Calculation of Nano-Sized Particle Catcher by Ultrasonic Vibration

2011 ◽  
Author(s):  
Shinichi Nishino ◽  
Mitsuaki Ochi ◽  
Kenji Kofu
Keyword(s):  
Influenza Virus ◽  
Acoustic Wave ◽  
Pressure Distribution ◽  
Standing Wave ◽  
Ultrasonic Vibration ◽  
Particle Motion ◽  
Acoustic Pressure ◽  
The Other ◽  
Calculation Domain ◽  
Plate Velocity

Particles on the plate vibrated by ultrasonic were gathered on the node of vibration plate. Similar to this phenomenon, if two plates are set with parallel, a plate is vibrated by ultrasonic and acoustic pressure distribution is produced between the vibration and reflection plate, nano-sized particles might be collected from the air flow and air is cleaned. Although ultrasonic was applied for the liquid and remove particles, but this has not been researched for air. Then the purpose of this study is to calculate the acoustic pressure distribution between the vibration and reflection plate by using CFD, and investigate the nano-sized particle motion in acoustic pressure distribution. When standing wave between plates is calculated, acoustic wave generated by ultrasonic vibration was reflected at the reflection plate. In the case of CFD, standing wave could not be calculated because these waves disclaim each other and wave generated by a plate doesn’t reach at the other plate. Therefore acoustic wave is also produced at reflection plate, duplicate these waves from vibration and reflection plates, and standing wave between plates were obtained. About investigation for the nano-sized particle motion in acoustic pressure distribution, particles were injected into calculation domain. Particles which have the same diameter and density with influenza virus were applied in this calculation. Examination of particle’s motion and efficient condition on dust catch were calculated in case of changing parameter, for example, amplitude and frequency of vibration plate, velocity of flowing particles, concentration of particles in the flow and so on.

scholarly journals Effects of Central Tube on Shape of Modal Duct of a Helicoid in a Simple Expansion Chamber

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Daniel Omondi Onyango ◽  
Robert Kinyua ◽  
Abel Nyakundi Mayaka
Keyword(s):  
Wave Propagation ◽  
Acoustic Wave ◽  
Plane Wave ◽  
Acoustic Pressure ◽  
Three Dimensional ◽  
The Other ◽  
Expansion Chamber ◽  
Central Tube ◽  
Simple Expansion ◽  
Plane Wave Propagation

The shape of the modal duct of an acoustic wave propagating in a muffling system varies with the internal geometry. This shape can be either as a result of plane wave propagation or three-dimensional wave propagation. These shapes depict the distribution of acoustic pressure that may be used in the design or modification of mufflers to create resonance at cut-off frequencies and hence achieve noise attenuation or special effects on the output of the noise. This research compares the shapes of acoustic duct modes of two sets of four pitch configurations of a helicoid in a simple expansion chamber with and without a central tube. Models are generated using Autodesk Inventor modeling software and imported into ANSYS 18.2, where a fluid volume from the complex computer-aided-design (CAD) geometry is extracted for three-dimensional (3D) analysis. Mesh is generated to capture the details of the fluid cavity for frequency range between 0 and 2000Hz. After defining acoustic properties, acoustic boundary conditions and loads were defined at inlet and outlet ports before computation. Postprocessed acoustic results of the modal shapes and transmission loss (TL) characteristics of the two configurations were obtained and compared for geometries of the same helical pitch. It was established that whereas plane wave propagation in a simple expansion chamber (SEC) resulted in a clearly defined acoustic pressure pattern across the propagation path, the distribution in the configurations with and without the central tube depicted three-dimensional acoustic wave propagation characteristics, with patterns scattering or consolidating to regions of either very low or very high acoustic pressure differentials. A difference of about 80 decibels between the highest and lowest acoustic pressure levels was observed for the modal duct of the geometry with four turns and with a central tube. On the other hand, the shape of the TL curve shifts from a sinusoidal-shaped profile with well-defined peaks and valleys in definite multiples of π for the simple expansion chamber, while that of the other two configurations depended on the variation in wavelength that affects the location of occurrence of cut-on or cut-off frequency. The geometry with four turns and a central tube had a maximum value of TL of about 90 decibels at approximately 1900Hz.

Simulation of a Layered Resonator for a Microfluidic Ultrasonic Separator

2006 ◽  
Author(s):  
Yijun Shen ◽  
Mark A. Atherton
Keyword(s):  
Energy Density ◽  
Pressure Distribution ◽  
Standing Wave ◽  
Acoustic Pressure ◽  
Separation Performance ◽  
Experimental Measurements ◽  
Driving Frequency ◽  
Stored Energy ◽  
Acoustic Characteristics ◽  
Small Spherical Particle

