Mechanical Engineering Commons^™

A Kalina Cycle Application For Power Generation, Mounir B. Ibrahim, Ronald M. Kovach

Mechanical Engineering Faculty Publications

A multi-component (NB₃/H₂O) Kalina-type cycle that utilizes the exhaust from a gas turbine is investigaed in this paper. The turbine-inlet pressure of 5.96 × 10⁶N/m² and temperature of 755.372 K were kept constant, as well as the working fluid temperature at the condenser outlet (at 290K). The HN₃ mass fraction at the turbine inlet was varied along with the seperator temperature and the effects on the cycle efficiency were studied. The relationships between turbine-inlet flow and the seperator-inlet. How are shown in addition to the upper and lower HN₃ mass-fraction bounds. …

Transient Flowmeter Calibration Facility, Paul J. Lefebvre, William W. Durgin

Office of the Provost Scholarship

An apparatus for defining the free surface of a moving column of a fluid in a vertical pipe to enhance the accuracy of measurements of transient rate of flow of the fluid using electromagnetic flowmeter is described. It provides a neutrally buoyant plug which stays in contact with the free surface of the column of the fluid at all times and thus defines the free surface of the fluid moving in the vertical pipe accurately and reduces the oscillations of the free surface of the fluid.

Advanced Aeronatics Design: Project Based Engineering Education At Wpi, D. J. Olinger, William W. Durgin, Andreas N. Alexandrou

Office of the Provost Scholarship

One element of WPI's project-based curriculum is its interdisciplinary Advanced Aeronautics Design Program. Students participating in the program are involved in the design, construction, and flight testing of non-traditional aircraft such as an ultralight solar-powered vehicle, microwave-powered long endurance aircraft, or a flying oblique wing. The WPI project philosophy and character are described and illustrated using examples from the AAD program.

Laboratory Testing Of The Reflectance Properties Of Roofing Materials, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Past simulation and test cell studies have shown potential reduction to building cooling loads from higher exterior surface solar reflectances (Givoni and Hoffman, 1968; Givoni, 1976; Chuan and Busching, 1983; Griggs and Shipp, 1988; Anderson, 1989; Akbari et al., 1990; Chandra and Moalla, 1991; Bansal et al., 1992). Furthermore, simulation analysis of macro-climatic effects have shown that light colored surfaces may reduce the magnitude of the urban heat island (Taha et al., 1988; Akbari et al, 1989; Akbari et al., 1992).

Figure 1 shows a graphic illustration of the potential influence of surface reflectance on roof solar heat gain. The …

Analysis Of Sandwich Plates Subjected To Blast Loading, Vijay Prasad Bulla

Masters Theses

A dynamic analysis is presented for the bending response of square sandwich plates with isotropic core and facings under blast type pressure. The maximum central deflections of simply supported plates under static and dynamic loadings are compared for various thicknesses and elastic moduli. The deviation of the thick sandwich plate results from the pure-bending theory results is presented for various core properties. Small deflection dynamic iso-response plots are shown for different core rigidities. To study the limits of small deformation linearity for various sandwich plates, non-linear results for deformations under high pressure loads are compared with the linear results. The …

Rolling Friction Research Instrument, John P. Ward

Masters Theses

An instrument has been analyzed, designed and constructed that will accurately measure the rolling resistance of metallic spheres an plane surfaces subjected to normal loading which will produce contact stresses approaching material yield.

Numerical Analysis Of The Pullout Problem Of A Fiber Embedded In A Matrix : Comparison With An Approximate Analytical Solution, Ivan Enrique Esparragoza

FIU Electronic Theses and Dissertations

The classical problem of pullout of a long elastic rectilinear round bar (fiber) embedded in an elastic half-space (matrix) is considered before and while local debonding occurs. An approximate analytical solution derived from the elasticity theory, the intuitive Saint Venant's principle, the idea of boundary layer in hydrodynamics, and invariant Γ-integrals is presented. The problem is analyzed numerically by means of the finite element method using the ANSYS program. The cases of loading before and after the initiation of the debonding are studied. Both approaches, analytical and numerical, are compared in order to establish the concidence between them. The discrepancy …

Wet Process For Fly Ash Beneficiation, Jiann-Yang Hwang

Michigan Tech Patents

A wet process for the beneficiation of a fly ash by-product has the following steps: a) forming a slurry mixture of a fly ash material and a liquid; b) gravitationally separating and collecting a first material fraction of the fly ash having a density less than the liquid by skimming off floating slurry material; c) separating a first magnetic fraction from the slurry by subjecting the slurry to a magnetic field of from about 300 gauss to about 10 kilogauss; d) separating the unbumed carbon from the remaining slurry components by adding an effective amount of an oil having a …

Exergetic Cost Analysis Of A Mechanical Exergy Recycle, Jim Mcgovern

Conference Papers

A mechanical plant that involves an exergy recycle is presented for analysis. It consists of gearboxes and a fluid coupling. There is one input of shaft power to the plant and there are three separate outputs of shaft power. An exergetic cost analysis approach is outlined and applied to the plant.

