Prediction of airway deformation effect on pulmonary air-particle dynamics: A numerical study

2021 ◽  
Vol 33 (10) ◽  
pp. 101906
Author(s):  
Jianan Zhao ◽  
Yu Feng ◽  
Kenichiro Koshiyama ◽  
Huimin Wu
Keyword(s):  
Numerical Study ◽  
Particle Dynamics ◽  
Deformation Effect

scholarly journals WAKEFIELDS AND DRIVE ELECTRON BUNCHES DYNAMICS IN THREE-ZONE DIELECTRIC RESONATOR AT ASYMMETRICAL INJECTION

2019 ◽  
pp. 58-62
Author(s):  
K.V. Galaydych ◽  
R.R. Kniaziev ◽  
G.A. Krivonosov ◽  
I.N. Onishchenko ◽  
G.V. Sotnikov
Keyword(s):  
Spatial Distribution ◽  
Relativistic Electron ◽  
Dielectric Resonator ◽  
Numerical Study ◽  
Particle Dynamics ◽  
Axial Injection ◽  
Electron Bunches

A numerical study of the wakefield excitation in a rectangular dielectric-loaded resonator by a sequence of relativistic electron bunches in the case of non-axial injection is carried out. The effect of the shift of injected bunches on the particle dynamics, as well as on the spatial distribution of the components of the bunch-excited fields, is studied. The current losses of a sequence of relativistic electron bunches due to the particles deposition on the surface of the dielectric is determined.

Nonlinear particle dynamics in a broadband turbulence wave spectrum

1998 ◽  
Vol 60 (2) ◽  
pp. 299-329 ◽  
Author(s):  
BRIGITTE R. RAGOT
Keyword(s):  
Correlation Time ◽  
Numerical Study ◽  
Wave Spectrum ◽  
Particle Interaction ◽  
Spectral Width ◽  
Particle Dynamics ◽  
Point Of View ◽  
Quasilinear Theory ◽  
Wave Particle Interaction ◽  
Velocity Variance

In the statistical quasilinear theory of weak plasma turbulence, charged particles moving in electrostatic fluctuations diffuse in velocity, i.e. the velocity variance 〈Δv2(t)〉 increases linearly with time t, for times long compared with the auto-correlation time τac of the field, which may be estimated as the reciprocal of the spectral width of the fluctuations. Recent test-particle simulations have revealed a new regime at very long timescales t[Gt ]τac where quasilinear theory breaks down, for intermediate field amplitudes. As this behaviour is not consistent with a diffusion on quasilinear timescales, the problem of the motion of particles in a broadband wave field, for the case of a slowly growing field, is considered here from a purely dynamical point of view, introducing no statistics on the field and no restriction on the amplitude of this field. By determining, on a given timescale, and in the frame of wave–particle interaction, the spectral width over which waves interact efficiently with a particle, a new timescale is found: the nonlinear time of wave–particle interaction τNL∝ (spectral density of energy)−1/3[Gt ]τac. This is the correlation time of the dynamics. For times shorter than τNL, the particles trajectories remain globally regular, and do not separate: they follow a quasifractal set of dimension 2. For times long compared with τNL, there appears a ‘true’ diffusive regime with mixing and decorrelation, due to nonlinear mixing in phase space and the localization of the wave–particle interaction. These theoretical results are confirmed by a numerical study of the velocity variance as a function of time. In particular, the particle dynamics really do become diffusive on timescales several orders of magnitude longer than that predicted by quasilinear theory (namely [Gt ]τNL[Gt ]τac). Finally, deviations from the quasilinear value of the diffusion coefficient and wave growth rate, discussed in the literature, are explained.

scholarly journals Numerical study of the dust-air current around the spherical suction unit screened by the circular swirling jet. Part 2. The dust particle dynamics

2018 ◽  
pp. 74-77
Author(s):  
M. S. Gritskevich ◽  
K. I. Logachev ◽  
O. A. Averkova ◽  
V. A. Tkachenko
Keyword(s):  
Dust Particle ◽  
Numerical Study ◽  
Air Flow ◽  
Particle Dynamics ◽  
Closed Space ◽  
Particle Behavior ◽  
Swirling Jet

The method is regarded for the pollutions screening with using the local suction hood. The investigating results are given for the particle behavior in the air flow nearby the local suction unit screened by means of the circular swirling jet, located both over the impermeable surface and in the closed space inside the aspiration hood.Ill.11.

Numerical Study to Examine the Effect of Porosity on In-Flight Particle Dynamics

2011 ◽  
Vol 20 (3) ◽  
pp. 630-637 ◽  
Author(s):  
S. Kamnis ◽  
S. Gu ◽  
M. Vardavoulias
Keyword(s):  
Numerical Study ◽  
Particle Dynamics

Numerical Study on the Diffusive-Ballistic Heat Transport in a Two-Dimensional Square Plate

2013 ◽  
Author(s):  
Toru Yamada ◽  
Keunhan Park ◽  
Yutaka Asako ◽  
Mohammad Faghri ◽  
Bengt Sundén
Keyword(s):  
Numerical Study ◽  
Dissipative Particle Dynamics ◽  
Boltzmann Transport Equation ◽  
Particle Dynamics ◽  
Two Dimensional ◽  
Boltzmann Transport ◽  
Solution Domain ◽  
Relaxation Time Approximation ◽  
Energy Conserving ◽  
Square Plate

The heat conduction in a two-dimensional square plate at nano/micro scales is investigated using numerical and semi-analytical methodologies which are energy conserving dissipative particle dynamics (DPDe) and Boltzmann transport equation (BTE) with the gray relaxation time approximation. The solution domain was considered to be a two-dimensional square plate surrounded by walls having constant temperatures. The numerical and semi-analytical results for different Knudsen numbers ranging from 0.1 to 10 are presented in form of temperature distributions in the solution domain. These results are compared with each other and the applicability of the DPDe model to two-dimensional structures is discussed.

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