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Full-Text Articles in Aerospace Engineering
Local Field Effects On Magnetic Suppression Of The Converging Richtmyer-Meshkov Instability, Vincent Wheatley, Wouter Mostert, D. M. Bond, Ravi Samtaney
Local Field Effects On Magnetic Suppression Of The Converging Richtmyer-Meshkov Instability, Vincent Wheatley, Wouter Mostert, D. M. Bond, Ravi Samtaney
Mechanical and Aerospace Engineering Faculty Research & Creative Works
We examine how the suppression of the converging shockdriven Richtmyer-Meshkov instability by an applied magnetic field is dependent on the local magnetic field strength and orientation. In particular, we examine whether the extent of suppression can be reasonably predicted by a linear model for the planar case. This is done for cylindrically converging cases with a high perturbation wavenumber and two different initial magnetic field configurations.
Effect Of Amino-Functionalization On Insulin Delivery And Cell Viability For Two Types Of Silica Mesoporous Structures, Abdollah Zakeri Siavashani, Masoumeh Haghbin Nazarpak, Fateme Fayyazbakhsh, Tayebeh Toliyat, Steven James Peter Mcinnes, Mehran Solati-Hashjin
Effect Of Amino-Functionalization On Insulin Delivery And Cell Viability For Two Types Of Silica Mesoporous Structures, Abdollah Zakeri Siavashani, Masoumeh Haghbin Nazarpak, Fateme Fayyazbakhsh, Tayebeh Toliyat, Steven James Peter Mcinnes, Mehran Solati-Hashjin
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Inorganic Mesoporous Structures Are a Class of Novel Biomaterials that Have Shown Practical Applications in Delivery of a Variety of Therapeutic Agents. in the Present Study, Two Mesoporous Structures Were Prepared, and the Effect of Surface Modification on their Insulin Delivery and in Vitro Cytotoxicity Was Evaluated. Morphological and Structural Characterizations of Silica Particles Were Accomplished by Different Analytical Techniques, Including Scanning Electron Microscopy, X-Ray Diffraction, Fourier Transform Infrared Spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) Surface Area Analyses. the Drug Loading Capacity and in Vitro Drug Release Behavior of Silica Structures Were Investigated under Simulated Gastrointestinal Conditions and Phosphate-Buffered Saline Solution …
Numerical Modeling Of Dust Dynamics Around Small Asteroids, William Yu, Joseph J. Wang, Daoru Frank Han
Numerical Modeling Of Dust Dynamics Around Small Asteroids, William Yu, Joseph J. Wang, Daoru Frank Han
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Dynamics of dust transport around an airless body has been a focused area of research in recent years, however, various challenging aspects still remain to be addressed. This paper presents an investigation of charged dust transport and distribution around small asteroids utilizing a full particle Particle-in-Cell (PIC) model to simulate plasma flow around an asteroid and calculate surface charging self-consistently from charge deposition on asteroid. Material properties of asteroid are also explicitly included in the simulation. PIC simulation results are fed into a 3D dust dynamics model to simulate charged dust levitation, transport and distribution. In addition to electrostatic and …
Experimental And Numerical Investigations Of Dust Effects On Surface Charging In Plasma, Kevin Chou, Daoru Frank Han, Joseph J. Wang
Experimental And Numerical Investigations Of Dust Effects On Surface Charging In Plasma, Kevin Chou, Daoru Frank Han, Joseph J. Wang
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A series of 3-D, fully kinetic particle-in-cell (PIC) simulations were performed to simulate mesothermal plasma flow self-consistently with surface charging. Simulation results of plasma charging of a conducting surface covered by a thin dust layer in a plasma of cold ions and thermal electrons are presented. The surface potentials and potentials inside the dust layer are compared with experimental results. Results show that a layer of dust over a conducting surface creates a capacitance, which drives the surface more negative with respect to the ambient plasma.
High-Frequency Instabilities Of Stationary Crossflow Vortices In A Hypersonic Boundary Layer, Fei Li, Meelan Choudhari, Pedro Paredes-Gonzalez, Lian Duan
High-Frequency Instabilities Of Stationary Crossflow Vortices In A Hypersonic Boundary Layer, Fei Li, Meelan Choudhari, Pedro Paredes-Gonzalez, Lian Duan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Hypersonic boundary layer flows over a circular cone at moderate incidence angle can support strong crossflow instability in between the windward and leeward rays on the plane of symmetry. Due to more efficient excitation of stationary crossflow vortices by surface roughness, such boundary layer flows may transition to turbulence via rapid amplification of the high-frequency secondary instabilities of finite-amplitude stationary crossflow vortices. The amplification characteristics of these secondary instabilities are investigated for crossflow vortices generated by an azimuthally periodic array of roughness elements over a 7° half-angle circular cone in a Mach 6 free stream. The analysis is based on …
Analysis Of The Gauss-Bingham Distribution For Attitude Uncertainty Propagation, Jacob E. Darling, Kyle J. Demars
Analysis Of The Gauss-Bingham Distribution For Attitude Uncertainty Propagation, Jacob E. Darling, Kyle J. Demars
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Attitude uncertainty quantification typically requires a small angle assumption, and thus an inherent small uncertainty assumption, to be made. This small angle assumption can be eliminated by employing the Bingham distribution to represent the attitude uncertainty in the attitude quaternion directly. Moreover, an extension to the Bingham distribution, termed the Gauss-Bingham distribution, can be used to represent correlated attitude quaternion and angular velocity uncertainty to enable attitude uncertainty propagation. In order to evaluate the potential accuracy gain using the Gauss-Bingham distribution for attitude uncertainty quantification, the Gauss-Bingham distribution method for attitude uncertainty propagation is compared to the propagation step of …
