Discrete vortices in the wake of various profiles in subsonic and supersonic two-dimensional gas flow

1972 ◽  
Vol 3 (5) ◽  
pp. 113-118
Author(s):  
O. M. Kuznetsov ◽  
S. G. Popov
Keyword(s):  
Gas Flow ◽  
Two Dimensional

Deposition of particles in a two-dimensional lattice gas flow

1992 ◽  
Vol 68 (13) ◽  
pp. 2027-2030 ◽  
Author(s):  
Jean-Christophe Toussaint ◽  
Jean-Marc Debierre ◽  
Loïc Turban
Keyword(s):  
Gas Flow ◽  
Lattice Gas ◽  
Two Dimensional ◽  
Dimensional Lattice

TRIGGERING OF DETONATION PROCESSES IN PROPULSION CHAMBER

2021 ◽  
Vol 14 (2) ◽  
pp. 40-45
Author(s):  
D. V. VORONIN ◽  
Keyword(s):  
Thermal Conductivity ◽  
Numerical Modeling ◽  
Gas Flow ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Navier Stokes Equations ◽  
Chemically Reacting ◽  
Plane Disk ◽  
And Diffusion

The Navier-Stokes equations have been used for numerical modeling of chemically reacting gas flow in the propulsion chamber. The chamber represents an axially symmetrical plane disk. Fuel and oxidant were fed into the chamber separately at some angle to the inflow surface and not parallel one to another to ensure better mixing of species. The model is based on conservation laws of mass, momentum, and energy for nonsteady two-dimensional compressible gas flow in the case of axial symmetry. The processes of viscosity, thermal conductivity, turbulence, and diffusion of species have been taken into account. The possibility of detonation mode of combustion of the mixture in the chamber was numerically demonstrated. The detonation triggering depends on the values of angles between fuel and oxidizer jets. This type of the propulsion chamber is effective because of the absence of stagnation zones and good mixing of species before burning.

Two-dimensional model of reactive gas flow in a diamond film CVD reactor

1995 ◽  
Vol 4 (8) ◽  
pp. 1065-1068 ◽  
Author(s):  
Y.A. Mankelevich ◽  
A.T. Rakhimov ◽  
N.V. Suetin
Keyword(s):  
Diamond Film ◽  
Gas Flow ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Dimensional Model ◽  
Reactive Gas

Steady small-disturbance transonic dense gas flow past two-dimensional compression/expansion ramps

2018 ◽  
Vol 848 ◽  
pp. 756-787 ◽  
Author(s):  
A. Kluwick ◽  
E. A. Cox
Keyword(s):  
Gas Dynamics ◽  
Gas Flow ◽  
External Forcing ◽  
Two Dimensional ◽  
Small Disturbance ◽  
Dense Gas ◽  
Dimensional Flow ◽  
Flow Past ◽  
Two Dimensional Flow ◽  
Dimensional Parameters

The behaviour of steady transonic dense gas flow is essentially governed by two non-dimensional parameters characterising the magnitude and sign of the fundamental derivative of gas dynamics ($\unicode[STIX]{x1D6E4}$) and its derivative with respect to the density at constant entropy ($\unicode[STIX]{x1D6EC}$) in the small-disturbance limit. The resulting response to external forcing is surprisingly rich and studied in detail for the canonical problem of two-dimensional flow past compression/expansion ramps.

scholarly journals Erosion of planetesimals by gas flow

2020 ◽  
Vol 639 ◽  
pp. A39 ◽  
Author(s):  
Noemi Schaffer ◽  
Anders Johansen ◽  
Lukas Cedenblad ◽  
Bernhard Mehling ◽  
Dhrubaditya Mitra
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Lattice Boltzmann ◽  
Critical Stress ◽  
Gas Flow ◽  
Protoplanetary Disks ◽  
Two Dimensional ◽  
Eccentric Orbit ◽  
Eccentric Orbits ◽  
Boltzmann Method

