Dynamics of diffusion flames in a very low strain rate flow field: from transient one-dimensional to stationary two-dimensional regime

2021 ◽  
pp. 1-28
Author(s):  
Matheus P. Severino ◽  
Mariovane S. Donini ◽  
Fernando F. Fachini
Keyword(s):  
Flow Field ◽  
Strain Rate ◽  
Diffusion Flames ◽  
Two Dimensional ◽  
One Dimensional ◽  
Low Strain Rate

Effects of Heat Losses on Edge-flame Instabilities in Low Strain Rate Counterflow Diffusion Flames

2006 ◽  
Vol 30 (10) ◽  
pp. 996-1002
Author(s):  
June-Sung Park ◽  
Dong-Jin Hwang ◽  
Jeong-Soo Kim ◽  
Sang-In Keel ◽  
Tae-Kwon Kim ◽  
...  
Keyword(s):  
Strain Rate ◽  
Diffusion Flames ◽  
Heat Losses ◽  
Counterflow Diffusion Flames ◽  
Flame Instabilities ◽  
Low Strain Rate

Edge flame instability in low-strain-rate counterflow diffusion flames

2006 ◽  
Vol 146 (4) ◽  
pp. 612-619 ◽  
Author(s):  
J PARK ◽  
D HWANG ◽  
J PARK ◽  
J KIM ◽  
S KIM ◽  
...  
Keyword(s):  
Strain Rate ◽  
Diffusion Flames ◽  
Flame Instability ◽  
Counterflow Diffusion Flames ◽  
Low Strain Rate

A Simple Model for Fluid Flow and Particle Motion Inside the Human Larynx

Volume 4 ◽  
2004 ◽  
Author(s):  
C. Ersahin ◽  
I. B. Celik ◽  
O. C. Elci ◽  
I. Yavuz ◽  
J. Li ◽  
...  
Keyword(s):  
Flow Field ◽  
Particle Deposition ◽  
Flow Distribution ◽  
Axial Direction ◽  
Correction Method ◽  
Accurate Solution ◽  
Two Dimensional ◽  
Transient Model ◽  
One Dimensional ◽  
Dimensional Flow

This study aims to develop a simple and quick, but sufficiently accurate solution method for calculating the air flow and tracking the particles in a complex tubular system, where the flow changes its magnitude and direction in a periodic manner. The flow field is assumed to be quasi-two-dimensional and a pressure-correction method is employed to calculate the spetio-temporal variation of the air velocity inside the larynx. Then, the calculated one-dimensional flow distribution is used to reconstruct a two-dimensional flow field is constructed based on the average velocity along the axial direction. The system geometry is taken as close as possible to the actual larynx for an average person with an average glottis opening. For the current study the walls of the larynx is approximated as rigid walls, but different ways to account for compliant walls are proposed within the context of the one-dimensional mode. The 1-D transient model is validated against a two-dimensional model using a verified commercial code. Particles are introduced into the system and tracked during every time fraction of the respiratory cycle. Then, the histograms of particles that come into contact with the larynx are calculated, and regions with a higher probability for particle deposition are identified.

Numerical Simulation of Flow Field within Mutational Section Pipe

2012 ◽  
Vol 192 ◽  
pp. 190-195
Author(s):  
Jian Hua Zhang ◽  
Kun Hu ◽  
Yi Fan Xu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Pipe Flow ◽  
Gas Flow ◽  
Two Dimensional ◽  
One Dimensional ◽  
Compressed Gas ◽  
Interior Flow ◽  
Gas Flow Field

The section mutation of a pipe affects the interior flow field seriously. Numerical simulation of the two-dimensional steady gas flow field of two types of section mutation pipe was processed. By comparing it with equivalent section pipe’s interior flow field, the effects of section mutation of pipe on pressure distributing and velocity distributing were analyzed. The results are commendably consistent with the theories of one-dimensional adiabatic frictional pipe flow. Ensuring the section of the compressed gas pipe to be coherent and using the bell and spigot joint if necessary are presented.

The Simulation of Mixing Layers Driven by Compound Buoyancy and Shear

1996 ◽  
Vol 118 (2) ◽  
pp. 370-376 ◽  
Author(s):  
D. M. Snider ◽  
M. J. Andrews
Keyword(s):  
Growth Rate ◽  
Flow Field ◽  
Numerical Solution ◽  
Mixing Layer ◽  
Measured Data ◽  
Mixing Layers ◽  
Two Dimensional ◽  
One Dimensional ◽  
Self Similar ◽  
Accurate Numerical Solution

Fully developed compound shear and buoyancy driven mixing layers are predicted using a k-ε turbulence model. Such mixing layers present an exchange of equilibrium in mixing flows. The k-ε buoyancy constant Cε3 = 0.91, defined in this study for buoyancy unstable mixing layers, is based on an approximate self-similar analysis and an accurate numerical solution. One-dimensional transient and two-dimensional steady calculations are presented for buoyancy driven mixing in a uniform flow field. Two-dimensional steady calculations are presented for compound shear and buoyancy driven mixing. The computed results for buoyancy alone and compound shear and buoyancy mixing compare well with measured data. Adding shear to an unstable buoyancy mixing layer does not increase the mixing growth rate compared with that from buoyancy alone. The nonmechanistic k-ε model which balances energy generation and dissipation using constants from canonical shear and buoyancy studies predicts the suppression of the compound mixing width. Experimental observations suggest that a reduction in growth rate results from unequal stream velocities that skew and stretch the normally vertical buoyancy plumes producing a reduced mixing envelope width.

Success and shortcomings of clarifier modelling

1995 ◽  
Vol 31 (2) ◽  
pp. 181-191 ◽  
Author(s):  
Peter Krebs
Keyword(s):  
Flow Field ◽  
Boundary Conditions ◽  
Basic Knowledge ◽  
Future Research ◽  
Hydrodynamic Modelling ◽  
Two Dimensional ◽  
One Dimensional ◽  
Settling Behaviour ◽  
Dimensional Models

Various types of final clarifier model are introduced. The approaches and simplifications used for one-dimensional modelling are outlined, whilst new results of hydrodynamic modelling demonstrate how complex the flow field and the interactions with the settling behaviour of the sludge are. Based on the examination of which processes and boundary conditions affect the clarifier performance, what basic knowledge is lacking for modelling is analysed. One- and two-dimensional models are assessed with respect to their capacities and their shortcomings. Finally, the promising applications of the various models are pointed out, and future research potential for significant improvement of modelling is indicated.

scholarly journals Measurement of strain-rate components in a glacier with embedded inclinometers: numerical analysis

2013 ◽  
Vol 59 (215) ◽  
pp. 499-502 ◽  
Author(s):  
Mariam Jaber ◽  
Heinz Blatter ◽  
Marco Picasso
Keyword(s):  
Numerical Analysis ◽  
Flow Field ◽  
Strain Rate ◽  
Newtonian Fluid ◽  
Solid Body ◽  
Rotation Rate ◽  
Unit Vector ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Two Dimensional Flow

AbstractInclinometry with embedded probes is analyzed with a Stokes model of a solid body floating in a fluid with much smaller viscosity for a two-dimensional flow field. The assumption that such a probe behaves like a Lagrangian unit vector is only justified for probes embedded in a Newtonian fluid with lengths at least four times their width. A fluid with Glen-type rheology results in a slightly smaller rotation rate of the probe compared to Newtonian fluids.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

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