کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4764493 1423550 2018 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Direct numerical simulation of turbulent channel-flow catalytic combustion: Effects of Reynolds number and catalytic reactivity
ترجمه فارسی عنوان
شبیه سازی مستقیم عددی از احتراق کاتالیزوری کانال جریان آشفته: اثر تعداد رینولدز و واکنش کاتالیزوری
کلمات کلیدی
سه بعدی شبیه سازی عددی مستقیم، احتراق کاتالیستی آشفته هیدروژن، انتقال گرما و جرم متلاشی شده، روش عنصر طیفی،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی

Three-dimensional direct numerical simulations of fuel-lean (equivalence ratio ϕ=0.24) hydrogen/air turbulent catalytic combustion were carried out in a platinum-coated planar channel with isothermal walls and an incoming fully-developed turbulent flow, at two inlet bulk Reynolds numbers (ReH=5700 and 12,360 based on the channel height H) and four global catalytic reaction rates. The turbulent flow laminarization due to heat transfer from the hot catalytic walls was appreciable, with turbulent intensities dropping by 37% and 25% at the channel outlet for the low and high ReH, respectively. The ratio of the local average turbulent hydrogen conversion rate to the corresponding local laminar conversion rate (〈s˙T〉/s˙L) was found to be a monotonically increasing function of streamwise distance, Reynolds number ReH, and catalytic reactivity. Despite the turbulent flow laminarization, 〈s˙T〉/s˙L ratios at the channel outlet reached values up to 170% for the highest ReH = 12,360 and for infinitely-fast catalytic chemistry. A correlation was further established for the ratio of the turbulent hydrogen conversion rate at finite-rate chemistry to the corresponding turbulent conversion rate at infinitely-fast chemistry. The instantaneous local catalytic reaction rates exhibited large fluctuations, which were up to 300% and 500% for the low and high ReH, respectively. Fourier analysis indicated that a diminishing catalytic reactivity acted as a low-pass frequency filter for the overlying fluctuations of the turbulent flow.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Combustion and Flame - Volume 187, January 2018, Pages 52-66
نویسندگان
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