摘要
加热器是常规高超声速风洞的重要部件,直热式电加热器内部一般由加热圆柱阵列组成,气流通过高温圆柱对流换热实现温度升高,其内部流动通常可以简化为加热圆柱绕流。本研究利用纹影和粒子图像测速法对串联双加热圆柱绕流流场展开实验研究。结果表明:低壁温时两圆柱间分离涡周期性脱落,壁温升高后第一圆柱后分离涡脱落位置后移并接近第二圆柱,当两圆柱间形成稳定回流区时,第二圆柱后的分离涡结构趋近于单圆柱绕流模式;壁流速较低时第一圆柱后分离涡规律脱落,流速超某一阈值时第一圆柱后分离涡突然消失,两圆柱间形成稳定回流区,此时第二圆柱后分离涡再次完整重现,并趋于单圆柱模式。
The heater constitutes a critical component in conventional hypersonic wind tunnels.Within direct-heat electric heaters,the internal fow configuration generally comprises an array of heated columns,where convective heat transfer between the airflow and high-temperature columns facilitates thermal elevation.This internal fow regime can be conceptually simplified as a heated-column-wrapped flow configuration.In this investigation,the fow field characteristics of a series-connected dual-heated cylindrical system were experimentally analyzed through schlieren imaging and particle image velocimetry(PIV).Experimental results revealed that under low wall temperature conditions,the separation vortex between the two columns exhibited periodic shedding behavior.As wall temperature increased,the separation vortex downstream of the first column shifted rearward,approaching the second column,while the vortex structure behind the second column progressively adopted a fow pattern analogous to single-column wrapping upon establishment of a stable inter-column recirculation zone.Furthermore,at low wall flow rates,the first column's separation vortex demonstrated regular shedding cycles.However,when flow velocity exceeded a critical threshold,the primary separation vortex abruptly dissipated,accompanied by the formation of a stable re-circulation zone between the columns.Notably,under these high-fow conditions,the secondary column's separation vortex regenerated completely,ultimately transitioning toward a single-cylinder flow mode.
作者
陈世康
冈敦殿
丰源
米琦
CHEN Shikang;GANG Dundian;FENG Yuan;MI Qi(College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410028,China)
出处
《工程热物理学报》
北大核心
2025年第9期2891-2897,共7页
Journal of Engineering Thermophysics
基金
国家自然科学基金(No.12372282)。
关键词
双加热圆柱绕流
流动分离
粒子图像测速
涡旋脱落
尾流结构
dual-heated cylinder fow
fow separation
particle image velocimetry
vortex shedding
wake flow structure
