عرض بسيط للتسجيلة

المؤلفd’Auzay, C. Turquand
المؤلفPapapostolou, V.
المؤلفAhmed, S.F.
المؤلفChakraborty, N.
تاريخ الإتاحة2020-05-14T09:55:45Z
تاريخ النشر2019
اسم المنشورCombustion Science and Technology
المصدرScopus
الرقم المعياري الدولي للكتاب102202
معرّف المصادر الموحدhttp://dx.doi.org/10.1080/00102202.2019.1576651
معرّف المصادر الموحدhttp://hdl.handle.net/10576/14855
الملخصThree-dimensional compressible Direct Numerical Simulations (DNS) have been used to investigate the localized forced ignition of statistically planar mixing layers of biogas/air mixtures for different levels of turbulence intensity and biogas composition. The biogas is represented by a CH4 /CO2 mixture and a two-step mechanism involving incomplete oxidation of CH4 to CO and H2 O, and an equilibrium between the CO oxidation and the CO2 dissociation has been used. This two-step mechanism captures the variation of the unstrained laminar flame speed with equivalence ratio and CO2 dilution with sufficient accuracy when compared with detailed chemistry results. A successful ignition of CH4 /CO2 /air mixing layer initially gives rise to a tribrachial flame structure involving fuel-rich and lean premixed branches on either side of the diffusion flame stabilized on the stoichiometric mixture fraction iso-surface. Long after the energy deposition has ended, the lean branch may merge with the diffusion flame, but edge flame propagation along the stoichiometric mixture fraction iso-surface is observed at all stages. The highest heat release rate (HRR) is obtained on the rich premixed branch irrespective of the turbulence intensity and biogas composition, but its magnitude decreases with increasing CO2 dilution. The most probable edge flame displacement speed decreases in time and converges to its theoretical value for laminar cases. As the turbulence level increases, the edge flame displacement speed assumes a larger range of values, although its mean is consistently lower than the corresponding laminar one. Furthermore, in the turbulent cases, the probability of finding negative values of the edge flame displacement speed has been found to be non-zero. This probability is larger than the one of finding positive values for the cases failing to reach a self-sustained flame propagation without the energy deposition assistance. This becomes more probable as the turbulence intensity and CO2 dilution increase. This is reflected in the diminished burning extent, quantified in terms of burned gas volume, with increasing turbulence intensity and CO2 dilution. - 2019, - 2019 Taylor & Francis Group, LLC.
راعي المشروعThe authors are grateful to the British Council for financial support and to EPSRC (ARCHER, Cirrus) and Newcastle University (Rocket) for computational support. This work was supported by the British Council [Newton Grant] and by the EPSRC [EP/K025163/1].
اللغةen
الناشرTaylor and Francis Inc.
الموضوعbiogas
edge flame
inhomogeneous mixtures
Localized forced ignition
turbulence intensity
العنوانEffects of Turbulence Intensity and Biogas Composition on the Localized Forced Ignition of Turbulent Mixing Layers
النوعArticle
الصفحات868-897
رقم العدد6-May
رقم المجلد191
dc.accessType Abstract Only


الملفات في هذه التسجيلة

الملفاتالحجمالصيغةالعرض

لا توجد ملفات لها صلة بهذه التسجيلة.

هذه التسجيلة تظهر في المجموعات التالية

عرض بسيط للتسجيلة