论文部分内容阅读
强旋流和钝体绕流均可构造低速回流区以利于高速气体稳定燃烧,本文通过在钝体中心开孔通入旋流气体模拟研究了旋流流动对钝体绕流旋涡脱落的影响规律。计算结果表明,在旋流作用下,钝体绕流涡脱规律更加复杂,涡脱由上下边界层失稳主导变为由旋流管中的旋流涡主导,并且形成的涡尺度增大,在脱落过程中会由于旋涡的破碎产生“点潭”以增强周围涡强度。同时,柱体涡和旋流涡的相互作用可以减小流动阻力,增加回流区长度和回流质量流量,从而强化传热传质,起到强化燃烧增加燃烧稳定性的效果。
The low-velocity recirculation zone can be constructed by strong swirling flow and bluff body flow to facilitate the stable combustion of high-velocity gas. In this paper, the influence of swirling flow on the shedding of bluff bodies around vortices is simulated by introducing the swirling gas through the openings in the bluff body . The calculation results show that the vortex shedding law of bluff bodies is more complicated under the influence of swirling flow, vortex shedding dominated by the instability of the upper and lower boundary layers becomes dominated by the vortex shedding in the vortex tube, and the vortex scale increases, In the process of shedding will be due to the vortex crushing produce “Point Lake ” to enhance the surrounding vortex intensity. At the same time, the interaction between the cylinder vortices and the vortex shedders can reduce the flow resistance, increase the length of the reflux zone and return mass flow, so as to enhance heat and mass transfer and enhance the combustion stability and combustion stability.