On numerical modelling of gas flows through axisymmetric porous object with heterogeneous combustion sources under forced filtration

Using numerical experiment one-dimensional unsteady processes of heterogeneous combustion in porous object under free convection in horizontal case have been investigated and compared with vertical case. It is shown that in the case of the horizontal porous object the oxidizer supply, which is the result of natural convection, is not sufficient for the appearance of stable wave of heterogeneous combustion. In contrast to the vertical position of the object, there are no long-lived combustion waves in the horizontal case, which completely burns down the solid combustible material. When the ignition zone is on the border of the object, the combustion wave near the vicinity of the boundary burns the oxygen and becomes extinct. When the ignition zone is in the center of the porous object, two combustion waves arise which may move very slowly, burn oxygen and become extinct.

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Numerical Comparison of Gas Flows through Plane Porous Heat-Evolutional Object with Axisymmetric one when Object's Outlet is Partially Closed

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1040.529 ◽

2014 ◽

Vol 1040 ◽

pp. 529-534

Author(s):

Nickolay A. Lutsenko

Keyword(s):

Numerical Experiment ◽

Uniform Distribution ◽

Gas Flow ◽

Computational Experiment ◽

Gas Flows ◽

Numerical Comparison ◽

Heat Sources ◽

Cooling Process ◽

Partial Closure ◽

Porous Object

Using numerical experiment the gas flow in the gravity field through a plane porous object with heat sources inside and partial closure of the object's outlet has been investigated and compared with axisymmetric case. The influence of partial closure of the object's outlet on the cooling process of the plane porous objects with a non-uniform distribution of heat sources has been analyzed by means of computational experiment. It has been revealed that effect of the top cover on a cooling process of the plane porous objects is qualitatively the same as in the axisymmetric objects, but quantitative differences are significant.

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Numerical Method for Investigation of 1D Processes in Porous Media with Heterogeneous Reactions when Flow Rate of Oxidant Regulates itself

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.880.115 ◽

2014 ◽

Vol 880 ◽

pp. 115-120 ◽

Cited By ~ 10

Author(s):

Nickolay A. Lutsenko ◽

Svetana N. Sorokova

Keyword(s):

Porous Media ◽

Numerical Method ◽

Flow Rate ◽

Filtration Combustion ◽

Heterogeneous Reactions ◽

Finite Difference Schemes ◽

Gas Flows ◽

Gas Filtration ◽

Implicit Finite Difference ◽

Porous Object

The time-dependent gas flows through porous objects with heterogeneous reactions are considered when the gas pressure at object boundaries is known but the flow rate and velocity of the gas filtration at the inlet to the porous objects are unknown. In such porous objects the flow rate of oxidant, which enters into the reaction zone in porous object, regulates itself. An original numerical method, based on a combination of explicit and implicit finite-difference schemes, have been developed for investigating the unsteady gas flows in such porous objects with zones of heterogeneous reactions. Used approach enables to solve problems of filtration combustion for both forced filtration and free convection, so it can be efficiently applied for modeling the combustion zones in porous media, which may arise from natural or man-caused disasters.

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In Situ Observation of Catalyzed Gasification of Graphite by Nickel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097090 ◽

1981 ◽

Vol 39 ◽

pp. 76-77

Author(s):

R. T. K. Baker ◽

R. D. Sherwood

Keyword(s):

Objective Lens ◽

In Situ Observation ◽

Gas Flows ◽

Catalytic Gasification ◽

Television Camera ◽

Viewing Screen ◽

Fuels And Chemicals ◽

Gasification Of Carbon ◽

Transmission Microscope

The catalytic gasification of carbon at high temperature by microscopic size metal particles is of fundamental importance to removal of coke deposits and conversion of refractory hydrocarbons into fuels and chemicals. The reaction of metal/carbon/gas systems can be observed by controlled atmosphere electron microscopy (CAEM) in an 100 KV conventional transmission microscope. In the JEOL gas reaction stage model AGl (Fig. 1) the specimen is positioned over a hole, 200μm diameter, in a platinum heater strip, and is interposed between two apertures, 75μm diameter. The control gas flows across the specimen and exits through these apertures into the specimen chamber. The gas is further confined by two apertures, one in the condenser and one in the objective lens pole pieces, and removed by an auxiliary vacuum pump. The reaction zone is <1 mm thick and is maintained at gas pressure up to 400 Torr and temperature up to 1300<C as measured by a Pt-Pt/Rh 13% thermocouple. Reaction events are observed and recorded on videotape by using a Philips phosphor-television camera located below a hole in the center of the viewing screen. The overall resolution is greater than 2.5 nm.

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