In this study,the flow field structure inside a scramjet combustor is numerically simulated using the flamelet/progress variable model.Slope injection is considered,with fuel mixing enhanced by means of a streamwise v...In this study,the flow field structure inside a scramjet combustor is numerically simulated using the flamelet/progress variable model.Slope injection is considered,with fuel mixing enhanced by means of a streamwise vortex.The flow field structure and combustion characteristics are analyzed under different conditions.Attention is also paid to the identification of the mechanisms that keep combustion stable and support enhanced mixing.The overall performances of the combustion chamber are discussed.展开更多
The Arrhenius law implies that reaction rate is a continuous function of temperature. However,the steady laminar flamelet model(SLFM) does not explicitly give this functional relationship. The present study addresses ...The Arrhenius law implies that reaction rate is a continuous function of temperature. However,the steady laminar flamelet model(SLFM) does not explicitly give this functional relationship. The present study addresses this relation in the SLFM.It is found that reaction rate is not continuous in the mixture-fraction space.As a result,the SLFM is unable to predict local extinction and reignition.Furthermore,we use the unstable branch of the'S-curve'to fill the gap between steady burning branch and extinction one,and find that this modification leads to a continuous dependent of reaction rate on temperature.Thus the modified SLFM can describe the local extinction and reignition.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.12002193)the Shandong Provincial Natural Science Foundation,China(No.ZR2019QA018).
文摘In this study,the flow field structure inside a scramjet combustor is numerically simulated using the flamelet/progress variable model.Slope injection is considered,with fuel mixing enhanced by means of a streamwise vortex.The flow field structure and combustion characteristics are analyzed under different conditions.Attention is also paid to the identification of the mechanisms that keep combustion stable and support enhanced mixing.The overall performances of the combustion chamber are discussed.
基金supported by CAS(KJCX2-SW-L08), 973 Program of China(2007CB814800,2009CB724100)NSFC(11072247,10702074,10732090,50906096)the LNM initial funding for young investigators
文摘The Arrhenius law implies that reaction rate is a continuous function of temperature. However,the steady laminar flamelet model(SLFM) does not explicitly give this functional relationship. The present study addresses this relation in the SLFM.It is found that reaction rate is not continuous in the mixture-fraction space.As a result,the SLFM is unable to predict local extinction and reignition.Furthermore,we use the unstable branch of the'S-curve'to fill the gap between steady burning branch and extinction one,and find that this modification leads to a continuous dependent of reaction rate on temperature.Thus the modified SLFM can describe the local extinction and reignition.