The first stages of planet formation take place in protoplanetary disks that are largely made up of gas. Understanding how the gas affects planetesimals in the protoplanetary disk is therefore essential. In this paper, we discuss whether or not gas flow can erode planetesimals. We estimated how much shear stress is exerted onto the planetesimal surface by the gas as a function of disk and planetesimal properties. To determine whether erosion can take place, we compared this with previous measurements of the critical stress that a pebble-pile planetesimal can withstand before erosion begins. If erosion took place, we estimated the erosion time of the affected planetesimals. We also illustrated our estimates with two-dimensional numerical simulations of flows around planetesimals using the lattice Boltzmann method. We find that the wall shear stress can overcome the critical stress of planetesimals in an eccentric orbit within the innermost regions of the disk. The high eccentricities needed to reach erosive stresses could be the result of shepherding by migrating planets. We also find that if a planetesimal erodes, it does so on short timescales. For planetesimals residing outside of 1 au, we find that they are mainly safe from erosion, even in the case of highly eccentric orbits.

Three-Dimensional Simulation of Gas Flow in Microducts

2005 ◽  
Author(s):  
Abhishek Agrawal ◽  
Amit Agrawal
Keyword(s):  
Aspect Ratio ◽  
Knudsen Number ◽  
Gas Flow ◽  
Flow Direction ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Streamwise Velocity ◽  
Theoretical Development ◽  
Width Ratio ◽  
Two Dimensional

Three-dimensional lattice Boltzmann method based simulations of a microduct have been undertaken in this paper. The objective is to understand the different physical phenomena occurring at these small scales and to investigate when the flow can be treated as two-dimensional. Towards this end, the Knudsen number and aspect ratio (depth to width ratio) are varied for a fixed pressure ratio. The pressure in the microduct is non-linear with the non-linearity in pressure reducing with an increase in Knudsen number. The pressure and velocity behaves somewhat similar to two-dimensional microchannels even when the aspect ratio is unity. The slip velocity at the impenetrable wall has two components: along and perpendicular to the flow. Our results show that the streamwise velocity near the centerline is relatively invariant along the depth for aspect ratio more than three, suggesting that the microduct can be modeled as a two-dimensional microchannel. However, the velocity component along the depth is never identically zero, implying that the flow is not truly two-dimensional. A curious change in vector direction in a plane normal to the flow direction is observed around aspect ratio of four. These first set of three-dimensional results are significant because they will help in theoretical development and flow modeling at micro scales.

scholarly journals Hydrodynamical simulations of the barred spiral galaxy NGC 1097

2012 ◽  
Vol 10 (H16) ◽  
pp. 376-376
Author(s):  
Lien-Hsuan Lin ◽  
Hsiang-Hsu Wang ◽  
Pei-Ying Hsieh ◽  
Ronald E. Taam ◽  
Chao-Chin Yang ◽  
...  
Keyword(s):  
Spiral Galaxy ◽  
Gas Flow ◽  
Elliptical Galaxy ◽  
The Self ◽  
Two Dimensional ◽  
Nuclear Ring ◽  
Barred Spiral Galaxy ◽  
Circumnuclear Disk ◽  
Hydrodynamical Simulations ◽  
Self Gravity

AbstractNGC 1097 is a nearby barred spiral galaxy believed to be interacting with the elliptical galaxy NGC 1097A located to its northwest. It hosts a Seyfert 1 nucleus surrounded by a circumnuclear starburst ring. Two straight dust lanes connected to the ring extend almost continuously out to the bar. The other ends of the dust lanes attach to two main spiral arms. To provide a physical understanding of its structural and kinematical properties, two-dimensional hydrodynamical simulations have been carried out. Numerical calculations reveal that many features of the gas morphology and kinematics can be reproduced provided that the gas flow is governed by a gravitational potential associated with a slowly rotating strong bar. By including the self-gravity of the gas disk in our calculation, we have found the starburst ring to be gravitationally unstable which is consistent with the observation in Hsieh et al. (2011). Our simulations also show that gas can flow into the region within the starburst ring even after its formation, leading to the coexistence of both a nuclear ring and a circumnuclear disk.

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