This paper focuses on the simulation of a layered resonator for a microfluidic ultrasonic separator with a special emphasis on analysing the stored energy-frequency product in the microfluid chamber. Since the acoustic force acting on a small spherical particle in a standing wave in the cavity of an ultrasonic separator is proportional to the product of the energy density in the standing wave and the driving frequency, the energy-frequency product can be used as a prediction of the separation performance in an ultrasonic separator. The electro-acoustic characteristics of the resonator under different conditions are also investigated. In particular, the influence of the reflector thickness on the stored energy-frequency product of the layered resonator is examined. Furthermore, the acoustic pressure distribution in the fluid chamber of the ultrasonic separator is investigated in detail. Predicted results from simulations compare well with experimental measurements and show that the model can be used to predict the electro-acoustic characteristics and the separation performance.

scholarly journals Experimental and numerical study of acoustic pressure distribution in a sonochemical reactor

2021 ◽  
Vol 1809 (1) ◽  
pp. 012025
Author(s):  
M O Kuchinskiy ◽  
T P Lyubimova ◽  
K A Rybkin ◽  
O O Fattalov ◽  
L S Klimenko
Keyword(s):  
Pressure Distribution ◽  
Acoustic Pressure ◽  
Numerical Study

The Numerical Analysis of the Velocity and Pressure Distribution of the Oil Film in Heavy Hydrostatic Thrust Bearing

2014 ◽  
Vol 541-542 ◽  
pp. 658-662
Author(s):  
Jian Li ◽  
Yuan Chen ◽  
Yang Chun Yu ◽  
Zhu Xin Tian ◽  
Yu Huang
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Pressure Distribution ◽  
Working Conditions ◽  
Thrust Bearing ◽  
Rotation Speed ◽  
The Other ◽  
Surface Load ◽  
Oil Film ◽  
Volume Method

To study the velocity and pressure distribution of the oil film in a heavy hydrostatic thrust bearing, a mathematical model of the velocity is proposed and the finite volume method (FVM) has been used to simulate the flow field under different working conditions. Some pressure experiments were carried out and the results verified the correctness of the simulation. It is concluded that the pressure distribution varies small under different rotation speed when the surface load on the workbench is constant. But the velocity of the oil film is influenced greatly by the rotation speed. When the rotation speed of the workbench is as quick as enough, the velocity of the oil film on one radial side of the pad will be zero, that is to say the lubrication oil will be drained from the other three sides of the recess.

scholarly journals HLA restriction of human cytotoxic T lymphocytes specific for influenza virus. Poor recognition of virus associated with HLA A2.

1978 ◽  
Vol 148 (6) ◽  
pp. 1458-1467 ◽  
Author(s):  
A McMichael
Keyword(s):  
Influenza Virus ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Influenza A ◽  
Human Peripheral Blood ◽  
Peripheral Blood Lymphocytes ◽  
The Other ◽  
Target Cells ◽  
Surface Molecules ◽  
Human Peripheral Blood Lymphocytes

Cytotoxic T lymphocytes (CTL), specific for influenza A/X31 virus, were generated from human peripheral blood lymphocytes. These CTL lysed target cells that were infected with the same virus and that shared HLA A or B locus antigens. Minimal lysis was observed when HLA-D antigens were shared. Not all HLA A and B antigens were equally effective. Efficient lysis of target cells was seen when HLA A1, A3, B7, B8, B27 and BW21 were shared with the CTL, but when HLA A2 was the only shared antigen lysis was usually minimal. This deficiency in CTL function associated with HLA A2 was not absolute. It is suggested that the function of this antigen might be influenced by other surface molecules on the cell and in particular the other HLA products.

scholarly journals Acoustophoretic Control of Microparticle Transport Using Dual-Wavelength Surface Acoustic Wave Devices

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 52 ◽  
Author(s):  
Jin-Chen Hsu ◽  
Chih-Hsun Hsu ◽  
Yeo-Wei Huang
Keyword(s):  
Particle Motion ◽  
Acoustic Waves ◽  
Acoustic Pressure ◽  
Acoustic Radiation ◽  
Surface Acoustic Waves ◽  
Microfluidic Channel ◽  
Radiation Force ◽  
Dual Wavelength ◽  
Single Frequency ◽  
Motion Trajectories

We present a numerical and experimental study of acoustophoretic manipulation in a microfluidic channel using dual-wavelength standing surface acoustic waves (SSAWs) to transport microparticles into different outlets. The SSAW fields were excited by interdigital transducers (IDTs) composed of two different pitches connected in parallel and series on a lithium niobate substrate such that it yielded spatially superimposed and separated dual-wavelength SSAWs, respectively. SSAWs of a singltablee target wavelength can be efficiently excited by giving an RF voltage of frequency determined by the ratio of the velocity of the SAW to the target IDT pitch (i.e., f = cSAW/p). However, the two-pitch IDTs with similar pitches excite, less efficiently, non-target SSAWs with the wavelength associated with the non-target pitch in addition to target SSAWs by giving the target single-frequency RF voltage. As a result, dual-wavelength SSAWs can be formed. Simulated results revealed variations of acoustic pressure fields induced by the dual-wavelength SSAWs and corresponding influences on the particle motion. The acoustic radiation force in the acoustic pressure field was calculated to pinpoint zero-force positions and simulate particle motion trajectories. Then, dual-wavelength SSAW acoustofluidic devices were fabricated in accordance with the simulation results to experimentally demonstrate switching of SSAW fields as a means of transporting particles. The effects of non-target SSAWs on pre-actuating particles were predicted and observed. The study provides the design considerations needed for the fabrication of acoustofluidic devices with IDT-excited multi-wavelength SSAWs for acoustophoresis of microparticles.