Variable Structure End Point Control Of A Flexible Manipulator, Shailaja Chenumalla, Sahjendra N. Singh

Electrical & Computer Engineering Faculty Research

We treat the question of control and stabilization of the elastic multibody system developed in the Phillips Laboratory, Edwards Air Force Base, California. The controlled output is judiciously chosen such that the zero dynamics are stable or almost stable. A variable structure control (VSC) law is derived for the end point trajectory control. Although, the VSC law accomplishes precise end point tracking, elastic modes are excited during the maneuver of the arm. A Linear stabilizer is designed for the final capture of the terminal state.

A Vacuum Four-Ball Tribometer To Evaluate Liquid Lubricants For Space Applications, Masabumi Masuko, William R. Jones Jr, Ralph Jansen, Ben Ebihara, Stephen V. Pepper, Larry S. Helmick

Science and Mathematics Faculty Publications

The design and operation of a vacuum tribometer, based on the four-ball configuration, is described. This tribometer evaluates the tribological characteristics of liquid lubricants for space applications. Operating conditions include: room temperature, loads to approximately 1000N, speeds to approximately 500 rpm, and pressures of approximately 10(exp -6)Pa. Tests can also be run at atmospheric pressure with air or nitrogen. Some typical test results are included.

Boundary Layer Influences On The Subsonic Near-Wake Of A Family Of Three-Dimensional Bluff Bodies, Charles Willliam Alcorn

Mechanical & Aerospace Engineering Theses & Dissertations

A study is reported on subsonic bluff body near-wake flows. It has been determined that one family of bluff bodies, namely slanted-base ogive cylinders, can experience either a closed recirculating near-wake, or a longitudinal vortex near-wake depending on the base slant-angle and the Reynolds number. This suggests a dependence of near-wake parameters on the state of the boundary layer ahead of separation. This report addresses the influence of the boundary layer on the near-wake of slanted-base bluff bodies. Experiments were conducted in two facilities, the 6-inch Magnetic Suspension and Balance System (MSBS) at NASA Langley Research Center and the Old …

Studies On Nonequilibrium Phenomena In Supersonic Chemically Reacting Flows, Rajnish Chandrasekhar

Mechanical & Aerospace Engineering Theses & Dissertations

This study deals with a systematic investigation of nonequilibrium processes in supersonic combustion. The two-dimensional, elliptic Navier-Stokes equations are used to investigate supersonic flows with nonequilibrium chemistry and thermodynamics, coupled with radiation, for hydrogen-air systems. The explicit, unsplit MacCormack finite-difference scheme is used to advance the governing equations in time, until convergence is achieved.

For a basic understanding of the flow physics, premixed flows undergoing finite rate chemical reactions are investigated. Results obtained for specific conditions indicate that the radiative interactions vary substantially, depending on reactions involving HO$\sb2$ and NO species, and that this can have a noticeable influence on …

Fiber Enhanced Viscoelastic Damping Polymers And Their Application To Passive Vibration Control, Houchun Xia

Mechanical & Aerospace Engineering Theses & Dissertations

A new composite damping material is investigated, which consists of a viscoelastic matrix and high elastic modulus fiber inclusions. This fiber enhanced viscoelastic damping polymer is intended to be applied to light-weight flexible structures as surface treatment for passive vibration control. A desirable packing geometry for the composite material is proposed, which is expected to produce maximum shear strain in the viscoelastic damping matrix. Subsequently, a micromechanical model is established in which the effect of fiber segment length and relative motion between neighboring fibers are taken into account. Based on this model, closed form expressions for the effective storage and …

Finite Element Analysis For An Involute Spur Gear Noise Excitation By Impact Effects, Wenbeen Li

Electronic Theses & Dissertations

The purpose of this study includes (1) to identify the relationship between the impact loads or backlash and the sound field pressure of impact direct noise of meshing gears, (2) to show that impact whether or not the impact direct noise contributes to the noise of overall gear system, and (3) to demonstrate how impact direct noise can be predicted. The method used to predict was finite element analysis and numerical solution. This research presents the analytical model of impact direct noise prediction for meshing gear teeth based on the data that the tooth vibration and surface are known by …

Single Scheduling Problem With Dependent Setup Cost, Mohamed Mahmoud Zaki

Archived Theses and Dissertations

No abstract provided.

