Fundamental combustion characteristics of laminar ultra-lean hydrogen/air flames
Résumé
Ultra-lean hydrogen spark ignition engines is a rising solution to mitigate global warming. However, there is a lack of laminar burning velocity measurements under (ultra-)lean conditions at ambient pressure and temperature, which are crucial for validating or optimizing chemical models. Laminar flame speed and burnt Markstein lengths were measured at P u = 0.1 MPa, T u = 303 K and ϕ = 0.28 -0.6, using a constant-pressure spherical bomb. Thus, laminar flame speed showed reasonable agreement with existing literature datasets. However, the evaluated kinetic mechanisms tended to globally underpredict these values. In addition, significant decrease in burnt Markstein length was observed as the mixture becomes leaner, in accordance with the reduction in Lewis number in the ultra-lean region. Comparison between burnt Markstein length theoretical predictions and measured values shows that the model considering overall activation energy and thermal flame thickness highlights quantitative and qualitative agreement with present work.
Domaines
Milieux fluides et réactifsOrigine | Fichiers produits par l'(les) auteur(s) |
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