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Acoustics, Dynamics, and Controls Commons™
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- Centrifugal-induced bowing patterns (1)
- Computational fluid dynamics (CFD) (1)
- Finite Elements (1)
- Finite elements (1)
- Flow characteristics (1)
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- Gear noise; Acoustic intensity; Vibration; Boundary element method; Sound power (1)
- Gear noise; Spur gears; Acoustic intensity; Sound power (1)
- Gears; Acoustic intensity ; Gear noise; Robotics; Vibration; Gear testing (1)
- Monte Carlo simulation (1)
- Multiphase counter-current flow (1)
- Nonlinear (1)
- Post combustion CO2 capture (1)
- Runge-Kutta (1)
- Statistical linearization (1)
- Stochastic (1)
- Vibration-assisted Drilling (1)
Articles 1 - 8 of 8
Full-Text Articles in Acoustics, Dynamics, and Controls
Leveling The Playing Field: Enacting Equitable Pedagogy To Teach Rigid Body Dynamics, Eleazar Marquez, Samuel Garcia
Leveling The Playing Field: Enacting Equitable Pedagogy To Teach Rigid Body Dynamics, Eleazar Marquez, Samuel Garcia
Mechanical Engineering Faculty Publications
Research examining the quality of engineering programs across different instructions of learning has revealed that no two programs are alike. Each program has unique and distinctive features that influence the quality and rigor of education that students receive. Institutional culture, leadership, faculty preparedness, funding and many other factors influence program quality. Additionally, researchers have also noted that many institutional gaps and equity related issues are persistent and troublesome facets that further exacerbate the academic gaps in STEM education. It is within this context, that students attending top tier universities will likely have remarkedly vast academic experiences in terms of level …
Estimation Of The Response, Power Spectra, And Whirling Patterns Generated From Mud Circulating Along The Annulus During Drilling Procedures: An Alternative Mathematical Representation Via Finite Element Modelling, Eleazar Marquez
Mechanical Engineering Faculty Publications
In this study, an alternative mathematical representation of a drill-string is proposed to provide an alternative assessment on BHA dynamic alterations. Lateral vibrations remain the focal point of drill-string breakdowns given their high frequency characterization and ability to deviate perforation trajectories from the subsurface target. In this paper, the proposed model consists of an anisotropic rotor subjected to distinct RPMs, an axial force, and a bidirectional harmonic excitation with specified amplitude and assorted duration to simulate annulus motion generated from the mud fluid. In this regard, Euler-Bernoulli beam theory was adopted to establish a complete MDOF mathematical expression and thus …
Development Of An Improved Mathematical Representation Which Captures The Nonlinear Dynamic Behavior Of A Drill-String Assembly, Eleazar Marquez
Development Of An Improved Mathematical Representation Which Captures The Nonlinear Dynamic Behavior Of A Drill-String Assembly, Eleazar Marquez
Mechanical Engineering Faculty Publications
In this study, an improved mathematical representation of a drill-string assembly is developed to provide an alternative assessment on vibration irregularities proliferating downhole due to bit-rock interference. Lateral vibrations receive particular attention due to their high frequency content which alter the dynamic response of the drill-string, instigate casing damage, and impede optimal penetration rates. The response of the drill-string is captured by synthesizing compatible stationary bit excitations, via an auto-regressive digital filter, and implementing Monte Carlo simulation, while the power spectral density function is approximated to elucidate the dynamic characteristics during drilling. Formulating adequate physical parameters for the equation of …
A Probabilistic Analysis In Vibration-Assisted Drilling To Measure Dynamic Behavior During Drilling And Understand Risk Factors, Eleazar Marquez, Samuel Garcia
A Probabilistic Analysis In Vibration-Assisted Drilling To Measure Dynamic Behavior During Drilling And Understand Risk Factors, Eleazar Marquez, Samuel Garcia
Mechanical Engineering Faculty Publications