scholarly journals Moffatt-type flows in a trihedral cone

2013 ◽  
Vol 725 ◽  
pp. 446-461 ◽  
Author(s):  
Julian F. Scott
Keyword(s):  
Linear Combination ◽  
Particle Motion ◽  
Particle Trajectory ◽  
Three Dimensional ◽  
Parameter Family ◽  
The Other ◽  
Transient Phase ◽  
Primary Flow ◽  
Special Cases ◽  
Two Parameter

AbstractThe three-dimensional analogue of Moffatt eddies is derived for a corner formed by the intersection of three orthogonal planes. The complex exponents of the first few modes are determined and the flows resulting from the primary modes (those which decay least rapidly as the apex is approached and, hence, should dominate the near-apex flow) examined in detail. There are two independent primary modes, one symmetric, the other antisymmetric, with respect to reflection in one of the symmetry planes of the cone. Any linear combination of these modes yields a possible primary flow. Thus, there is not one, but a two-parameter family of such flows. The particle-trajectory equations are integrated numerically to determine the streamlines of primary flows. Three special cases in which the flow is antisymmetric under reflection lead to closed streamlines. However, for all other cases, the streamlines are not closed and quasi-periodic limiting trajectories are approached when the trajectory equations are integrated either forwards or backwards in time. A generic streamline follows the backward-time trajectory in from infinity, undergoes a transient phase in which particle motion is no longer quasi-periodic, before being thrown back out to infinity along the forward-time trajectory.

scholarly journals Haemagglutination-inhibiting (HI) antibodies against four prototype strains of influenza A virus in different age groups

1979 ◽  
Vol 82 (2) ◽  
pp. 225-230 ◽  
Author(s):  
A. L. Terzin ◽  
S. Djurišić ◽  
B. Vuković ◽  
V. Vujkov
Keyword(s):  
Influenza Virus ◽  
Hong Kong ◽  
New Jersey ◽  
Antibody Response ◽  
Influenza A ◽  
Geometric Mean ◽  
Age Groups ◽  
The Other ◽  
Younger Age ◽  
Lower Antibody Response

SUMMARYSera of 197 apparently well persons were tested for residual haemagglutination-inhibiting antibodies against live Hong Kong/68, A/FM/47 and A/PR/34 strains. Sera of 62 well persons, regularly exposed to contacts with swine, were tested against an inactivated A/New Jersey/76 antigen.Those born some time before and during a certain influenza era showed a significantly greater proportion of homologous residual titres against the subtype prevailing in that influenza era, than those born after the termination of the same era.In each of the seven age groups tested both the percentage of positives and the geometric mean titres were usually highest against the Hong Kong strain (representing the most recent era); the next highest were those against the FM1 strain and the lowest were those against the PR8 strain (representing the most distant of these three influenza eras).The serological involvement of donors exposed to regular contacts with swine was relatively stronger against the New Jersey antigen than the response of other serum donors shown against the other three, more recent, prototypes of influenza virus A. The oldest age groups showed significantly lower antibody response against the PR8, FM1 and Hong Kong strains (but not against the New Jersey antigen) than the next one or two of the younger age groups.

scholarly journals Effects of Hydrostatic Pocket Shape on the Flow Pattern and Pressure Distribution

1995 ◽  
Vol 1 (3-4) ◽  
pp. 225-235 ◽  
Author(s):  
M. J. Braun ◽  
M. Dzodzo
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Flow Pattern ◽  
Stokes Equations ◽  
The Other ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Hydrostatic Bearing ◽  
Collocated Grid ◽  
Dimensionless Formulation

The flow in a hydrostatic pocket is numerically simulated using a dimensionless formulation of the 2-D Navier-Stokes equations written in primitive variables, for a body fitted coordinates system, and applied through a collocated grid. In essence, we continue the work of Braun et al. 1993a, 1993b] and extend it to the study of the effects of the pocket geometric format on the flow pattern and pressure distribution. The model includes the coupling between the pocket flow and a finite length feedline flow, on one hand, and the pocket and its adjacent lands on the other hand. In this context we shall present, on a comparative basis, the flow and the pressure patterns at the runner surface for square, ramped-Rayleigh step, and arc of circle pockets. Geometrically all pockets have the same footprint, same lands length, and same capillary feedline. The numerical simulation uses the Reynolds number based on the lid(runner) velocity and the inlet jet strengthFas the dynamic similarity parameters. The study aims at establishing criteria for the optimization of the pocket geometry in the larger context of the performance of a hydrostatic bearing.

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