Engineering Commons^™

Vibration Analysis Of A Fan/Compressor Blade, Daisaku Inoyama

Master's Theses - Daytona Beach

The vibration of blades in gas turbine engines has become an important issue during the last decade because of its significant impact on high cycle fatigue failure due to resonant vibrations. The main objective of this thesis is the vibration analysis of compressor/fan blade using three-dimensional finite element analysis together with various analytical approaches. First, the analytical solutions were established using various analytical methods, Bernoulli-Euler, Rayleigh, Rayleigh-Ritz, two-dimensional plate, and Timoshenko beam methods. Then, the vibration behaviors of the blade are analyzed in full extent using commercially available finite element solver, MSC.NASTRAN, and correlated with the analytical solutions. The finite …

A Full-Wave Investigation Of The Use Of A 'Cancellation Factor' In Gw-Airglow Interaction Studies, Yonghui Yu

Master's Theses - Daytona Beach

Atmospheric gravity waves (GWs) perturb minor species involved in the chemical reactions of airglow emissions in the mesopause region of the earth's atmosphere. The so-called 'Cancellation Factor' (CF) is defined as a transfer function relating the amplitude of airglow brightness fluctuation to the amplitude of GW-induced fluctuation in temperature [Swenson and Gardner, 1998]. This transfer factor can be used to determine GW fluxes and the forcing effects of GWs on the mean state through airglow observations, because GW fluxes are proportional to the square of GW amplitude.

Numerical models [Walterscheid et al., 1987; Schubert et al., 1991] have previously shown …

An Original Method For Computing Complex Non-Premixed Flows In Chemical Equilibrium, Raphael Cioffl

Master's Theses - Daytona Beach

A novel method for computing chemical equilibrium reactions in three-dimensional reacting fluid flows is introduced in this paper. The originality of the method is that continuity equations are solved for the atomic densities rather than for the molecular species densities, as is the case for non-equilibrium flow calculations. The method is suited for applications to mixing flows in rocket engine combustors, where, due to the typical low convective speed, chemical reaction is best modeled as an equilibrium process. Equilibrium formulations usually describe the flow as a perfect, atomically uniform mix between the fuel and the oxidizer. This assumption tends to …

Numerical Analysis Of An Airfoil Response To An Impinging Gust, Claire M. Lessiau

Master's Theses - Daytona Beach

The BASS code, a nonlinear high-order prefactored compact code is validated on a benchmark problem. The nonlinear response of a loaded airfoil to an impinging vertical gust is investigated in the parametric space of gust intensity and frequency. Computational resources, involving a Linux cluster, were set up and maintained. The code was corrected and adapted to this particular problem. Results are compared with linear solution from the GUST3D solver.

Development Of A Force And Airspeed Data Acquisition System For The Embry-Riddle Aeronautical University 30x40 In. Subsonic Wind Tunnel, Toon Hong Foo

Master's Theses - Daytona Beach

The very first objective of performing most experiments is collecting numerical data. Values can be read from instruments or gauges by eye and recorded by hand. However, in certain experiments the amount of data collected may become so large that a human alone can not observe and record the data fast enough. This is where a data acquisition system comes into play. A data acquisition system is a network of devices that collects data from instruments and outputs it to hard copies or storage devices. A data acquisition system can also control instruments to take the data at the exact …

Residual Compressive Strength Prediction Of Carbon/Epoxy Laminates Subjected To Low Velocity Impact Damage, Christopher D. Hess

Master's Theses - Daytona Beach

Low energy impact damage to a composite structure is difficult to detect and can have profound effects on compressive strengths. Low energy impact damage is sometimes termed as barely visible impact damage (BVID). Detecting BVID is only possible by implementing nondestructive testing (NDT) techniques. Depending upon the support conditions, material system, laminate thickness, lay-up orientation, and impactor geometry, velocity, and hardness, the types of damage associated with BVID include delaminations, longitudinal and transverse matrix cracks, and in some cases, fiber breaks. Material properties such as the strengths of the matrix, fibers, fiber/matrix interface, and more important for BVID, ply interface …

The Effectiveness Of Monitor-Based Augmented Reality Paradigms For Learning Space-Related Technical Tasks, Christopher Michael Opalenik

Master's Theses - Daytona Beach

Currently today there are many types of media that can help individuals learn and excel in the on going effort to acquire knowledge for a specific trait or function in a workplace, laboratory, or learning facility. Technology has advanced in the fields of transportation, information gathering, and education. The need for better recall of information is in demand in a wide variety of areas. Augmented reality (AR) is a technology that may help meet this demand. AR is a hybrid of reality and virtual reality (VR) that uses the three-dimensional location viewed through a video or optical see-through media to …