Reduced mechanism for flames of propane, n ‐butane, and their mixtures for application to burners: Development and validation

Author(s):  
S. Muthu Kumaran ◽  
D. Shanmugasundaram ◽  
Krithika Narayanaswamy ◽  
Vasudevan Raghavan
2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Gregory T. Chin ◽  
J.-Y. Chen ◽  
Vi H. Rapp ◽  
R. W. Dibble

A 28-species reduced chemistry mechanism for Dimethyl Ether (DME) combustion is developed on the basis of a recent detailed mechanism by Zhao et al. (2008). The construction of reduced chemistry was carried out with automatic algorithms incorporating newly developed strategies. The performance of the reduced mechanism is assessed over a wide range of combustion conditions anticipated to occur in future advanced piston internal combustion engines, such as HCCI, SAHCCI, and PCCI. Overall, the reduced chemistry gives results in good agreement with those from the detailed mechanism for all the combustion modes tested. While the detailed mechanism by Zhao et al. (2008) shows reasonable agreement with the shock tube autoignition delay data, the detailed mechanism requires further improvement in order to better predict HCCI combustion under engine conditions.


2014 ◽  
Vol 68 (5) ◽  
pp. 529-539
Author(s):  
Zuozhu Wu ◽  
Xinqi Qiao ◽  
Zhen Huang

A new algorithm based on Computational Singular Perturbation (CSP) is proposed to construct global reduced mechanism. The algorithm introduces species concentrations, species net production rates and heat release rates as integral weighting factors to integrate CSP-pointers, including radical pointers and fast reaction pointers, throughout the computational domain. A software package based on the algorithm was developed to make the reduction process more efficient. Input to the algorithm includes (i) the detailed mechanism, (ii) the numerical solution of the problem for a specific set of operating conditions, (iii) the number of quasi steady state (QSS) species. The proposed algorithm was applied to the reduction of GRI3.0 involving 53 species and 325 reactions leading to the development of a 15-species reduced mechanism with 10 lumped steps. Then the reduced mechanism was validated in a one-dimensional, unstretched, premixed, laminar steady flame over a wide range of equivalence ratio, and excellent agreements between results calculated with the detailed and the reduced mechanisms can be observed.


2009 ◽  
Vol 23 (7) ◽  
pp. 3605-3611 ◽  
Author(s):  
Yu Lv ◽  
Zhihua Wang ◽  
Junhu Zhou ◽  
Kefa Cen

2018 ◽  
Vol 78 ◽  
pp. 327-340 ◽  
Author(s):  
Fan Hu ◽  
Pengfei Li ◽  
Junjun Guo ◽  
Kai Wang ◽  
Zhaohui Liu ◽  
...  

2007 ◽  
Vol 177 (4S) ◽  
pp. 7-7
Author(s):  
Brent K. Hollenbeck ◽  
J. Stuart Wolf ◽  
Rodney L. Dunn ◽  
Martin G. Sanda ◽  
David P. Wood ◽  
...  

2018 ◽  
Vol 34 (3) ◽  
pp. 193-205 ◽  
Author(s):  
Julia Steinbach ◽  
Heidrun Stoeger

Abstract. We describe the development and validation of an instrument for measuring the affective component of primary school teachers’ attitudes towards self-regulated learning. The questionnaire assesses the affective component towards those cognitive and metacognitive strategies that are especially effective in primary school. In a first study (n = 230), the factor structure was verified via an exploratory factor analysis. A confirmatory factor analysis with data from a second study (n = 400) indicated that the theoretical factor structure is appropriate. A comparison with four alternative models identified the theoretically derived factor structure as the most appropriate. Concurrent validity was demonstrated by correlations with a scale that measures the degree to which teachers create learning environments that enable students to self-regulate their learning. Retrospective validity was demonstrated by correlations with a scale that measures teachers’ experiences with self-regulated learning. In a third study (n = 47), the scale’s concurrent validity was tested with scales measuring teachers’ evaluation of the desirability of different aspects of self-regulated learning in class. Additionally, predictive validity was demonstrated via a binary logistic regression, with teachers attitudes as predictor on their registration for a workshop on self-regulated learning and their willingness to implement a seven-week training program on self-regulated learning.


2020 ◽  
Vol 36 (5) ◽  
pp. 852-863 ◽  
Author(s):  
George Gunnesch-Luca ◽  
Klaus Moser

Abstract. The current paper presents the development and validation of a unit-level Organizational Citizenship Behavior (OCB) scale based on the Referent-Shift Consensus Model (RSCM). In Study 1, with 124 individuals measured twice, both an Exploratory Factor Analysis (EFA) and a Confirmatory Factor Analysis (CFA) established and confirmed a five-factor solution (helping behavior, sportsmanship, loyalty, civic virtue, and conscientiousness). Test–retest reliabilities at a 2-month interval were high (between .59 and .79 for the subscales, .83 for the total scale). In Study 2, unit-level OCB was analyzed in a sample of 129 work teams. Both Interrater Reliability (IRR) measures and Interrater Agreement (IRA) values provided support for RSCM requirements. Finally, unit-level OCB was associated with group task interdependence and was more predictable (by job satisfaction and integrity of the supervisor) than individual-level OCB in previous research.


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