scholarly journals Development and Parametric Evaluation of a Tabulated Chemistry Tool for the Simulation of n-Heptane Low-Temperature Oxidation and Autoignition Phenomena

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
George Vourliotakis ◽  
Dionysios I. Kolaitis ◽  
Maria A. Founti
Keyword(s):  
Low Temperature ◽  
Residence Time ◽  
Diesel Oil ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Cool Flame ◽  
Fuel Concentration ◽  
Tabulated Chemistry ◽  
The Impact ◽  
Independent Parameters

Accurate modelling of preignition chemical phenomena requires a detailed description of the respective low-temperature oxidative reactions. Motivated by the need to simulate a diesel oil spray evaporation device operating in the “stabilized” cool flame regime, a “tabulated chemistry” tool is formulated and evaluated. The tool is constructed by performing a large number of kinetic simulations, using the perfectly stirred reactor assumption. n-Heptane is used as a surrogate fuel for diesel oil and a detailed n-heptane mechanism is utilized. Three independent parameters (temperature, fuel concentration, and residence time) are used, spanning both the low-temperature oxidation and the autoignition regimes. Simulation results for heat release rates, fuel consumption and stable or intermediate species production are used to assess the impact of the independent parameters on the system’s thermochemical behaviour. Results provide the physical and chemical insight needed to evaluate the performance of the tool when incorporated in a CFD code. Multidimensional thermochemical behaviour “maps” are created, demonstrating that cool flame activity is favoured under fuel-rich conditions and that cool flame temperature boundaries are extended with increasing fuel concentration or residence time.

Low-temperature oxidation and cool flames of propane

1954 ◽  
Vol 221 (1145) ◽  
pp. 151-170 ◽  
Keyword(s):  
Low Temperature ◽  
Thermal Instability ◽  
Analytical Study ◽  
Simple Explanation ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Cool Flame ◽  
Cool Flames ◽  
Oxidation Of Hydrocarbons ◽  
Flame Oxidation

A detailed analytical study of the cool-flame oxidation of propane has been carried out using a continuous-flow technique with a view to the further elucidation of the mechanism of the low-temperature oxidation of hydrocarbons. The formation of the three theoretically possible aldehydes has been demonstrated and the initially formed peroxide shown to be hydrogen peroxide. Measurements of the yields of the different products formed under varying conditions of temperature, composition and time of contact have been made and correlated with measurements of the luminous intensity and temperature of the flame. The results confirm the earlier conclusions of Norrish (1948) that aldehydes are the important branching agents in the temperature range of 300 to 400°C, and a detailed scheme based on that proposed earlier has been developed to account for the observations. The scheme has further been shown to allow of a simple explanation of the origin of the periodic character of the cool flame in terms of the thermal instability of the normal slow reaction.

LOW-TEMPERATURE OXIDATION OF A LIQUID FUEL DROPLET IN MICROGRAVITY CONDITIONS

2020 ◽  
Author(s):  
F. S. FROLOV ◽  
◽  
V. Ya. BASEVICH ◽  
S. M. FROLOV ◽  
◽  
...  
Keyword(s):  
Low Temperature ◽  
Liquid Fuel ◽  
Scientific Data ◽  
Space Experiment ◽  
Fuel Droplet ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Cool Flame ◽  
Microgravity Conditions

During American-Russian space experiment CFI (Cool Flame Investigation) - Zarevo, new and very valuable scientific data on the differences in the burning of liquid fuel drops on the ground and in microgravity were obtained.

scholarly journals Influence of Co-Precipitation Agent on the Structure, Texture and Catalytic Activity of Au-CeO2 Catalysts in Low-Temperature Oxidation of Benzyl Alcohol

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 641
Author(s):  
Lukasz Wolski ◽  
Grzegorz Nowaczyk ◽  
Stefan Jurga ◽  
Maria Ziolek
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Low Temperature ◽  
Benzyl Alcohol ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Oxidation Of Benzyl Alcohol ◽  
Key Factor ◽  
Au Particle Size ◽  
Co Precipitation

The aim of the study was to establish the influence of a co-precipitation agent (i.e., NaOH–immediate precipitation; hexamethylenetetramine/urea–gradual precipitation and growth of nanostructures) on the properties and catalytic activity of as-synthesized Au-CeO2 nanocomposites. All catalysts were fully characterized with the use of XRD, nitrogen physisorption, ICP-OES, SEM, HR-TEM, UV-vis, XPS, and tested in low-temperature oxidation of benzyl alcohol as a model oxidation reaction. The results obtained in this study indicated that the type of co-precipitation agent has a significant impact on the growth of gold species. Immediate co-precipitation of Au-CeO2 nanostructures with the use of NaOH allowed obtainment of considerably smaller and more homogeneous in size gold nanoparticles than those formed by gradual co-precipitation and growth of Au-CeO2 nanostructures in the presence of hexamethylenetetramine or urea. In the catalytic tests, it was established that the key factor promoting high activity in low-temperature oxidation of benzyl alcohol was size of gold nanoparticles. The highest conversion of the alcohol was observed for the catalyst containing the smallest Au particle size (i.e., Au-CeO2 nanocomposite prepared with the use of NaOH as a co-precipitation agent).

Low temperature oxidation of copper alloys—AEM and AFM characterization

2007 ◽  
Vol 42 (12) ◽  
pp. 4684-4691 ◽  
Author(s):  
Mari Honkanen ◽  
Minnamari Vippola ◽  
Toivo Lepistö
Keyword(s):  
Low Temperature ◽  
Copper Alloys ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation
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