Numerical Study Of Spray Flame Characteristics, C.Y. Lin

Journal of Marine Science and Technology

A numerical method was considered to calculate spray flame structure and emissions characteristics. The turbulence fluctuation was predicted using k-e-g and algebraic mixing-length-hypothesis (mlh) turbulence models. The numerical method was evaluated using a set of available experimental data. It is shown that this theoretical model predicts the data well in the near nozzle region and the predictions improve quantitatively along the axial distance. In comparing the turbulence models, the k-e-g model provides a better result for the varying-density flow of spray combustion.

Vibration Suppression Of Beam Structures Traversed By Multiple Moving Loads Using A Damped Absorber, Y.H. Lin, C.H. Cho

Journal of Marine Science and Technology

This paper deals with the dynamic analysis of a simply supported beam subjected to multiple discrete and distributed moving loads. Resonant vibration is observed for the support beam traversed by multiple discrete moving loads. A practical scheme is applied to reduce the excessive beam vibration to an acceptable range by using a damped absorber attached at the beam center. Lagrange's equation is used to formulated the system governing equation and Laplace transformation is applied to derive the dynamic responses for both the beam and the absorber, Various design parameters, such as the mass ratio, the tuning ratio, and the damping …

Second Law Analysis On Ejection Cooling System, S.P. Liaw, Y.H. Chang

Journal of Marine Science and Technology

Ejection cooling system is analyzed by the second law of thermodynamics in this study. It is mainly consisted of a boiler, an ejector, an expansion device, a condenser, and an evaporator. Special focus is stressed on the variation of exergy in each component. The working refrigerant received exergy from boiler and pump and cons umed in other parts of the system. The coefficients of performance based on both the first and the second laws are computed respectively and thus the changes of energy and exergy in each component of the system can be readily understood. In addition, the boiler temperature, …

Analysis And Simulation Of Solidification For Phase Change Materials In A Cylindrical Container, H.C. Tien, J.S. Chang

Journal of Marine Science and Technology

The objective of this paper is to study the solidification problem of the phase change materials (PCM) in a thick-walled cylindrical container. Through varying each controlling parameter such as the thermophysical properties of wall (mold), wall thickness, aspect ratio of the container, initial temperature of PCM and the external cooling conditions, etc., the effect of each parameter on the solidification process is shown clearly. By knowing how a thick wall interacts with such a phase change phenomenon, it is therefore possible to well control the solidification process and also to improve the solid structure formed. In this study, convective boundary …

Formation Of Amorphous Cu-Zr Alloy Powder By Mechanical Alloying, T.R. Chen, P.Y. Lee

Journal of Marine Science and Technology

Amorphous Cux Zr100-x alloy powder has been synthesized in the range 20 ≦ x ≦ 80 by mechanical alloying mixtures of Cu and Zr powders. This range is larger than amorphous alloys produced by the vaporquenching technique. A mixture of amorphous and crystalline phases formed at the compositions of Cu10Zr90 and Cu90Zr10. Amorphous CuxZr100-x alloy powder also has been synthesized in the range 20 ≦ X ≦ 60 by mechanical alloying mixtures of intermetallic compound Cu9Zr2 and CuZr2 powders. The temperature and activation energy for crystallization of the MA Cu-Zr amorphous powders are higher than that for vaporquenched samples. The …

Aluminum Electrodeposition From Room Temperature Molten Alcl3-Bpc Salt Bath, C.C. Yang, C.P. Chang

Journal of Marine Science and Technology

The characteristics of aluminum electrodeposited layer from an ambient temperature molten salt were discussed in this study. The experimental results indicated that it is possible to carry out aluminum electrodeposition on the surface of brass and stainless steel when binary AlCI3-8P C molten electrolysis were used. The morphology of the components, characteristics and images can be detected by SEM, Auger Analysis, X-ray diffraction analysis and electrochemical polarization curves. The denser and more adhesive electrodeposited aluminum layer can be achieved by chosing proper electrolyte components (AlCI3: BPC-acidic salt bath), current forms (D.C./pulse), current density, electrolytic time and other pretreatment. In addition, …

Optimization Of The Seating Position In A Human-Powered Vehicle, Y. Lei, Mohamed Trabia, D. Too

