Numerical description of axisymmetric blue whirls over liquid-fuel pools
Numerical description of axisymmetric blue whirls over liquid-fuel pools
复制标题
液体燃料池上轴对称蓝色涡流的数值描述
DOI：
10.1016/j.proci.2020.06.327
复制
发表时间：
2021
影响因子：
3.4
通讯作者：
Williams, F.A.
中科院分区：
文献类型：
--
作者：
Carpio, J.;Coenen, W.;Sánchez, A.L.;Oran, E.S.;Williams, F.A.
这种数值研究的重点是确定蓝色漩涡的结构，最近发现发生在实验室调查的火旋风时，循环变得足够大，产生涡流崩溃，大大缩短了火旋风，并相应地减少停留时间，使黄色火焰变成蓝色。计算地址轴对称配置的圆形池的液体燃料冲洗和在一个更大的固体水平盘的中心，在其外边缘的可调角度的叶片导致夹带的空气进入一个可控的方位角分量的速度。采用的无量纲守恒方程包括现实的刘易斯数与温度相关的传输系数和一步化学动力学近似，正确地再现层流燃烧速度。浮力和辐射能量传输从火焰到液体表面都考虑在内，后者被发现是必不可少的蓝色漩涡。沿着在燃料表面的蒸发平衡和能量守恒边界条件，流入边界条件由最近开发的固体圆盘上的边界层流动的解提供，而零梯度流出条件应用于旋转上方。控制无量纲参数，除了雷诺数，Damköhler，和弗劳德数，是辐射对流能通量的比率和方位角向内的径向流动速度的比率在边界层的边缘的磁盘。计算出的蓝旋开始的条件以及计算出的蓝旋本身的结构与实验发现的非常相似。
This numerical investigation is focused on determining the structures of blue whirls, recently found to occur in laboratory investigations of fire whirls when the circulation becomes sufficiently large to produce a vortex breakdown that drastically shortens the fire whirl and correspondingly reduces residence times, so that the yellow flames turn blue. The computations address axisymmetric configurations for round pools of liquid fuels flush with and at the center of a larger solid horizontal disc, at the outer edge of which vanes of adjustable angles cause the entrained air to enter with a controllable azimuthal component of velocity. The nondimensionlized conservation equations employed include realistic Lewis numbers with temperature-dependent transport coefficients and a one-step chemical-kinetic approximation that correctly reproduces laminar burning velocities. Buoyancy and radiant energy transport from the flames to the liquid surface are both taken into account, the latter being found to be essential for the blue whirl. Along with the vaporization-equilibrium and energy-conservation boundary conditions at the fuel surface, inflow boundary conditions are provided by a recently developed solution for the boundary-layer flow over the solid disc, while zero-gradient outflow conditions are applied above the whirl. Controlling nondimensional parameters, besides Reynolds, Damköhler, and Froude numbers, are a ratio of radiant to convective energy flux and a ratio of azimuthal to inward radial flow velocity in the boundary layer at the edge of the disc. The computed conditions for the onset of the blue whirl, as well as the computed structure of the whirl itself, bear close resemblance to what was found experimentally.
登录
查看更多内容
影响因子：
3.4
作者：
S. Hariharan;Evan Sluder;M. Gollner;E. Oran
通讯作者：
S. Hariharan;Evan Sluder;M. Gollner;E. Oran
影响因子：
3.7
作者：
Weiss, A. D.;Rajamanickam, P.;Coenen, W.;Sánchez, A. L.;Williams, F. A.
通讯作者：
Williams, F. A.
影响因子：
4.6
作者：
O. Burggraf;K. Stewartson;R. J. Belcher
通讯作者：
R. J. Belcher
影响因子：
2.8
作者：
Zhang, Xiao;Chung, Joseph D.;Kaplan, Carolyn R.;Oran, Elaine S.
通讯作者：
Oran, Elaine S.
求解低马赫瞬态燃烧问题的局部各向异性自适应算法
DOI：
10.1016/j.jcp.2015.11.011
发表时间：
2016
期刊：
J. Comput. Phys.
影响因子：
--
作者：
J. Carpio;J. Prieto;M. Vera
通讯作者：
M. Vera