Investigation of Gas Detonation in Over-Rich Mixtures of Hydrocarbons with Oxygen

2018 ◽  
Keyword(s):  
Gas Detonation ◽  
Rich Mixtures

Investigation of Gas Detonation in Over-Rich Mixtures of Hydrocarbons with Oxygen

2018 ◽  
Vol 54 (2) ◽  
pp. 207-215 ◽  
Author(s):  
I. S. Batraev ◽  
A. A. Vasil’ev ◽  
V. Yu. Ul’yanitskii ◽  
A. A. Shtertser ◽  
D. K. Rybin
Keyword(s):  
Gas Detonation ◽  
Rich Mixtures

Gas-Detonation Mills

2006 ◽  
Vol 2 (3) ◽  
pp. 111-113
Author(s):  
A. Ye. Voytenko ◽  
Keyword(s):  
Gas Detonation

Gas-detonation processing of particles

2008 ◽  
Vol 46 (5) ◽  
pp. 686-694 ◽  
Author(s):  
V. A. Sychevskii
Keyword(s):  
Gas Detonation

Modeling of Hydrogen-Air Detonations in the TONUS CFD Code and Its Application to the FLAME F-19 Test

2008 ◽  
Author(s):  
Eveliina Takasuo
Keyword(s):  
Cfd Simulation ◽  
Hydrogen Combustion ◽  
Severe Accident ◽  
Parameter Study ◽  
Model Parameters ◽  
Gas Detonation ◽  
Global Rate ◽  
Detonation Structure ◽  
Mesh Resolution ◽  
Post Shock

In severe accident management, the ability to predict pressure and thermal loads resulting from hydrogen combustion is important since they may threaten containment integrity. In computational modeling, different combustion regimes have to be accounted for and state-of-the-art techniques developed for reliable analysis. In the present study, the focus is on computational fluid dynamics code validation for reactive flows in the detonation regime. The FLAME hydrogen combustion test F-19 performed at the Sandia National Laboratories has been simulated by using the gas detonation model implemented in the TONUS CFD code which is developed by CEA and IRSN (France). In this model the reactive Euler equations are solved and the reaction rate is obtained by the Arrhenius global rate equation. Several simulations were run in order to examine the effect of modifying the parameters of the chemistry model. A mesh convergence study was performed for the purpose of finding out the necessary mesh resolution which could capture the detonation propagation with adequate accuracy. In addition, Chapman-Jouguet post-shock equilibrium conditions and the ZND detonation structure for the present gas mixture were examined by chemical kinetics calculations. The CFD simulation results were compared to the test results and the Chapman-Jouguet post-shock conditions. It was observed that the computational results differ from the C-J results with the C-J velocity being slightly exceeded. The model parameter study showed that it is not possible to significantly affect the flame propagation by adjusting the model parameters.

scholarly journals Melting Point of Carbon Particles behind the Gas Detonation Front

2022 ◽  
Vol 16 (2) ◽  
pp. 59-70
Author(s):  
E. S. Prokhorov
Keyword(s):  
Melting Point ◽  
Detonation Front ◽  
Molar Fraction ◽  
Experimental Studies ◽  
Oxygen Mixture ◽  
Detonation Products ◽  
Gas Detonation ◽  
Nanoscale Particles ◽  
Carbon Particles ◽  
Carbon Condensate

A mathematical model of gas detonation of fuel-enriched mixtures of hydrocarbons with oxygen has been formulated, which makes it possible to numerically study the equilibrium flows of detonation products in the presence of free carbon condensation. Reference data for graphite were used to describe the thermodynamic properties of carbon condensate. The calculations are compared with the known results of experimental studies in which, when detonating an acetylene-oxygen mixture in a pipe closed at one end, it is possible to obtain nanoscale particles from a carbon material with special properties. It is assumed that the melting point of such a material is lower than that of graphite and is about 3100 K. Only with such an adjustment of the melting temperature, the best agreement (with an accuracy of about 3 %) was obtained between the calculated and experimental dependence of the detonation front velocity on the molar fraction of acetylene in the mixture.

scholarly journals Influence of gas detonation spraying parameters on the geometrical structure of Fe-Al intermetallic protective coatings

2019 ◽  
Author(s):  
Tomasz Chrostek ◽  
Mirosław Bramowicz ◽  
Kazimierz Rychlik ◽  
Wojtkowiak Adam ◽  
Cezary Senderowski
Keyword(s):  
Fractal Dimension ◽  
Geometric Structure ◽  
Geometrical Structure ◽  
Protective Coatings ◽  
Sampling Rate ◽  
Roughness Parameter ◽  
Powder Injection ◽  
Science Center ◽  
Detonation Spraying ◽  
Gas Detonation

The paper presents the results of an investigation and analysis of the geometrical structure of Fe-Al intermetallic protective coatings sprayed under specified gun detonation spraying (GDS) conditions. As GDS variable parameters there were applied two different barrel lengths and two powder injection position (PIP) at the moment of spark detonation as well as two different number of GDS shots with 6.66 Hz frequency. The measurements of the surface's profile were carried out through means of contact profilometry, in which case TOPO-01 system and Mitutoyo SJ 210 profilometer were applied. On the basis of the measurements conducted the analysis of in two-dimensional (2D) and spatial (3D) systems was made possible. The authors assumed that roughness can be considered as a non-stationary parameter of variance of surface amplitude, which is highly dependent on the sampling rate and length of an elementary segments. Therefore, the changes in the amplitude parameters and functional properties of the surface at different lengths of measuring segments (ln), respectively: 1.25, 4 and 12.5 mm, were analyzed. In the analysis of the degree of development of the geometric structure of the surface, the RMS (Root Mean Square) fractal method was used, with an assessment of the geometric structure of the surface stretched over several size levels, taking into account the correlation between the roughness parameter Rq, the measuring length (ln) and the fractal dimension (D). The application of the RMS method with the determination of the fractal dimension (D) allowed for the characterization of the geometric structure of intermetallic Fe-Al protective coatings detonation sprayed under specific conditions of the GDS process - based on the surface roughness profiles of different measured length (ln). Research undertaken within the framework of project No. 2015/19 / B / ST8 / 02000 subsidized by the National Science Center of Poland.

scholarly journals Tribological wear of Fe-Al coatings applied by gas detonation spraying

2021 ◽  
Author(s):  
Tomasz Chrostek
Keyword(s):  
Dry Friction ◽  
Shear Stresses ◽  
X Ray Diffraction ◽  
Detonation Spraying ◽  
Gas Detonation ◽  
Compressive Stresses ◽  
Spraying Parameters ◽  
Thin Oxide Films ◽  
Pin On Disc ◽  
The Coefficient Of Friction

Comparative tests of gas detonation (GDS) coatings were carried out in order to investigate the influence of spraying parameters on abrasive wear under dry friction conditions. The tests were carried out using the pin-on-disc (PoD) method at room temperature. The microstructure of the coatings was analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM / EDS) methods. The results showed that with specific GDS process parameters, the main phases in both coatings were FeAl and Fe3Al involving thin oxide films Al2O3. The tribological tests proved that the coatings sprayed with the shorter barrel of the GDS gun showed higher wear resistance. The coefficient of friction was slightly lower in the case of coatings sprayed with the longer barrel of the GDS gun. During dry friction, oxide layers form on the surface, which act as a solid lubricant. The load applied to the samples during the tests causes shear stresses, thus increasing the wear of the coatings. During friction, the surface of the coatings is subjected to alternating tensile and compressive stresses, which lead to delamination and is the main wear mechanism of the coatings.

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