Mechanical Engineering Faculty Research

Until recently, most of the human-powered vehicles (HPV) were designed focusing solely on its aerodynamics characteristic. In many of these HPV designs, the rider seating position was arbitrarily chosen without consideration of its effect on the rider's comfort and cycling effectiveness. Also, there is no guarantee that the seating position is related to maximum power output. Too (1991) used an experimental approach to determine that the rider will produce the maximum anaerobic power when the seat tube angle of a bicycle is at 75° whereas Hull and Gonzalez (1990) used an engineering approach to optimize the cycling biomechanics. However several …

Nonlinear Dynamic Finite Element Simulation Of Hydroelastic Mounts For Light Weight Vehicles, Talla Jayapal Reddy

Masters Theses

Modern light weight vehicles generate large noise levels, that may need bulky classical rubber mounts to suppress. Hydroelastic mounts can significantly reduce the vibration level of current production automobiles without weight penalty. However, the highly nonlinear behavior of hydroelastic mounts has not been established yet and its use is, therefore, limited to trial and error design methods.

This study discusses the implementation of nonlinear finite element simulation of hydroelastic mounts using the ANSYS finite element code. Fluid elements are limited to linear analysis and therefore are incompatible with the nonlinear hyperelastic elements. A method is proposed to simulate the fluid …

On Orthogonal Collocation Solutions Of Partial Differential Equations, Herli Surjanhata

Dissertations

In contrast to the h-version most frequently used, a p-version of the Orthogonal Collocation Method as applied to differential equations in two-dimensional domains is examined. For superior accuracy and convergence, the collocation points are chosen to be the zeros of a Legendre polynomial plus the two endpoints. Hence the method is called the Legendre Collocation Method. The approximate solution in an element is written as a Lagrange interpolation polynomial. This form of the approximate solution makes it possible to fully automate the method on a personal computer using conventional memory.

The Legendre Collocation Method provides a formula for …

Coordinate Measuring Machines : A Modern Inspection Tool In Manufacturing, Matthias Richard Mantel

Theses

Coordinate Measuring Machines (CMM) are flexible and universal dimensional measuring devices with the capability for full integration into a CIM information network. Developed as highly precise measuring machines for specially designed measuring rooms, today's CMMs are more and more used in shop floor applications which is a hostile environment for a precise measuring tool. CMMs are offered in a variety of configurations and levels of automation. For the CMM buyer it is therefore essential to have an overview of the different types of CMMs and their subsystems before making a purchasing decision.

To obtain reliable measuring results that are used …

Design And Development Of Flexible Manufacturing Cells - A Case Study, Behrouz Barzani

Theses

This paper covers the typical ills of American manufacturing companies and provides steps to selecting a flexible manufacturing cell(s) or system as a remedy. For that reason various definition of different types of flexibilities in manufacturing and the interrelationships between the several types have been examined. In addition, their purposes, means of obtaining them and some measurement and evaluations has been discussed. This was done to cover the basic but necessary requirements for understanding and selecting a flexible manufacturing system. Finally, the design process of a flexible system and its intuitive justification were discussed.

Simulation Of Manufacturing Cell Using Hoops Graphic Software And Siman Simulation Language, Parikh Vipul

Theses

Control of jobs being processed in manufacturing shop floor is important to management. The performance of job shop is affected by shop congestion due to arrival rate, batch size, number of machines, buffer capacity, process time variation, and dispatching rules use to load the jobs on the machine.

The job shop is a very complex system and hence, it is difficult as well as time consuming to obtained result using analytical method. A SIMAN simulation language is used to create generic model of a manufacturing cell and simulation analysis of those parameters variation such as job shop efficiency, the average …

Geometric Dimensioning And Tolerancing A Tool For Concurrent Engineering, Tapan Kumar S. K. Jain

Theses

The concept of Concurrent Engineering recognizes an immediate need for a new design environment and technology and so requires extensive interdisciplinary cooperation and integration of diverse functions of a manufacturing organization such as marketing, design, manufacturing and finance. One of the key factors to achieve successful integration among the departments is better communication and it becomes imperative in cases of varying levels of communication needs, especially in interdepartmental cases.

Concurrent Engineering is a philosophy which provides certain benefits. There are various tools and methods available for implementation of Concurrent Engineering concepts. One of the tools is Geometric Dimensioning & Tolerancing …

A Simulation Of A Monitoring And Alarm System In An Energy Management System, Hui-Jen Liu

Theses

This is a simulation for an energy system's monitoring and alarm and working under KEE's environment. Because of KEE's powerful capabilities, we can monitor and get warning signals from several active windows that we attaching them from KEE's system knowledge base to our source code.

It is very convenient for us to set every member of the energy system on an image panel. We can monitor the entire conditions of that member and get highlighted warning signals from its own image panel. Also we can initialize them by a kind of method-actuators windows if we want to restore the system.