.

The computer program cited from TAYLOR has been used to solve the deep beam problem with triangular and rectangular elements and the SAP IV program has been used to solve the plate bending problems with quadrilateral elements. Problems solved are: (1) stress distribution at the midspan of a simply …

Analysis Of Deflection Temperature Under Load, Anand M. Jagani

Theses

Deflection Temperature Under Load (DTUL) is an experimental value commonly used by designers to characterize a plastic in a high temperature environment. This value is currently measured by a standard test procedure specified by the ASTM D-648. A theoretical analysis of this test was made and computer programs were developed to calculate the Deflection Temperaure of Plastics Under Load based upon temperature dependent flexural modulus data and temperature dependent thermal properties of the plastics of interest. The results obtained from the theoretical analysis agree closely with the experimental values found in the literature for two resins. An analysis of the …

High Speed Puncture Impact Studies Of Structural Foam Plaques, Shashi B. Kumar

Theses

The constant velocity high speed impact study was conducted on different thermoplastic and thermoset structural foam plaques to study their impact behavior. Plaques of Noryl, Polycarbonate, Polystyrene and Polyurethane were carefully chosen to represent a true sample of the manufactured product. Test plaques were marked such that specimens could be tested for variation in location, thickness of the plaque and variation between plaques. High speed puncture impact experiment was conducted on each specimen and the results were analysed.

The test results showed that the impact performance varied significantly over the plaque. Noryl and Polycarbonate did not exhibit any correlation for …

An Interactive Procedure For Numerical Design Optimization, Jaehwan Lee

Theses

An interactive version of the numerical design optimization method of Pappas for the solution of nonlinear optimization problems is presented in this thesis, A designer intervention strategy is employed herein for interactive optimization to allow the designer to control and manage the optimization process. This procedure embodied in the interactive CADOP6 program is tested on the ten bench mark problems of Eason and Fenton to illustrate the designer intervented optimization process and to provide a comparison with the fully automated procedure of Pappas This designer intervented interactive program appears more effective and faster than the completely automated CADOP5 code on …

Measurement Of Thermal Conductivity Of Polymers Using Line Source Method, Manojkumar C. Patel

Theses

The purpose of this investigation was to evaluate the Line Source technique to measure the thermal conductivity of different molten polymers. Although the results obtained using this method are within acceptable experimental error limits, due to tec reasons explained, the results are not as accurate as claimed in the literature which describe this technique.

Deposition Of Particles In Horozontal Parallel Plate Channel Due To Image Charge, Inertia, Viscosity And Gravity, Chi-Young Chu

Theses

This investigation was made to determine the effect on the deposition of particle in a horizontal parallel-plate channel due to the influences of image charge, viscosity, inertia and gravity. The flow considered was lamina, incompressible and steady. The flow patterns considered were uniform and fully developed with symmetry about the axis of the channel.

The governing equations derived for a particle were based on Newton's Second Law of motion. Since the resulting governing equations are linear second order differential equations, Runge-Kutta algorithm is used to solve the problem and graphical techniques is used to interpret the results of the numerical …

Design Of Hvac Duct Stiffeners With Tie Rods, Raviraj Somayaji

Theses

"HVAC" ducts are made of thin gauge sheet metal. They are usually reinforced with transverse stiffeners. These stiffeners are usually made of hot rolled steel sections, such as equal leg angles or channels.

When the size of an "HVAC" duct exceeds 72 inches, additional stiffeners in the axial direction are used to reinforce the duct sheets. Tie rods are also installed, between the axial stiffeners, across the duct cross-section, to support these stiffeners. The "HVAC" ducts are subjected to either external or internal pressure. The transverse stiffeners have one or two tie rods installed, and they become statically indeterminate structures. …

An Experimental Investigation Of Round Normal Impinging Jet Of Water, Dipendra Saharay

Theses

The various flow parameters of round jets of water impinging normally on a flat plate are measured experimentally. The velocity and pressure distribution along the axis of the jet at various sections of the jet parallel to the horizontal lucite striking plate and along the impinging surface was found. The nozzles used were 1/4 inch and 1/2 inch in diameter. The Reynolds number based on the nozzle diameter was 15,000 to 25,000. The distance from the jet origin to the deflecting boundary ranged from thrice the diameter of the jet to twelve and sixteen times the diameter of the jet. …

On The Stability Of Columns Of Varying Cross-Sections, Vallanore K. Suresh

Theses

The purpose of this thesis is to study the stability of columns with axially varying cross-sections using approximate Methods. Much of the work has been done on the stability of the columns by using various techniques. This study, in part, verifies some of the above theories by Numerical Computations. Solutions for the optimal dimensions of columns to withstand a particular load without buckling are shown for a variety of columns,viz.,column bounded by linear taper, paraboloid of revolution and in general a column bounded by a curve of n'th degree.

The problem of columns of varying cross-sections can be solved by …

Experimental Investigation Of An Axisymmetric Air Jet Impinging On A Flat Plate, Saibal Basu

Theses

Experimental investigation was carried out on a circular, submerged, axisymmetric turbulent air jet-with normal impingement on a smooth, flat, square lucite plate, The flow was considered to be incompressible because the velocity of the jet was not too high, with Mach Number of the order of 0.3. Three nozzle diameters of 0.375" (9,525 mm), 0.250" (6.35 mm) and 0.125" (3.175 mm) were used with Reynolds number ranging from 7,000 to 70,000.

Various flow parameters were measured to obtain the velocity and pressure distributions at the surface of the flat lucite plate and along the centerline of the normal impinging air …

The Quasisteady Approach For Thermal Analysis Of Frost Action Below Refrigerated Warehouses, Milan Kumar Bag

Theses

The quasisteady method of analysis has been used to determine the frost depth below refrigerated warehouses. For the case when the ground temperature is different from phase change temperature, the solution is obtained by numerical integration of the equation governing the phase change process. When the ground temperature approaches the phase change temperature closed form solution is obtained. The results obtained from the quasisteady method compare well with the experimental results. The results presented in this thesis should find use in the design of the refrigerated warehouses in the colder regions of the world.

Simulation Of Rotational Molding, Hersel Ahdout

Theses

A computer program is written in FORTRAN IV to simulate the Rotational Molding process based on the discrete technique suggested by Progelhof and Throne. This program employs three techniques of Finite Difference, Euler's, Crank Nicolson's, and pure implicit, with their inherent accuracy and cost limits. The program has the capability of updating the variable parameters of polymer as the temperature rises, which eventuall leads to the closest simulation possible to the actual experiment.

Accuracy And Convergence Of Finite Element Approximations, Gwo-Tar Chang

Theses

In the design of structure, the engineer seeks to determine the distribution of stresses throughout the structure or the displacements at certain points of the structure. The finite element method is a numerical analysis technique for obtaining approximate solutions to engineering problems that are not amenable to closed form solutions.

In this work the triangular element and the rectangular element in plane stress are employed in the development of the formulation of element stiffness equations. The effect of the number of elements on the convergence to the analytical solution was investigated. Similar study using rectangular elements was also carried out …