English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A systematic survey of chemical kinetic mechanisms (both simplified and global) shows an absence of a robust kinetic mechanism that can accurately predict characteristics of syngas-air nonpremixed flames. In this work, a three-step global kinetics mechanism is proposed for predicting the extinction strain rate ( a g) of syngas-air nonpremixed flames. The available experimental  a gdata-set from the Tsuji type burner was used to evaluate the performance of six syngas kinetics models (four simplified and two global). For this, 2D-planar computations were performed to obtain  a gvalues using four CO/H 2  ratios (1, 3, 5, and 29). The results showed that all the simplified kinetics mechanisms overpredicted the  a gvalues in the range of 16–224% for the four CO/H 2  ratios. In the case of the global kinetics models namely, CFFR and WO, except for CO/H 2  ratio of 29, CFFR underpredicted  a gvalues by 22–55%. WO underpredicted  a gby 10–44% for CO/H 2  = 1 and overpredicted  a gby 19–58% for CO/H 2  = 3 and 5. For CO/H 2  = 29, WO overpredicted  a gvalues by 151–205%. For CO/H 2  = 1, WO underpredicted  a gdue to two reasons, (1) double accounting of CO hydroxyl oxidation path and, (2) suppression of H 2  oxidation pathways in four-step global JL mechanism, a source for the construction of WO mechanism. From the overall perceptive, WO has performed better compared to other mechanisms. Hence, WO was chosen for further optimization using experimental  a gdata as a target. Sensitivity analysis in terms of  a gand maximum flame temperature ( T F) was performed for WO using two CO/H 2  ratios (1 and 5). It was found that for CO/H 2  = 1 and 5,  a gis most sensitive to Rxn1 (H 2  + 0.5O 2 ↔ H 2 O) and Rxn2 (CO + 0.5O 2  → CO 2 ). Results from sensitivity analysis, 0D (PSR) computations, and 2D computations have shown that the improper quantification of CO and H 2  oxidation pathways leads to inaccurate  a gprediction by the WO model. Based on these new insights, a modified three-step WO syngas kinetics model (WO-Opt) is proposed for predicting the extinction strain rate of syngas-air nonpremixed flames. The WO-Opt model was validated against  a gexperimental data. Compared to the WO model,  a gpredictions obtained from the modified WO-Opt model were in good agreement with the syngas-air nonpremixed flames experiments.

A Three-step Global Kinetic Mechanism for Predicting Extinction Strain Rate of Syngas-air Nonpremixed Flames