654 / 2019-04-21 15:04:24

Research on Reduction Method of Chemical Reaction Mechanism Based on Direct Relation Graph and Its Derivative Methods

direct relation graph; mechanism reduction; threshold; multiple reduction

For the reduction to chemical mechanism with the method of DRG and its derivatives, if only one threshold is selected within the recommended range, there will be a problem of insufficient mechanism reduction. Moreover, the ability of this method to identify redundant components is limited. After fully eliminating redundant components and elementary reactions, one problem will be observed that whatever the threshold is chosen, the component and elementary reactions can not be reduced under the condition of maintaining accuracy continuously. Aiming at the above problems, this paper proposed a method, that the threshold is set from small to large gradually within the recommended range to form multiple reductions. When the reduction ability of one method is exhausted, other methods are cross-used, greatly reducing the component and elementary reactions while maintaining the accuracy of the initial settings. Taking the n-heptane detailed mechanism LLNL3.1 as an example, it was reduced from 654 components and 2827 elements to 162 components and 692 elements by the method proposed in this paper. Compared with the detailed mechanism, the results show that the combustion performance and emission performance of the reduced mechanism have better accuracy, which fully verifies the effectiveness of the reduced method and mechanism.