Current status of the high-temperature kinetic models of silane: Part II. Oxidation

Abstract

Abstract The present study is the second part of our work on the current status of high-temperature kinetic models of silane. Except Slakman’s model, all the models tested in the first part of the study, restricted to the pyrolysis dataset, are now compared against a large validation dataset (230 conditions) for silane oxidation. This large validation dataset is composed of both new and literature data, mainly representative of the highly-diluted and high-temperature oxidation of silane with different oxidizers ( O 2 , N 2 O , and NO) and diluents (Ar and N 2 ) over an extensive range of temperature ( T = [801– 2955 K]) and pressure ( P = [50 – 629 kPa]) conditions. The new experimental data are limited to SiH 4 - O 2 -Ar mixtures, obtained in a double-diaphragm shock tube equipped with an Atomic Resonance Absorption Spectroscopy (ARAS) detection technique. Experimental results present the temporal evolution of the total absorption signal, considering the absorption of O, Si, N 2 O , and SiH 4 . The performance of the models is assessed based on the same five validation criteria and objective function calculation, as presented in the first part of the study. The model of Chatelain and of Mevel present good performances with a global error of 2.4, i.e. meaning an average error of 2.4 fold above the experimental uncertainty, and high fraction (70 %) of criteria predicted within two times the experimental uncertainty. Although the reference reaction models performed better on the oxidation dataset compared to the pyrolysis dataset (part I), their global error is still 50 to 125 % higher than the two most accurate reaction models. Rate of production and sensitivity analyses revealed that the origin of the discrepancy of the least performing models can be attributed to the reaction pathways consuming/producing Si and O atoms and to some kinetic rates that must be updated.