Continuum And Molecular-Dynamics Simulation Of Nanodroplet Collisions, Raunak Bardia, Zhi Liang, Pawel Keblinski, Mario F. Trujillo
Continuum And Molecular-Dynamics Simulation Of Nanodroplet Collisions, Raunak Bardia, Zhi Liang, Pawel Keblinski, Mario F. Trujillo
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The Extent to Which the Continuum Treatment Holds in Binary Droplet Collisions is Examined in the Present Work by using a Continuum-Based Implicit Surface Capturing Strategy (Volume-Of-Fluid Coupled to Navier-Stokes) and a Molecular Dynamics Methodology. the Droplet Pairs Are Arranged in a Head-On-Collision Configuration with an Initial Separation Distance of 5.3 Nm and a Velocity of 3 Ms-1. the Size of Droplets Ranges from 10-50 Nm. Inspecting the Results, the Collision Process Can Be Described as Consisting of Two Periods: A Preimpact Phase that Ends with the Initial Contact of Both Droplets, and a Postimpact Phase Characterized by the Merging, …
Drag Reduction Utilizing Driven Micro-Cavities, David W. Riggins
Drag Reduction Utilizing Driven Micro-Cavities, David W. Riggins
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A high-speed vehicle or device presents a surface configured to move through a fluid such that the fluid flows across the surface in a primary flow direction. The vehicle or device also presents a subsurface spaced inwardly from the surface, as well as a plurality of cavity-defining structures that project generally outwardly from the subsurface and extend along the subsurface generally transverse to the primary flow direction. The cavity-defining structures are spaced apart in the primary flow direction. Each adjacent pair of the cavity-defining structures and the subsurface at least in part cooperatively define a cavity therebetween. Fluid rollers or …
Sound Attenuation In Amorphous Silica At Frequencies Near The Boson Peak, Zhi Liang, Pawel Keblinski
Sound Attenuation In Amorphous Silica At Frequencies Near The Boson Peak, Zhi Liang, Pawel Keblinski
Mechanical and Aerospace Engineering Faculty Research & Creative Works
We Use Molecular Dynamics Phonon Wave Packet (WP) Simulations to Study Acoustic Propagation and Attenuation in Amorphous Silica (A-SiO2) at Frequencies Near the Boson Peak (BP) Position and Compare Them with the Results of Equilibrium Molecular Dynamics (EMD) Simulations. the Sound Attenuation Coefficients Obtained from WP Simulations Are Generally Consistent with Those from EMD Predictions and Have Reasonable Agreement with the Existing Experimental Data. Near the BP Position, We Found the Frequency-Dependent Sound Attenuation Coefficients for Longitudinal and Transverse Modes Both Follow the Rayleigh-Scattering Fourth Power Law. above the BP Frequency, However, the Propagating Phonon is Essentially Attenuated …
Geometric Consideration Of Nanostructures For Energy Storage Systems, Jonghyun Park, Jie Li, Wei Lu, Ann Marie Sastry
Geometric Consideration Of Nanostructures For Energy Storage Systems, Jonghyun Park, Jie Li, Wei Lu, Ann Marie Sastry
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Battery performance and its fade are determined by various aspects such as the transport of ions and electrons through heterogeneous internal structures; kinetic reactions at the interfaces; and the corresponding interplay between mechanical, chemical, and thermal responses. The fundamental factor determining this complex multiscale and multiphysical nature of a battery is the geometry of active materials. In this work, we systematically consider the tradeoffs among a selection of limiting geometries of media designed to store ions or other species via a diffusion process. Specifically, we begin the investigation by considering diffusion in spheres, rods, and plates at the particle level, …
Silicon-Wall Interfacial Free Energy Via Thermodynamics Integration, Wan Shou, Heng Pan
Silicon-Wall Interfacial Free Energy Via Thermodynamics Integration, Wan Shou, Heng Pan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
We compute the interfacial free energy of a silicon system in contact with flat and structured walls by molecular dynamics simulation. The thermodynamics integration method, previously applied to Lennard-Jones potentials [R. Benjamin and J. Horbach, J. Chem. Phys. 137, 044707 (2012)], has been extended and implemented in Tersoff potentials with two-body and three-body interactions taken into consideration. The thermodynamic integration scheme includes two steps. In the first step, the bulk Tersoff system is reversibly transformed to a state where it interacts with a structureless flat wall, and in a second step, the flat structureless wall is reversibly transformed into an …
Ionic And Electronic Conductivities Of Atomic Layer Deposition Thin Film Coated Lithium Ion Battery Cathode Particles, Rajankumar L. Patel, Jonghyun Park, Xinhua Liang
Ionic And Electronic Conductivities Of Atomic Layer Deposition Thin Film Coated Lithium Ion Battery Cathode Particles, Rajankumar L. Patel, Jonghyun Park, Xinhua Liang
Mechanical and Aerospace Engineering Faculty Research & Creative Works
It is imperative to ascertain the ionic and electronic components of the total conductivity of an electrochemically active material. A blocking technique, called the “Hebb-Wagner method”, is normally used to explain the two components (ionic and electronic) of a mixed conductor, in combination with the complex ac impedance method and dc polarization measurements. CeO2 atomic layer deposition (ALD)-coated and uncoated, LiMn2O4 (LMO) and LiMn1.5Ni0.5O4 (LMNO) powders were pressed into pellets and then painted with silver to act as a blocking electrode. The electronic conductivities were derived from the currents obtained using …