In this paper, a mathematical representation is proposed to further understand the dynamic behavior and risk factors associated with vibration-assisted drilling (VAD) technology. The proposed Timoshenko beam model, which characterizes VAD technology, consists of two passive, counter-rotating coaxial rotors operating simultaneously, subjected to a stochastic excitation. In this regard, a finite element technique was incorporated to determine the physical parameters of the governing equation of motion, where the shear and rotary effects, as well as the gyroscopic couples generated perpendicular to the axis of rotation, were accounted for. Further, the relative velocity between the coaxial rotors was accounted in the …
3d Numerical Study Of Multiphase Counter-Current Flow Within A Packed Bed For Post Combustion Carbon Dioxide Capture, Li Yang, Fang Liu, Zhengchang Song, Kunlei Liu, Kozo Saito
3d Numerical Study Of Multiphase Counter-Current Flow Within A Packed Bed For Post Combustion Carbon Dioxide Capture, Li Yang, Fang Liu, Zhengchang Song, Kunlei Liu, Kozo Saito
Mechanical Engineering Faculty Publications
The hydrodynamics within counter-current flow packed beds is of vital importance to provide insight into the design and operational parameters that may impact reactor and reaction efficiencies in processes used for post combustion CO2 capture. However, the multiphase counter-current flows in random packing used in these processes are complicated to visualize. Hence, this work aimed at developing a computational fluid dynamics (CFD) model to study more precisely the complex details of flow inside a packed bed. The simulation results clearly demonstrated the development of, and changes in, liquid distributions, wetted areas, and film thickness under various gas and liquid …
Effect Of Operating Conditions On Gearbox Noise, Fred B. Oswald, James J. Zakrajsek, Dennis P. Townsend, William Atherton, Hsiang Hsi Lin
Effect Of Operating Conditions On Gearbox Noise, Fred B. Oswald, James J. Zakrajsek, Dennis P. Townsend, William Atherton, Hsiang Hsi Lin
Mechanical Engineering Faculty Publications
Low-contact-ratio spur gears were tested in the NASA gear noise rig to study the noise radiated from the top of the gearbox. The measured sound power from the gearbox top was obtained from a near-field acoustic intensity scan taken at 63 nodes just above the surface. The sound power was measured at a matrix of 45 operating speeds and torque levels. Results are presented in the form of a spectral speed map and as plots of sound power versus torque (at constant speed) and as sound power versus speed (at constant torque) Because of the presence of vibration modes, operating …
Comparison Of Analysis And Experiment For Gearbox Noise, Fred B. Oswald, A. F. Seybert, T. W. Wu, William J. Atherton
Comparison Of Analysis And Experiment For Gearbox Noise, Fred B. Oswald, A. F. Seybert, T. W. Wu, William J. Atherton
Mechanical Engineering Faculty Publications
Low-contact-ratio spur gears were tested in the NASA gearnoise rig to study the noise radiated from the top of the gearbox. Experimental results were compared with a NASA acoustics code to validate the code for predicting transmission noise. The analytical code is based on the boundary element method (BEM) which models the gearbox top as a plate in an infinite baffle. Narrow-band vibration spectra measured at 63 nodes on the gearbox top were used to produce input data for the BEM model. The BEM code predicted the total sound power based on this measured vibration. The measured sound power was …
Automated Acoustic Intensity Measurements And The Effect Of Gear Tooth Profile On Noise, William J. Atherton, Adam Pintz, David G. Lewicki
Automated Acoustic Intensity Measurements And The Effect Of Gear Tooth Profile On Noise, William J. Atherton, Adam Pintz, David G. Lewicki
Mechanical Engineering Faculty Publications
Acoustic intensity measurements were made at NASA Lewis Research Center on a spur gear test apparatus. The measurements were obtained with the Robotic Acoustic Intensity Measurement System developed by Cleveland State University. This system provided dense spatial positioning, and was calibrated against a high quality acoustic intensity system. The measured gear noise compared gearsets having two different tooth profiles. The tests evaluated the sound field of the different gears for two speeds and three loads. The experimental results showed that gear tooth profile had a major effect on measured noise. Load and speed were found to have an effect on …